What is Sioyek used for?

Sioyek is a PDF viewer built for textbooks and research papers, with quick file opening, table of contents navigation and installers for major desktop systems. It is a good fit for reading research papers and studying from long textbooks.

Is Sioyek open source?

Yes. Sioyek is open source under the GPL-3.0 licence. Its source code is on GitHub at ahrm/sioyek and is written mainly in C.

Yes. Sioyek is open source, so the software itself is free to use.

Can I self-host Sioyek?

Yes. Sioyek can be self-hosted on your own server or infrastructure.

What is Sioyek an alternative to?

Sioyek is an open-source alternative to Adobe Acrobat and PDF Expert. Other open-source alternatives to Adobe Acrobat include Stirling PDF, BentoPDF and PDFsam.

Is Sioyek actively maintained?

Yes. The most recent commit to Sioyek was on 24 September 2026, and the latest release is v2.0.0, published on 16 December 2022. The project has 9.9k stars on GitHub.

Sioyek: open-source alternative to Adobe Acrobat, PDF Expert

About Sioyek

Sioyek is a PDF viewer with a focus on textbooks and research papers. It is meant for people who read long technical documents and need to move around them quickly, rather than just scroll through pages.

Features documented in the README include quick open, which lets you search for and open any file you have previously used, and navigation through a document's table of contents. The project offers official documentation and a video overview. Installers cover Windows, macOS and Linux, a Homebrew cask is available, and third-party packages exist for Flathub, Alpine, Arch, Debian, NixOS, openSUSE and Ubuntu.

Sioyek is written in C and C++ with Qt and released under GPL-3.0. Building the development branch needs Qt 6.7 or 6.8, and the FAQ explains how to get past the macOS quarantine message. The author accepts support through a buy-me-a-coffee link.

Key features

PDF viewing for books and papers
Quick open for previously used files
Table of contents navigation
Installers for Windows, macOS and Linux
Documentation and video demo

Good fit for

→Reading research papers
→Studying from long textbooks

Built with: C
Tags: pdf-viewer; research; reading; textbooks; desktop-app; qt; cross-platform

Sioyek: questions and answers

What is Sioyek used for?: Sioyek is a PDF viewer built for textbooks and research papers, with quick file opening, table of contents navigation and installers for major desktop systems. It is a good fit for reading research papers and studying from long textbooks.
Is Sioyek open source?: Yes. Sioyek is open source under the GPL-3.0 licence. Its source code is on GitHub at ahrm/sioyek and is written mainly in C.
Is Sioyek free?: Yes. Sioyek is open source, so the software itself is free to use.
Can I self-host Sioyek?: Yes. Sioyek can be self-hosted on your own server or infrastructure.
What is Sioyek an alternative to?: Sioyek is an open-source alternative to Adobe Acrobat and PDF Expert. Other open-source alternatives to Adobe Acrobat include Stirling PDF, BentoPDF and PDFsam.
Is Sioyek actively maintained?: Yes. The most recent commit to Sioyek was on 24 September 2026, and the latest release is v2.0.0, published on 16 December 2022. The project has 9.9k stars on GitHub.