PDF4QT
What PDF4QT is
PDF4QT is a free, open-source PDF toolkit for Windows and Linux. It combines desktop applications, command-line tools and a C++/Qt PDF engine. The suite includes a viewer, document page organizer and document comparison tool. Listed PDF functions cover text editing, annotations, form filling, redaction, document signing, attachment management, compression, encryption and digital-signature validation. A command-line utility supports script integration, and the project lists multithreaded and hardware-accelerated rendering. Its PDF functionality is based on PDF Reference 2.0. Static XFA support is read-only and limited to simple XFA. Windows downloads include installer and ZIP options; Linux packages include AppImage and Flatpak, while the historical .deb package was discontinued. The repository says it was relicensed under MIT on April 27, 2025, with separate requirements for third-party components, and provides the software without warranty.
Who it suits
PDF4QT suits Windows or Linux users seeking a free desktop toolkit for editing, annotating, converting and organizing PDFs. Developers can also use its command-line tool for scripts.
What it does well
- Free and open-source toolkit
- Supports Windows and Linux
- Includes annotations, redaction and signing
- Command-line tool supports script integration
- Encryption and signature validation listed
What to know first
- No OCR listed
- No form creation listed
- Static XFA support is limited and read-only
- Software is provided without warranty
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| PDF4QT | Open-source PDF toolkit · Windows and Linux · No warranty | Free |
As github.com lists them, read 11 Oct 2026. The maker's own page has the final word.
Verdict
PDF4QT covers many desktop PDF tasks and adds command-line access for automation. Its lack of OCR and form creation, plus limited XFA support, may matter for specialized documents.
Facts from PDF4QT's own pages
- Annotation tools
- Yes · github.com, 20 Sept 2026
- Applications
- The suite includes PDF viewing, document page manipulation, and document comparison applications. · github.com, 11 Oct 2026
- Command-line use
- PDF4QT includes a command-line tool, which the project describes as useful for script integration. · jakubmelka.github.io, 11 Oct 2026
- Developer use
- The project can be compiled on Windows and Linux and requires a compiler supporting C++20. · github.com, 11 Oct 2026
- Document security
- The project lists encryption and digital signature validation among its features. · github.com, 11 Oct 2026
- Downloads
- The project lists Windows installer and ZIP downloads, plus Linux AppImage and Flatpak packages. · jakubmelka.github.io, 11 Oct 2026
- Form creation
- No · github.com, 20 Sept 2026
- Free plan
- Yes · github.com, 20 Sept 2026
- License
- The repository says PDF4QT is licensed under the MIT License. · github.com, 11 Oct 2026
- Linux downloads
- The README lists Flatpak and AppImage packages for Linux, and says the historical .deb package was discontinued. · github.com, 11 Oct 2026
- Maintainer
- The README says the software is written and maintained by Jakub Melka. · github.com, 11 Oct 2026
- OCR
- OCR for scanned documents uses Tesseract and can add a searchable invisible text layer. · github.com, 11 Oct 2026
- PDF applications
- Its applications include a viewer, a document page organizer, and a tool for comparing two documents. · jakubmelka.github.io, 11 Oct 2026
- PDF conversion
- Yes · github.com, 20 Sept 2026
- PDF editing
- Listed features include annotations, form filling, redaction, document signing, and managing file attachments. · jakubmelka.github.io, 11 Oct 2026
- PDF features
- Listed capabilities include encryption, signature validation, annotations, form filling, document editing, compression, and digital signing. · github.com, 11 Oct 2026
- PDF standard
- The project says its PDF functionality is based on PDF Reference 2.0. · github.com, 11 Oct 2026
- Product
- PDF4QT is an open-source PDF toolkit with desktop applications, command-line tools, and a C++/Qt PDF engine. · github.com, 11 Oct 2026
- Purpose
- PDF4QT is an open-source PDF toolkit with desktop applications, command-line tools, and a C++/Qt PDF engine. · github.com, 11 Oct 2026
- Rendering
- The project lists multithreading and hardware-accelerated rendering among its features. · jakubmelka.github.io, 11 Oct 2026
- Security policy
- GitHub reports that the project has no SECURITY.md policy and no published security advisories. · github.com, 11 Oct 2026
- Supported platforms
- Windows,Linux · github.com, 20 Sept 2026
- Text editing
- Yes · github.com, 20 Sept 2026
- Warranty
- The software is provided without any warranty. · github.com, 11 Oct 2026
Where PDF4QT stands on Freedom251
- PDF editors#59 of 102