For Windows 10 and 11
Boost your PDF productivity.
AJ Pdf edits, converts, signs, redacts and archives PDFs on your own PC. Buy it once, own it. One year of updates included.
€25
one-time, no subscription
Try the full app free for 7 days first. No account, no card. When the week is over, buy a licence key and keep everything you made.
Windows installer, about 75 MB. No admin rights and nothing else to install. ARM PC? Take the arm64 build.
AJ Pdf. Your essential document tool, on your own PC.
Everything you expect from a professional PDF suite, built on an engine written from the ground up for Windows.
Edit text and images
Change wording, fix a typo or swap a picture directly on the page. Text reflows inside its block and keeps the original font.
Create and convert PDFs
Turn photos, scans and images into PDFs, merge and split documents, and export pages to PNG, JPEG, TIFF or plain text.
Sign and certify
Sign with the certificates already in Windows. Time-stamps and long-term validation keep signatures verifiable for years.
Protect and redact
Remove sensitive text and images for good, not just cover them. Encrypt with AES-256 and set exactly what readers may do.
See more of what AJ Pdf can do.
Compare files
Put two versions side by side. AJ Pdf highlights every changed word and every changed pixel, so nothing slips past a review.
Reduce file size
Downsample images, recompress streams and drop duplicates. Smaller files that still look right, ready to mail or upload.
Archive as PDF/A
Validate against PDF/A-2b and convert in one click. Fonts are embedded, colours get an output intent, and the result is checked again.
One price. Pay once, own it.
No subscription, no tiers, no add-ons. Every feature AJ Pdf has is in the licence, and every update for a year joins it.
Full licence
AJ Pdf for Windows
One licence, one PC at a time, yours for good.
€25
one-time
Price includes VAT. Licence key by e-mail. 30-day money-back guarantee.
- Full app, every feature unlocked
- 12 months of updates and new features included
- Keep using the last version you received after that, forever
- Edit text and images, create, merge, split, export
- Digital signatures with time-stamps and long-term validation
- True redaction, AES-256 encryption, OCR
- Compare, compress, PDF/A-2b validate and convert
- E-mail support from the developer
Want another year of updates later? Renew for the same price, only if you want to.
Try it free for 7 days first
The trial is the complete app. Nothing is locked and nothing gets a watermark. No account and no card needed.
- Day 1Download and installRun the installer and open AJ Pdf. The trial starts the first time the app launches.
- Day 1–7Use every featureEdit, sign, redact, archive. Files you save are normal PDFs and stay yours whatever you decide.
- Day 8DecideAJ Pdf switches to viewing, commenting, filling and signing forms, printing and basic organizing. Enter a licence key to unlock everything again. Nothing is charged automatically.
Windows 10 (1809+) or Windows 11, 64-bit or ARM
4 GB RAM
300 MB disk space
Installs per user, no admin rights needed
Your AJ Pdf licence gives you more than great tools.
A real Windows app
Native Direct2D rendering on Windows 10 and 11. Fast scrolling, crisp text, no browser wrapper.
Nothing leaves your PC
No cloud processing and no upload step. Signing, OCR and redaction all run locally.
Built from the spec
Follows ISO 32000-2 (PDF 2.0), PDF/A-2b and PAdES. Lenient with broken files, strict in what it writes.
OCR that is already there
Uses the recognition engine built into Windows, in the languages you have installed. Scans become searchable.
Your certificates, your signatures
Signs with certificates in the Windows store, including smart cards and hardware tokens, and verifies with Windows trust.
Made in Europe
Built in Eindhoven by AI Fellow, signed with a European certificate, downloads served from the EU. Questions reach the person who wrote the code.
Under the hood
An engine we wrote ourselves and test against 1,288 real-world PDFs.
No PDF library, no image library, no font library. Every decoder is our own, and every change is measured against a public test corpus before it ships.
99.46 %
of 1,288 corpus files render every page without error
98.05 %
of convertible files come out clean after PDF/A-2b conversion
6.5 M
glyphs drawn per corpus run, 0.19 % missing
418
unit tests on lexer, filters, fonts, crypto and writer
FlateDecodeLZWJPEG baseline + progressiveJPEG 2000JBIG2CCITT G3/G4TrueTypeCFFType 1Type 3CID fontsShadings 1–7Transparency groupsRC4 / AES-128 / AES-256PAdES B-B / B-T / B-LT / B-LTARFC 3161PDF/A-2bICC colour management
Frequently asked questions
Is it really a one-time payment?
Yes. You pay €25 once and the licence is yours. There is no subscription and nothing renews on its own.
What does "1 year of updates" mean?
For 12 months after purchase, every update and every new feature is included. After that, the version you have keeps working with no time limit. If you want another year of new versions, you can renew at the same price, but you never have to.
Does the free trial include all features?
Yes. For 7 days you get the complete app: editing, signing, redaction, OCR, compare, compression and PDF/A conversion. Nothing is watermarked or locked. No account or payment details are needed to start.
What happens when the trial ends?
AJ Pdf keeps opening, viewing, commenting, filling and signing forms, printing, rotating and deleting pages, and exporting to images, all for free. Editing and the other Pro tools wait for a licence key. Files you edited during the trial are normal PDFs and stay yours.
How does buying work?
Click Buy and pay once. A licence key arrives by e-mail. Paste it into Help › Enter licence key in the app; the key is verified on your PC, no server needed. Not happy? Write within 30 days and you get your money back.
On how many PCs can I use it?
One licence runs on one PC at a time. Moving to a new computer is allowed: deactivate on the old one from the Help menu, or just e-mail us if the old PC is gone.
What are the system requirements?
Windows 10 version 1809 or later, or Windows 11, on a 64-bit or ARM processor. 4 GB RAM, 300 MB disk space. OCR uses the language packs installed in Windows. AJ Pdf brings everything it needs; only the optional File Explorer thumbnails and preview pane need Microsoft’s free .NET Runtime 8 or later installed on the PC, because Explorer cannot use the runtime built into the app. There is no Mac, Linux or mobile version.
Which download do I need, x64 or arm64?
Settings › System › About › System type says "x64-based processor" (take the x64 setup) or "ARM-based processor" (take the arm64 one; the x64 setup also works there, but slower, under emulation).
Does AJ Pdf send my documents anywhere?
No. Rendering, OCR, signing and redaction all happen on your PC. The only network traffic is the update check, and optional time-stamp and revocation requests when you sign, all visible in Settings.
Can I keep using my current PDF reader?
Yes. AJ Pdf does not take over the .pdf file association unless you ask it to in Settings, and it does not uninstall anything. Uninstalling AJ Pdf works through Settings › Apps in Windows.
AJ Pdf for Windows
The complete PDF app. Yours for €25.
Pay once, one year of updates included. Free for the first 7 days.