PDF Assembler
Your documents never
leave your computer.
Merge, split, compress and password-protect PDFs on your Mac or PC.
Images and text files become pages too.
Paid once, no subscription
Why an app instead of a website
Websites like Smallpdf, iLovePDF or Adobe's online tools upload your files to their servers to work on them. That's fine for a public document, less so for a contract, a payslip or a medical letter, and many workplaces don't allow it. PDF Assembler does its work on your own computer instead.
| Typical online PDF tool | PDF Assembler | |
|---|---|---|
| Where the work happens | On their server, after you upload the file | On your computer |
| Works offline | No | Yes |
| Account required | Often, after the first few files | No |
| Pricing | Usually a monthly subscription | Paid once |
| File size and daily limits | Common on free plans | None |
There's a longer page on what uploading a document exposes.
How it works
Add your files, put them in order, and save.
Add
Drop in PDFs, images and text files, or a whole folder, and sort them by name or date added.
Arrange
Drag files into order, or switch to Pages to move, rotate or delete single pages. Anything can be undone.
Save
One PDF, one PDF per file or one PDF per page, made smaller or protected with a password if you like.
What it does
Merge
Any number of PDFs into one, in the order you choose.
Split
One PDF per source file, or one per page. To extract a range, delete the rest.
Compress
Shrinks the photos and scans inside a PDF. The text stays sharp and selectable. Files full of photos often get 85 to 95% smaller.
Images to PDF
PNG, JPEG, TIFF, GIF, BMP and WebP, plus HEIC on macOS. Each image becomes a page.
Documents to PDF
Plain text, Markdown and RTF. On Windows, RTF keeps only its text, and Arabic, Hebrew, Hindi or Thai text isn't laid out correctly; the app warns you when a file has it.
Password protection
Lock what you save with a password: Standard (AES-128), which every reader opens, or More secure (AES-256). You can also add PDFs that are already protected, if you know their password.
Annotations
Keep comments, highlights, links and form fields as they are, keep only the links and forms, or remove them all. The pages stay the same.
Privacy
- Nothing is uploaded. Files are read from your disk and saved back to it.
- It works offline. The app makes no network requests.
- No account. There's nothing to sign in to, and the app has no analytics or crash reporting.
After a save, the app may ask you for a review, three times at most. On Windows it is a card in the app, whose first button opens the Microsoft Store's review page; on a Mac it is Apple's own rating prompt. Nothing about your documents is part of it.
PDF Assembler collects no data. The privacy policy lists the few settings it keeps on your computer.
Eight languages
The app opens in your computer's language if it's one of these, and in English otherwise. You can change it at any time from the header, without restarting.
- English
- Français
- Deutsch
- Italiano
- Español
- Português (BR)
- 日本語
- 简体中文
Details
| Price | Paid once, at the price your store shows. No subscription, no in-app purchases. |
|---|---|
| Windows | Windows 11, or Windows 10 version 1809 or later. 64-bit. |
| macOS | macOS 14 Sonoma or later. |
| Reads | PDF · PNG, JPEG, TIFF, GIF, BMP, WebP (HEIC on macOS) · TXT, Markdown, RTF |
| Writes | PDF, optionally with an AES-128 or AES-256 password |
| Made in | Switzerland |
Questions people ask
How do I merge PDFs without uploading them?
Use an app that works on your own computer. In PDF Assembler, drop the files in, drag them into order and save. Nothing leaves your computer.
How do I split a PDF or keep only some pages?
To split, go to the Save step, open Advanced options and set Output to “One PDF per file” or “One PDF per page”. To keep only some pages, delete the others in the Pages view, then save. Ctrl+Z (⌘Z on a Mac) brings back a deleted page.
What does the new PDF keep?
All the pages, including fillable forms unless you remove them under Annotations. Extras such as bookmarks and attached files are not carried over, and neither are limits like “no printing”. This is also true when you only compress or protect a file, so keep the original if you need those extras.
Can I add a password to the PDF?
Yes. On the Save step, open Advanced options, set Protect to Standard (AES-128) or More secure (AES-256), and type a password. The app doesn't save your password anywhere. Anyone who has it can open, print and copy the file.
Will a protected PDF open in other apps?
Yes, in Adobe Acrobat, Chrome, Edge and every other reader I tested. The one exception is Apple's Preview and Quick Look on the Mac, which don't follow the PDF standard for passwords: they can reject the right password when it contains letters such as é, ü or パ. If the file will be opened there, choose Standard (AES-128): it takes only plain letters (a to z), digits and punctuation, and Preview opens it.
Step by step: combine photos into one PDF, make a PDF smaller, or merge PDFs on Windows without Acrobat.
Get PDF Assembler
Paid once, no subscription.