qfontviewer

A font viewer that uses only minimal Qt dependencies.

qfontviewer is a small, native desktop app for browsing the fonts installed on your system and seeing exactly how they render — including a console / terminal rendering preview that predicts whether glyphs (like the underscore _) get clipped at small pixel sizes, before you commit a font to a real console.

It was written specifically to avoid pulling in a full desktop environment just to look at fonts: it links only qt6-base (Qt 6 Widgets). No GNOME or KDE libraries, no QML runtime, no Python — just one Qt library and a ~150 KB binary.

Why

Most font viewers either belong to a desktop environment (and drag in dozens of its libraries) or render fonts only the way that toolkit draws them. If you live in a tiling-WM / console-centric setup and just want to pick a clean monospace font for your terminal or VT, that's a lot of baggage for a simple question.

qfontviewer answers that question directly, with the smallest possible dependency footprint.

Features

• Font list with live substring filter and a Monospace-only toggle.
• Preview with editable sample text, pixel size, and live size control.
• Console-approximation mode (default) — antialiasing and hinting off, rendered at a chosen pixel size and magnified nearest-neighbor so individual lit pixels are visible, with cell-top / baseline / cell-bottom overlay lines and an objective "_ touches/exceeds cell bottom: yes/no" readout. Flip Antialias on for a normal, faithful desktop preview.
• Glyph grid of the characters a family actually contains (ASCII, Latin, punctuation, arrows, math, box-drawing & block elements), a "go to codepoint" jump (5F, U+2500), and an enlarged detail view.
• Side-by-side compare of two families sharing the same text and size.

The console mode approximates a monochrome single-face console renderer (e.g. kmscon/FreeType): it disables antialiasing, font fallback (NoFontMerging), and subpixel positioning. It predicts clipping reliably but is not byte-identical to any specific console's engine.

Requirements

Runtime	qt6-base (Qt 6 Widgets) — and qt6-wayland if you run Wayland
Build	a C++17 compiler, CMake ≥ 3.21, Ninja or Make

Build & install

From source (CMake)

git clone https://github.com/madalinignisca/qfontviewer.git
cd qfontviewer
cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build build
ctest --test-dir build --output-on-failure   # optional: run the unit tests
sudo cmake --install build                    # default prefix /usr/local

Personal install, no sudo — install under your home directory:

cmake -B build -G Ninja -DCMAKE_INSTALL_PREFIX="$HOME/.local"
cmake --build build
cmake --install build                         # → ~/.local/bin, ~/.local/share/...

See BUILDING.md for options (BUILD_TESTING, prefixes) and the linter/CI commands.

Packages

Ready-made packaging lives under packaging/:

• Arch Linux (AUR) — packaging/aur/ (qfontviewer and qfontviewer-git)
• Debian/Ubuntu — packaging/debian/
• Fedora — packaging/fedora/qfontviewer.spec

See packaging/README.md for per-distro build instructions.

Usage

Launch qfontviewer (it installs a .desktop entry, so it also shows up in app launchers / wmenu). Pick a font on the left; the Preview tab shows it, the Glyphs tab lists its glyphs. To check a console font: select it, set a small pixel size with Antialias off, and watch whether the _ crosses the red cell-bottom line.

qfontviewer --version / --help print the version and usage. The Wayland app_id is io.github.madalinignisca.qfontviewer, so tiling-WM users can target it directly (e.g. in Sway: for_window [app_id="io.github.madalinignisca.qfontviewer"] floating enable). The UI is translatable (Qt Linguist; a Romanian starter translation ships embedded).

Contributing

Issues and pull requests are welcome. The codebase is deliberately small and plain Qt6 Widgets C++17 — no extra dependencies, please, to keep the "minimal" promise. See CONTRIBUTING.md for the workflow (build/test/pre-commit), the Code of Conduct, and SECURITY.md for reporting vulnerabilities. Build/linting details are in BUILDING.md; CI runs tests, pre-commit (clang-format), reuse lint, and clang-tidy/clazy/cppcheck. The project is REUSE-compliant.

License

Licensed under the GNU General Public License v3.0 or later (GPL-3.0-or-later) — the license Qt applications such as Qt Creator use. (The Qt libraries are offered under the LGPL, whose extra permissions exist so software can link them; this is an application, so it carries the full GPL.) The complete text is in COPYING.

Copyright © 2026 Madalin Ignisca <git@madalin.me>