What Is a DRMZ File? A Drumlin PDF That Opens on Phones Too
DRMZ files are PDFs locked with Drumlin Security's DRM, and the free Javelin reader opens them on PC, Mac and mobile with a code. Jump to your question below, or work through it in order.
What Is a DRMZ File? A PDF locked with Drumlin's DRM that also opens on phones
Short answer
DRMZ files are PDFs locked with Drumlin Security's DRM, and they are the kind that also opens on phones and tablets. Drumlin Publisher makes them. The free Javelin reader opens them on Windows, Mac, iPad, iPhone and Android. It asks for an authorization code first.
We could not get any DRMZ files made by Drumlin, because no public sample exists. So we checked what we could: six file-type databases and a set of eight stand-in files. This page says what those checks show and what they cannot show.
To open DRMZ files, read how to open DRMZ files. If yours will not open, start with the ten causes. To see how the code works, read how DRMZ files work.
DRMZ files are PDFs saved in Drumlin Security's locked format. They are the default format, and the free Javelin reader opens them on Windows, Mac, iPad, iPhone and Android. An authorization code decides who can read one.
Picture a course workbook that arrives as workbook.drmz. You tap it on your tablet, and your usual PDF app has nothing to show. Javelin opens instead and asks for a code. That is the idea behind DRMZ files: they can travel anywhere, and the code decides who reads them.
Drumlin's page on offline services calls DRMZ the format for most purposes. It says to choose DRMX only when you need higher security. Drumlin Publisher is the free Windows program that converts PDFs into DRMZ files with rules the publisher sets, like end dates and watermarks.
FileInfo describes DRMZ files as PDFs in a secure, proprietary format that works on computers and mobile devices. It says DRMZ files are like DRMX files but also work on iPad and Android. FileInfo last updated that page in August 2013, so we checked its claims against Drumlin's current pages.
Two sister formats exist. DRMX files give higher security and open on Windows and Mac only. The DRMZ or DRMX section shows how to separate them, and it adds a third form that needs no code.
DRMZ file facts at a glance
| Property | Value |
|---|---|
| Meaning | A PDF saved in Drumlin Security's secure, proprietary DRMZ format |
| Ending | .drmz. The sister ending is .drmx. |
| Made by | Drumlin Publisher, a free Windows program from Drumlin Security Ltd |
| Opens in | The free Javelin reader on Windows, Mac, iPad, iPhone and Android |
| Encryption | Drumlin's pages disagree on the wording: encoded in the FAQ and 256-bit encrypted in the Publisher guide |
| Unlock | An authorization code, checked on Drumlin's server the first time |
| MIME type | None found in six databases. Servers fall back to application/octet-stream. |
| Starts with | Not published. No public header exists for DRMZ files. |
| Safe to open | The file is data that Javelin reads. The risk is the source of the DRMZ file. |
Wrong page? The desktop-only sister format is in the DRMX file guide. Ordinary PDF files are in the PDF file guide. Windows installers like the Javelin setup are in the EXE file guide.
How Do You Know Your File Is a DRMZ File? No public header exists, so check the two labels
No public document names the first bytes of DRMZ files, so no test can prove that your file is one. Two labels help instead. The ending is only a hint, and the bytes inside show what the file is not. If a server calls your DRMZ file generic data, that is no sign of trouble.
Our earlier page on this site listed the text {DRMPDK} as the header of DRMZ files, and FILExt still says that 98 percent of DRMZ files share it. We could not find that header in any Drumlin document. FileInfo, file.org and file-extensions.org list no header at all, so we removed the claim.
The rule book of the file command has no entry for Drumlin, Javelin or {DRMPDK} either. So every file has two labels, and neither one can name DRMZ files for sure. The ending is the first label. The bytes inside are the second. A web server reads the ending, and the file command reads the bytes.
We made eight stand-in files and checked both labels. Seven carried the ending .drmz, and one was a control that ended in .pdf. The built-in Python web server called all seven .drmz files application/octet-stream, the label for unknown downloads.
The file command read the bytes and did better. It named three PDFs, one ZIP package and one text file. It called the two encrypted blobs generic data. That is why web labels cannot confirm Drumlin files, and why servers that send DRMZ files as generic downloads have done nothing wrong.
The script below shows both labels for any file. Save it as check_drmz_label.py and give it the name of your file.
import mimetypes, subprocess, sys
name = sys.argv[1]
by_name = mimetypes.guess_type(name)[0]
if by_name is None:
by_name = 'nothing known for this ending'
by_content = subprocess.check_output(['file', '-b', '--mime-type', name], text=True).strip()
print('The ending says:', by_name)
print('The content says:', by_content)Here is what it printed for three of our stand-ins.
The ending says: nothing known for this ending
The content says: application/pdfThe ending says: nothing known for this ending
The content says: application/octet-streamThe ending says: nothing known for this ending
The content says: application/zipThe script cannot confirm DRMZ files. If the second line says application/pdf or application/zip or shows text, your file is not a locked DRMZ file. If it says application/octet-stream, your file may be a locked DRMZ file, an encrypted blob or random bytes. Only Javelin and the publisher can say which.
Four more clues about your DRMZ file
file command still named them PDFs.
How Does a DRMZ File Work? The file stays locked and the code is a look-up entry
DRMZ files stay encrypted, and the authorization code is a look-up entry on Drumlin's server. The server checks the code against the DocID of the file, its dates and its use count, then authorizes your device. After that first check, DRMZ files open offline.
Think of a hotel door card. The card is not the room. The door checks the card against a list and opens only if the card is on it. The code works the same way. It does not unlock the DRMZ file by itself. Drumlin's server checks it against a list, and Javelin opens the file if the check passes.
The figure follows one code that starts at 2. Drumlin says that count usually covers one computer plus one mobile device. The laptop uses the first count and the phone uses the second. A third device is refused, and the attempt is logged for the publisher. The publisher can then reset the code.
The steps come from Drumlin's FAQ page, its offline page and its Publisher guide. Publishers may also use license files in place of codes. Drumlin offers that option for Windows readers with the Pro edition, mostly as part of custom corporate services.
| Part | What it does |
|---|---|
| Drumlin Publisher | Free Windows program that converts PDFs into DRMZ files and sets the rules |
| The DRM server | Stores the codes and the use counts, and checks them against the DocID of the file |
| The DocID | An ID made for every converted file. It is stored on the server and inside the file. |
| The authorization code | A look-up entry of 9 or more characters. It is normally good for one device, and sets of 2 to 5 are offered by default. |
| Javelin | The free reader that asks for the code and then shows the pages |
The count is the part to remember. Every good check lowers the count by 1. At 0 the code stops working, and later tries are logged. A teacher might get a code that starts at 30, and the publisher switches it off after the class has opened the DRMZ file.
The code does not decrypt anything. Drumlin says DRMZ files stay unchanged and encrypted, and the device is what gets authorized for the DocID. That is why you can rename DRMZ files. The reader ignores the file name, so the authorization and the DocID stay the same.
After the first check, DRMZ files need no internet. Drumlin says authorized files work offline. The first check needs a short connection. Corporate Pro users on Windows with license files can skip it, and so can files that were authorized ahead of time.
Encoded or encrypted?
Drumlin's documents use two words. The FAQ describes DRMX files as strongly encrypted and DRMZ files as encoded. The Publisher guide describes both as proprietary 256-bit encrypted formats. We cannot check either claim, because no public document describes the format. Drumlin offers DRMX for jobs that need higher security.
Drumlin is open about the limit. It says no system can fully stop a determined attacker, and it built these files to deter casual copying. This page explains how the system works and how to open files. It does not cover ways around it.
What Can the Publisher Control in a DRMZ File? Dates, views, printing, notes, watermarks and screen capture
The publisher sets the rules when making DRMZ files: dates, view counts, printing, copying and watermarks. Printing works on Windows and Mac only, so phones can read DRMZ files but cannot print them.
The rules make DRMZ files different from ordinary PDFs. They are set in Drumlin Publisher and enforced by the Javelin reader and the DRM server. The table lists the rules we found in the FAQ and the Publisher guide.
| Rule | What it does and the limit |
|---|---|
| Dates | Start and end dates, or an "expires after" period of up to 999 days from authorization. No expiry sets the end date 200 years out. Limit: An absolute end date cannot be re-enabled, so the publisher must issue a new file. |
| Views | Unlimited views or a set number. Limit: Set by the publisher and checked against the server. |
| Printing | Off, print counts or limits on total pages. Limit: Windows and macOS only. Use an attached printer. The Mac reader has no double-sided printing. |
| Notes and highlights | Work on every platform. Limit: They live in separate files, so a new DocID can cost you your notes. |
| Watermarks | Static marks are added before conversion. Dynamic marks can show the code, the device ID or the username. Limit: Static marks cannot be removed from the secured file. |
| Screen capture | The Disable option blocks most program-driven captures. Limit: Android always blocks hardware capture. iOS and iPadOS only make capture hard. No system stops a photo of the screen. |
Think of two kinds of end date. An absolute date is a closing day for everyone. An "expires after" date is a rental that starts when you first enter your code, and new or re-enabled codes can renew it.
Your own notes live in separate files next to the secured DRMZ file. Drumlin says desktop readers can show them as lists and export them. On Windows, File and then Create Backup Copy saves the document with its notes, and Restore Backup brings them to another PC.
We did not test any of these rules. We had no file made by Drumlin and no copy of Drumlin Publisher, so every rule here comes from Drumlin's own pages. If a rule behaves in another way on your device, trust Drumlin over this page.
DRMZ or DRMX: Which One Do You Have? One opens on phones too, and a third form needs no code
DRMZ is the default format. It opens on Windows, Mac, iPad, iPhone and Android. DRMX gives higher security and opens on Windows and Mac only. A third form, the self-authorizing DRMZ file, needs no online check.
Both formats come from one program, Drumlin Publisher. The Drumlin Publisher guide says the output keeps the name of the source and takes the new ending, so ftse.pdf becomes ftse.drmz. Its command line examples assume DRMZ as the default file type.
| Format | Where it opens |
|---|---|
| DRMZ | Windows, Mac, iPad, iPhone and Android. The default, and the choice for most uses. |
| DRMX | Windows and Mac only. Higher security, for PC and Mac use only. |
| Ordinary PDF | Every Javelin reader. Javelin also opens PDFs with no DRM. |
| Self-authorizing DRMZ | Javelin, with no online check. A licensed option. The file itself can be copied. |
Drumlin's offline page sums it up: all Javelin readers show PDF and DRMZ files, while DRMX files need the Windows or Mac reader. So a reader on a tablet needs DRMZ. If a publisher sends DRMX files and you read on an iPad, ask for DRMZ copies.
The self-authorizing DRMZ file
Drumlin offers a variant that needs no code. Its Publisher guide says self-authorizing DRMZ files ask for no authorization. The file cannot be saved in other formats, and its contents cannot be copied. The publisher can still set an end date, add watermarks and allow or block printing.
There is a catch, and Drumlin states it. With no online check, the file itself can be duplicated. So the guide suggests an end date. It calls these files ideal for selected corporate, fieldworker and education settings.
Drumlin's release notes show when support arrived. Drumlin Publisher v068 for Windows added it as a licensed option on 13 September 2019. Javelin3 for Windows followed on 13 and 17 September 2019, and Javelin3 for Mac on 20 September 2019. Drumlin documents nothing about the option on phones and tablets, so ask the publisher before you rely on it there.
Which Javelin version do you need?
Drumlin's downloads page lists one Javelin for every system. Find the row that matches yours. The Windows reader is an .exe setup, and the Mac reader comes as a zipped app. For older systems than these, Drumlin says to contact them.
| System | Reader and note |
|---|---|
| Windows 8, 10 and 11, outside S mode | Javelin3, version 3.1.0.48. A setup .exe for most users. Javelin3Pro has the same version and is for corporate use. |
| macOS 10.13 or later | Javelin3, version 3.06.00. A zipped app from Drumlin. |
| Android 7 or later | Javelin3, version 3.00.98. Free from Google Play. A Chromebook can use it too. |
| iOS and iPadOS 9 or later | Javelin, version 3.01.07. Free from the App Store. |
The Wikipedia entry for Javelin lists older systems than the downloads page does, like Windows 7 and macOS 10.6. We follow Drumlin's page, which we read in October 2026. We did not try any Javelin version on DRMZ files.
Regenerating is safer for DRMZ. Drumlin says you can make DRMZ files again from the same source PDF name. Existing authorizations keep working and the DocID stays the same. If you change the counts or dates, readers must use Remove Authorization and enter a code again. For DRMX files, Drumlin advises renaming the source first.
What Do Six File-Type Databases Say About DRMZ Files? None of them knows the ending, and that shapes what servers do
We looked up .drmz in six file-type databases and in the rule book of the file command. None lists .drmz or .drmx, and all six list .pdf. That gap is why web servers fall back to a generic label for DRMZ files.
File-type databases link endings to media types, the labels that show browsers what a file is. IANA keeps the official list, and most servers ship a copy of the common entries. When an ending is missing, the software has to guess.
In October 2026 we looked up .drmz, .drmx and .pdf in Debian media-types 10.1.0, Apache httpd trunk, nginx master, shared-mime-info 2.4, Python 3.13 and mime-db 1.54.0. We used .pdf as a control, because every database should know it.
The figure shows a blank for .drmz and .drmx in every column. The control, .pdf, is filled in everywhere. The mime-db list is the largest, with 2,522 media types. It has no entry either. It does list .drm, but as a Procreate Dream file, which has nothing to do with Drumlin.
Our tools could not read the IANA registry page in full. So we used mime-db as the evidence, because it copies the IANA list and adds entries from other sources.
We also searched the 8.5 MB rule book of the file command (libmagic 5.45) and the byte patterns of shared-mime-info. We looked for the words Drumlin, Javelin and {DRMPDK} and for the endings drmz and drmx. Nothing matched.
What the empty databases mean
file command and shared-mime-info have no pattern for it, so neither can name a genuine DRMZ file.
Read the study with care. It shows what common software knows about the ending. It does not show how Javelin treats a genuine DRMZ file, and we had none. The eight stand-ins are not made by Drumlin.
What Does Our Expert Say About DRMZ Files? A note from Neeraj Singh on asking for the code first
Ask the publisher for a working authorization code before you try any other fix for DRMZ files. They work as permission checks more than locked boxes, and the check happens on Drumlin's server.
Expert insight
“DRMZ files are more like tickets than locked boxes. The reader asks Drumlin's server if your device may read the DRMZ file. In our checks, six databases knew nothing about the ending, so web servers call these files generic downloads. Ask the publisher for a working code first, then install Javelin from Drumlin.”
Why the code comes first
The code is the one thing the system checks. The count, the dates and the status all live on the server. When the count reaches 0, the DRMZ file stays closed and the attempt is logged. Publishers can reset codes, for example when you change to a new device after some years.
That also explains why apps that read ordinary PDFs cannot open DRMZ files. They cannot ask Drumlin's server anything. The lock is by design and is no flaw in your PDF app.
We do not cover ways around the lock on DRMZ files. One directory says to decrypt the DRMZ file and then use any PDF converter, without saying how. FILExt points to an online viewer and asks you to switch off your ad blocker first. We did not test either one, and we would not upload licensed files to strangers' sites.
Save the file and the email. Store the first copy of the DRMZ file with the message that has the code. If Javelin asks for the code again, for example after Remove Authorization, you need both.
How Do You Open DRMZ Files? Javelin on Windows, Mac, iPad, iPhone or Android, plus a code
Install the free Javelin reader for your device, open the DRMZ file in it and enter the authorization code when it asks. Javelin works on Windows, Mac, iPad, iPhone and Android. The first check needs the internet.
DRMZ files are the easy kind to open, because they work on almost any device you own. Most trouble comes from the wrong app, a used-up code or a network that blocks the check. The sections after this one cover those cases.
| Program | What it does |
|---|---|
| Javelin PDF Reader | The free Drumlin reader for Windows, Mac, iPad, iPhone and Android |
| Javelin3Pro | A Windows edition for corporate use that does not need the DRM web service. Drumlin calls it not normally required. |
| Drumlin PDF Reader and Publisher | A free Windows program that makes DRMZ files and reads them, says FileInfo |
| Javelin3 for Android on a Chromebook | Chromebooks can install the Android reader from Google Play, says Drumlin |
| Browsers and ordinary PDF apps | They cannot show the pages of a locked file, because the server must authorize the device first |
We did not start any of these on DRMZ files made by Drumlin. The directories agree on the main reader but not on the systems. FileInfo lists Javelin for Windows, Mac, iOS and Android. file.org lists Javelin and Javelin3 for Windows only and marks both as user submitted. Drumlin's downloads page settles it with readers for all five systems.
Open DRMZ files on Windows
- Install the free Javelin reader from Drumlin Security. Drumlin lists Javelin3 for Windows 8, 10 and 11, outside S mode.
- Open the DRMZ file in Javelin. Stay online, because the first authorization needs the internet.
- When Javelin asks for an authorization code, enter the one from the publisher.
- If the check fails on a company network, try Test Connection in the Tools menu and Web Authorization in the File menu. Drumlin lists both for network problems.
- If Javelin says the code has no uses left, ask the publisher to reset it. The causes section lists more reasons.
These steps follow Drumlin's downloads page, its FAQ and its offline page. We did not start Javelin on DRMZ files.
Open DRMZ files on a Mac
- Download Javelin3 for Mac from Drumlin Security. The downloads page lists version 3.06.00 for macOS 10.13 or later, as a zipped app.
- Unzip it, drag the Javelin icon to your Applications folder and double-click it.
- Close Terminal first. Drumlin says Javelin warns you and closes if Terminal is open.
- Open the DRMZ file by double-click, or choose it from the Recently opened list in the File menu. Javelin asks for the code before it shows the DRMZ file.
Drumlin's Apple Mac page says the Mac reader is a signed download. The FAQ adds that it is not in the Mac App Store. Printing works on a Mac, but double-sided printing does not.
Open DRMZ files on an iPad or iPhone
- Install Javelin from the App Store. Drumlin lists version 3.01.07 for iOS and iPadOS 9 or later, and it is free.
- Open the DRMZ file in Javelin, or paste a download link into its built-in downloader. Drumlin suggests simple links and file names.
- Enter the authorization code and stay online for the first check.
- Watch the file size. Drumlin advises keeping DRMZ files under 50 MB where possible, because a mobile device gives an app memory in 64 MB chunks.
Drumlin says screen capture is made hard on iPhone and iPad but not blocked, and text to speech does not work there. Drumlin lists printing for Windows and macOS only.
Open DRMZ files on Android
- Install Javelin3 from Google Play. Drumlin lists version 3.00.98 for Android 7 or later, and it is free.
- Open the DRMZ file in Javelin3. If Android asks which app to use, choose Javelin3 and Always to make it the default.
- Enter the code and stay online for the first check.
Drumlin says hardware screen capture is always off on Android and text to speech works there. A Chromebook can install the same Android reader from Google Play.
When you cannot install anything
Some offices bar new software. Drumlin's offline page mentions Webdoxx, a separate online service that opens secured PDFs in a web browser. It is meant for sites with strict network rules. Ask the publisher whether they use it, because it needs its own setup. We did not test it.
Where the code for DRMZ files comes from
The publisher sends it with your DRMZ file. The offline page says codes are typically 9 characters or more and normally good for one device. Sets of 2 to 5 are offered by default, and larger counts on request. A shop can send codes after a sale. Drumlin names Linklok, Fetchapp, Getdpd, SendOwl, PayLoadz and SoftSeller for that job.
Publishers can also make codes in bulk. Subscribers create 5 to 50 at once for every document, and one code can work across several documents. The Publisher guide says codes expire 3 years after creation, unless the publisher sets another date.
Single-file conversions in Publisher come with free test codes for up to 5 devices. So publishers can check DRMZ files on laptops, phones and tablets before sending them out.
Tip. The reader costs nothing. The only thing you must get from someone else is the code.
Are DRMZ Files Safe to Open? The file is data, and the risk is where it came from
DRMZ files are data that Javelin reads, so the risk is the source. Install Javelin only from Drumlin or your official app store. Take care with any EXE sent in place of the file. Never type a code into a site that Drumlin did not name.
DRMZ files are protected PDF data. Reading them needs Javelin and, in most cases, a code. The usual risks are around the file: fake download pages for the reader, files from unknown senders and sites that ask for your code.
We did not test Javelin or any DRMZ file made by Drumlin. Our stand-ins show how ordinary tools label unknown files, and nothing more. The table lists what to check, and the last column names the source.
| Check | What to do and the source |
|---|---|
| The reader | Get Javelin from Drumlin Security or from your official app store. FILExt points to an online viewer that asks you to switch off your ad blocker. We did not test it. Source: FILExt page, October 2026. |
| Converter sites | A DRM file is usually licensed content. Do not upload one to a stranger's site. Source: Our advice. |
| The code | Type it only into Javelin. The first check goes to the DRM server over the internet. Source: Drumlin offline page. |
| The network | A network that blocks the DRM server can look like a bad code. In Windows Javelin3, Test Connection in the Tools menu helps you check. Source: Drumlin downloads page. |
| What the publisher sees | Usage is tracked centrally, and marks on the page can show your code, device ID or username. Source: Drumlin offline page and FAQ. |
| A self-authorizing file | It needs no code, so anyone can copy it. Treat a file from an unknown sender like any other download. Source: Drumlin Publisher guide. |
What DRMZ files say about you
Drumlin says publishers can reset, disable, track and report on codes. Dynamic watermarks can show the code, the device ID or the username on the page. So DRMZ files can show the publisher which code was used and when. That is the point of the system.
Sharing DRMZ files and codes does not work well. The count belongs to the devices that were authorized, and a code that is used up on one device fails on the next. Drumlin logs those tries for the publisher.
Do not trust a free DRMZ opener. The page for a free DRMZ viewer that you find by search may not come from Drumlin. Use the Javelin reader from Drumlin Security or an official store, and read the guide to Windows EXE installers before you start any installer.
Why Will Your DRMZ File Not Open? Ten causes, and what to do about every one
Most DRMZ files that will not open fail at the app or at the code check, not inside the file. Check the app first. Then check the code, the dates, the use count and the network.
We do not repair the bytes of DRMZ files. No public document describes their parts, so there is nothing for us to patch. The ten causes below come from Drumlin's own pages, in the order we would check them.
| Cause (number) | What you see and the fix |
|---|---|
| Wrong app (1) | Your usual PDF app or browser tries the DRMZ file and shows an error. Fix: Open the DRMZ file from inside Javelin. On Android, choose Javelin3 and Always to make it the default. |
| Old system or reader (2) | Javelin will not install, or an old version cannot read the file. Fix: Install the current Javelin for your system. Drumlin lists Windows 8 or later, macOS 10.13 or later, Android 7 or later and iOS or iPadOS 9 or later. For older systems, contact Drumlin. |
| No code (3) | Javelin asks for an authorization code and you have none. Fix: Ask the publisher. A tool cannot make a code. |
| Code used up (4) | The code worked on your devices and now fails, because its count is 0. Drumlin logs the later tries. Fix: Ask the publisher to reset the code, for example after you change devices. |
| Code disabled (5) | The publisher set the count back to 0, as a teacher might after the class has opened the file. Fix: Ask why, then ask for a new code. |
| File expired (6) | The end date has passed. An absolute end date cannot be re-enabled. Fix: The publisher must issue a new file. A new or re-enabled code renews an "expires after" file. |
| No connection for the first check (7) | The first authorization needs the internet, and a company network may block the DRM server. Fix: Try another network. On Windows, use Test Connection in the Tools menu or Web Authorization in the File menu. Javelin3Pro does not need the web service. |
| A newer version of the file (8) | The publisher issued the DRMZ file again with new counts or dates. Fix: Choose Remove Authorization in the File menu, then enter a valid code again. If the file got a new DocID, your old notes may be gone. |
| A large file on a phone (9) | Big files may fail on phones, because Drumlin advises keeping DRMZ files under 50 MB where possible. Fix: Ask the publisher for smaller files. |
| Damaged or not DRMZ files (10) | The download was cut off, or the file is another kind. Fix: Download it again, then use the label script to see what the file is. |
What to send the publisher
Most fixes depend on the publisher, who controls the codes, the dates and the DRMZ files. A short message gets a faster answer. Include the details below.
Subject: DRMZ file will not open
File name: workbook.drmz (add the size in bytes)
Code: the code you were sent
Device: Windows 11, macOS 14, iPad or Android, and the Javelin version
What happens: the exact words Javelin shows
When it last worked, and whether you changed devicesOne more fix helps with printing on Windows and Mac. If your print quota is used up, choose Remove Authorization in the File menu and enter a valid code again to get a new quota. Drumlin advises publishers to set the print count to unlimited and limit total pages instead.
What no tool can fix
Do not try random tools. A tool that claims to open any DRMZ file cannot ask Drumlin's server for permission. Ask the publisher first.
How Do You Make or Convert a DRMZ File? Drumlin Publisher makes them, and the publisher decides on the way back
Make DRMZ files by converting PDFs in Drumlin Publisher, the free Windows program. Going back to PDFs is the publisher's decision. Drumlin documents no way to convert DRMZ files back to ordinary PDFs, and we found no converter that shows a working one.
Making DRMZ files is quick. Drumlin says a conversion takes 1 to 2 seconds per file, with no limit on how many files you convert. The harder question is the way back, and that answer belongs to the person who owns the source PDF.
| Direction | What we found and the source |
|---|---|
| PDF to DRMZ | Yes, with Drumlin Publisher. DRMZ is the default format. Source: Drumlin Publisher guide. |
| PDF to self-authorizing DRMZ | Yes, as a licensed option on the Permissions tab. Source: Release notes; Publisher guide. |
| DRMZ to DRMX | Make a new file from the source PDF and choose DRMX for higher security on PC and Mac. Source: Drumlin offline page. |
| DRMZ to PDF | Not described by Drumlin. Ask the publisher for the source PDF. Source: Not documented. |
| Self-authorizing DRMZ to other formats | Blocked. Drumlin says these files cannot be saved in other formats. Source: Drumlin Publisher guide. |
Make DRMZ files
- Install Drumlin Publisher on a Windows PC and sign in. New users can register from the sign-in screen.
- Add one or more source PDFs, or an entire folder of them.
- Choose a folder for the output.
- Make DRMZ the file type. Then open the Set Permissions tab, choose the rules and press SAVE SETTINGS.
- Add watermarks if you want them.
- Press Create Secure PDFs.
The guide to Drumlin Publisher asks for source PDFs of version 1.6 or earlier, with no embedded media, no 3D models and no Adobe-style security. Write links out in full, and avoid spaces and special characters in file names. Output keeps the source name, and a personalized file adds the name of the reader.
Single-file conversions come with free test codes for up to 5 devices. Batches do not, so make the codes on the Codes tab. The guide also describes a command line for batch files and a PublishingHistory.csv log of source and output names. We did not test any of it.
Make DRMZ files again
DRMZ files are the forgiving kind. The guide says you can make them again from the same source PDF without renaming it. The DocID is reused even if the output is renamed, and readers who are already authorized keep working. If you change the counts, readers must use Remove Authorization and enter a code again.
For a new version that current readers should open, Drumlin says they must use Remove Authorization first. Then they enter a new or reset code.
Go back from DRMZ files to PDFs
Ask the publisher. The source PDF stays on the publisher's PC, and Drumlin describes no way to rebuild it from DRMZ files. If you need to print or share pages, ask the publisher to change the rules and issue a new file.
Search results show pages that offer DRMZ to PDF. We found none that shows a method Drumlin documents, and FileInfo lists no converter for DRMZ files. We did not test a converter, and we do not cover DRM removal.
Make DRMZ files on a Mac
Drumlin Publisher works on Windows only. Drumlin's Mac page says to use virtualization software or a dual-boot setup to get Windows on a Mac. It names Parallels Desktop as the recommended choice. Apple Boot Camp and VMware Fusion are listed for Intel Macs.
Keep the source PDF. If you publish DRMZ files, keep the source PDF and the codes file. Drumlin's command line backs up the old output and codes file when you repeat a command, but the source PDF is yours to guard.
What Else Looks Like a DRMZ File? .drmx, .drm and directory pages that mislead
Not every file near .drmz is a DRMZ file. DRMX files are the sister format, and ordinary PDFs can wear the ending. Directory pages also disagree on what DRMZ files are, so check them against Drumlin.
Anyone can change an ending. This table lists endings you may meet near .drmz. The FileInfo page for DRM files shows more unrelated neighbors.
| Ending | What it is and the source |
|---|---|
| .drmz | A Drumlin secured PDF that opens on computers and mobile devices. Source: Drumlin; FileInfo. |
| .drmx | A Drumlin secured PDF for Windows and Mac only. Source: Drumlin; FileInfo. |
| An ordinary PDF. Javelin opens these too. Source: Drumlin offline page. | |
| .drm | Unrelated uses. mime-db lists it as a Procreate Dream file. Source: mime-db 1.54.0. |
| .epub | A standard ebook format. Drumlin Publisher converts PDFs, not ebooks. Source: Drumlin Publisher guide. |
| .zip | A ZIP package, like one of our stand-ins. Source: Our label test. |
Where directory pages disagree
Four directories describe .drmz, and they do not agree. FileInfo calls it a secure PDF for computers and mobile devices. file.org lists Windows only. file-extensions.org calls Javelin multiplatform and says Drumlin's apps on iOS and Android use the format.
The FILExt page goes further. It calls DRMZ files mainly eBooks and names DRMPDK as the main app. It also says 98 percent of DRMZ files share the header {DRMPDK} and puts a typical size at 27 MB.
We found none of those claims in the Drumlin pages we read. Drumlin describes PDFs, Javelin and Publisher. It names no DRMPDK program, no ebook use and no {DRMPDK} header. When a directory conflicts with Drumlin, trust Drumlin.
Other ways to lock a PDF
Adobe-style protection puts passwords or rules inside normal PDFs. DRMZ files work in another way, with a server check. Drumlin advises publishers to avoid Adobe-style security in source files. The guide to ordinary PDF files explains the ordinary format, and the guide to DRMX files covers the sister format.
What Is the DRMZ File Format Made Of? The few facts we could check, and what no document says
Little about the DRMZ format is public. We could check who makes DRMZ files, where they open, how codes behave and what the databases know. We could not check headers, versions or layouts, because no public document gives them.
| Part | What we could check |
|---|---|
| Maker | Drumlin Security Ltd, which says it has offered secure PDF distribution since 2006. |
| Kind | FileInfo calls it a PDF saved in a secure, proprietary format that works on computers and mobile devices. |
| Encryption | The FAQ says encoded and the Publisher guide says 256-bit encrypted. No algorithm is named. |
| Platforms | Windows, Mac, iPad, iPhone and Android, says Drumlin. |
| DocID | One per converted file, stored on the DRM server and inside the file, says the FAQ. |
| Source limits | PDF 1.6 or earlier, with no embedded media, 3D models or Adobe-style security. |
| File name | The reader ignores it, so you can rename DRMZ files, says the FAQ. |
| MIME type | None in the six databases we checked in October 2026. Servers fall back to application/octet-stream. |
| Header | None published. FileInfo, file.org and file-extensions.org list none. FILExt names {DRMPDK} with no source. |
| File command |
The file command 5.45 and shared-mime-info 2.4 have no pattern for it.
|
| Wikipedia | The Javelin PDF Reader article names DRMX and DRMZ as Drumlin's formats for encoded and encrypted PDFs. |
About the values we list
The facts about DRMZ files come from Drumlin's pages, from FileInfo, FILExt, file.org, file-extensions.org and Wikipedia, and from our own checks of six databases and eight stand-in files. We read them in October 2026. Drumlin's Publisher guide is dated 9 December 2025, and its release notes list dated entries. Pages without dates may have changed since.
The Wikipedia article cites Drumlin's downloads page. It lists older systems than that page does today. FileInfo's page dates from 2013. When two sources differ, we follow Drumlin's current pages.
What we left out
We did not test Drumlin Publisher, Javelin on any system, Apple silicon, Chromebooks, license files, self-authorizing DRMZ files or Webdoxx. We also left out the old {DRMPDK} header, because we found it in no Drumlin document.
Our stand-in files are not made by Drumlin. We name no converter or viewer other than Drumlin's own, because we found none that we could check. We name no prices.
Sources checked
For the formats and the system, see the Drumlin offline services page, the Drumlin FAQs, the Drumlin Mac page and the Publisher guide PDF. Also see the Drumlin downloads page for Javelin, the Drumlin release notes and the Drumlin home page.
For the extension, see FileInfo for DRMZ, file.org and file-extensions.org. For the reader, see the Wikipedia article on Javelin. For media types, see the IANA registry.
Every database count and label came from the files and scripts in our research folder.
Frequently Asked Questions About DRMZ Files
What is a DRMZ file?
DRMZ files are PDFs saved in the secure, proprietary format of Drumlin Security. Drumlin Publisher makes them, and the free Javelin reader opens them on Windows, Mac, iPad, iPhone and Android. Every file needs an authorization code, which a Drumlin server checks the first time. DRMZ is the default format, and DRMX is the sister format for higher security.
How do I open a DRMZ file?
Install the free Javelin reader for your device, then open your DRMZ file in it. Javelin asks for an authorization code before it shows the pages, and the first check needs the internet. The publisher sends the code. After that, the DRMZ file opens offline.
Can I open a DRMZ file on my phone or tablet?
Yes, DRMZ files open on phones and tablets. Drumlin lists Javelin for iPad and iPhone in the App Store and Javelin3 for Android in Google Play. Both are free. Printing works on Windows and Mac only, so phones can read the DRMZ file but cannot print it.
What is the difference between DRMZ and DRMX files?
Both come from Drumlin Publisher. DRMZ is the default and opens on Windows, Mac, iPad, iPhone and Android. DRMX gives higher security and opens on Windows and Mac only. If you need to read on a tablet, ask the publisher for a DRMZ file.
Where do I get an authorization code for a DRMZ file?
The publisher who made your DRMZ file sends it, often by email or in shop receipts. Codes are typically 9 or more characters and are normally good for one device. Sets of 2 to 5 are offered by default. Tools cannot make codes, because the Drumlin server keeps the list.
Why does Javelin say my code is not valid?
The usual causes are used-up counts, disabled codes, expired DRMZ files and networks that block the Drumlin server. Drumlin says every code has a use count, and the server logs tries at 0. Ask the publisher to reset or replace the code. If your DRMZ file expired on an absolute date, the publisher must issue a new file.
Can I use a DRMZ file offline?
Yes, after the first check. Drumlin says authorized DRMZ files work offline. The first authorization needs a short internet connection, unless you use Windows Pro license files or files that were authorized ahead of time.
How do I know if a file is a DRMZ file?
No public document names the first bytes of a DRMZ file, so no test can prove it. A web server will call it application/octet-stream, because six file-type databases have no entry for .drmz. You can rule out lookalikes with the `file` command: PDF, ZIP and text results mean the file is something else.
Can I convert a DRMZ file to PDF?
Drumlin documents no way to convert a DRMZ file back to an ordinary PDF. The publisher keeps the source PDF and can issue new files with other rules. We did not test any converter, and we found none that shows a method Drumlin documents.
Is a DRMZ file safe to open?
DRMZ files are data that Javelin reads, so the risk is the source. Get Javelin from Drumlin Security or an official store, and never type a code into a site that Drumlin did not name. The publisher can track usage, and marks on the page can show your code, device ID or username.
What is a self-authorizing DRMZ file?
It is a DRMZ file that needs no authorization code. Drumlin says it cannot be saved in other formats and its contents cannot be copied. Because it has no online check, the DRMZ file itself can be duplicated, so Drumlin suggests an end date. Support began in September 2019.
How do I make a DRMZ file?
Use Drumlin Publisher, the free Windows program. Sign in, add your source PDFs, set a folder and the rules, then press Create Secure PDFs. Make DRMZ files from sources that are PDF 1.6 or earlier, with no embedded media or Adobe-style security. On Macs, use Windows in a virtual machine.
Still Stuck With a DRMZ File? Nine routes out, depending on what went wrong
Go to where the code comes from. Ask the publisher, because tools cannot make a code.
Start with the list of causes. The wrong app, a used-up code and a blocked network explain most cases.
Is it a DRMX file? The page on the DRMX format covers the sister format that opens on Windows and Mac only.
Is it an ordinary PDF? The page on PDF documents explains the format that Javelin also opens.
Do you need the Javelin installer? The page on EXE files and the page on DMG files explain the Windows and Mac installers.
Is it an ebook? The page on EPUB files explains the open ebook format that one directory mixes up with DRMZ files.
Is it a ZIP package? The page on ZIP files explains the container that one of our stand-ins used.
Do you want to make one? See how to make DRMZ files with Drumlin Publisher.
Is it a file type you do not know? Browse the file extension resource library, or send it to us on the submit a file type page.