Sioyek

Sioyek is a PDF viewer optimized for navigating technical books and research papers. It offers fast searching across previously opened files, table of contents, bookmarks, and highlights, and can generate a table of contents when none is present. The viewer supports “smart jump” functionality, allowing users to preview or jump to references such as bibliography entries, figures, equations, or even perform a one‑click Google Scholar search, even without embedded links.

The interface emphasizes keyboard‑driven workflow while still supporting mouse actions. Users can place one‑character marks or descriptive bookmarks for quick navigation, highlight text in multiple colors that are searchable, and use a visual ruler to reduce eye strain. A command palette provides searchable access to all shortcuts and commands. Sioyek also integrates with LaTeX via Synctex, automatically reloading documents and enabling one‑click jumps between source and PDF.

Customization is extensive: all keybindings and behaviors can be altered, and external scripts can extend functionality with features such as OCR, translation, or text‑to‑speech. The application runs on macOS and is released as a stable product.