Sioyek is a PDF viewer with a focus on textbooks and research papers

Original Article ↗ Hacker News Discussion ↗

Overall reception

  • Many commenters are enthusiastic; several call Sioyek their primary or “best” PDF viewer for research.
  • Appreciated especially by users who like keyboard- and Vim-style navigation and research-focused workflows.
  • Some users still prefer other tools due to bugs, missing features, or ecosystem fit.

Notable features

  • Vim-like navigation (gg/G, command palette) and command-based UI are widely praised.
  • Visual line-highlighting (“visual mark” / ruler) and dark/solarized modes are cited as major reductions in eye strain.
  • Heuristic table-of-contents generation for PDFs without TOC is considered useful, though more reliable for papers than math-heavy textbooks.
  • Separate storage of annotations is seen as beneficial by some (clean PDFs, potential for standardized annotation formats), with an option to embed annotations into a new PDF.

Limitations and pain points

  • Plugin/extension installation is described as complex; some features (e.g., two-column viewing) were originally only via extensions.
  • Some users report crashes or inability to open multiple PDFs easily; others say recent versions mitigate this via settings/flags.
  • No bulk import or robust “open directory” handling, especially for large collections or cloud drives.
  • Windows 7 is not supported, which caused confusion about system requirements.
  • Some find the lack of traditional menus/help screens inconvenient.

Development status and roadmap

  • Initial concern about abandonment is countered by multiple references to an active development branch and even a private branch.
  • Newer/coming features (mostly in development): native two-panel and 2-page modes, simpler JavaScript extensions, possible ~/.config support, multi-window support, Android port; iOS port is reportedly more difficult.

Annotations, notes, and ecosystem integration

  • Debate over embedding annotations vs. external files; some want both for interoperability with other viewers and tools (Zotero, Obsidian, KOReader).
  • Broader discussion of research workflows: desire to integrate reading, annotation, note-taking, and long-term knowledge management without lock-in.
  • Several external tools are mentioned (knowledge bases, web annotation, collaborative readers) as complementary or aspirational integrations.

Mobile, e‑ink, and alternatives

  • Thread includes many recommendations for iPad and mobile PDF readers and e‑ink devices, reflecting a strong demand for Sioyek-like features on tablets.
  • Readers want features like single-column reflow, LLM-based semantic search, multi-format support, and easy export of highlights (e.g., to markdown).