Sioyek — Research-Focused PDF Viewer for Technical Documents

Introduction

Sioyek is a PDF viewer built specifically for reading research papers, textbooks, and technical documentation. It focuses on keyboard-driven navigation with features like smart jump (click a citation to jump to the reference), portals (view a referenced figure while reading), and hierarchical bookmarks.

What Sioyek Does

• Provides smart jump to follow references, citations, and footnotes within and across PDFs
• Supports portals that let you view a referenced section in a floating window without losing your place
• Offers fast full-text search across all open documents
• Renders PDFs with hardware-accelerated graphics using MuPDF as the backend
• Syncs with LaTeX editors via SyncTeX for forward and inverse search

Architecture Overview

Sioyek is written in C++ using Qt for the UI and MuPDF for PDF rendering. It maintains an SQLite database for bookmarks, highlights, and portals. The smart-jump feature uses heuristics to parse citation patterns and locate target references within the document or linked PDFs. Configuration is done through two plain-text files: keys.config for keybindings and prefs.config for preferences.

Self-Hosting & Configuration

• Available as pre-built binaries for Windows, macOS, and Linux (AppImage and Flathub)
• Customize keybindings in ~/.config/sioyek/keys_user.config
• Set preferences like default dark mode, page layout, and font in prefs_user.config
• Shared database can be synced across machines via cloud storage for portable bookmarks
• Supports custom color schemes for comfortable reading in different lighting

Key Features

• Smart jump parses citations and jumps to the referenced paper or section instantly
• Portal windows show referenced figures, tables, or equations alongside the current page
• Ruler mode highlights the current line to aid reading dense text
• Marks and bookmarks with descriptions for organizing reading sessions
• Command palette with fuzzy search for all actions

Comparison with Similar Tools

• Zathura — Minimal vim-like PDF viewer; lacks smart jump and portal features
• Okular — Feature-rich KDE viewer; heavier and less keyboard-focused
• Evince — GNOME default; simple but no research-specific features
• PDF.js — Browser-based; works everywhere but missing desktop-grade navigation
• SumatraPDF — Fast Windows viewer; no smart jump or portals

FAQ

Q: Does Sioyek support annotations and highlights? A: Yes. You can highlight text and add bookmarks with descriptions. Annotations are stored in a local database.

Q: Can I use Sioyek with LaTeX editors? A: Yes. Sioyek supports SyncTeX for forward and inverse search with editors like VS Code, Neovim, and Emacs.

Q: Is Sioyek open source? A: Yes, Sioyek is released under the GPL-3.0 license.

Q: Does it support dark mode? A: Yes. Sioyek has built-in dark mode with customizable color inversion and custom background colors.

Sources

• https://github.com/ahrm/sioyek
• https://sioyek.info/