Bitmap Font Editor

Free plan LinuxMacWindows

What Bitmap Font Editor is

Bitmap Font Editor is a free desktop application for making monochrome bitmap fonts, aimed at retro computers and embedded targets, particularly the SAM Coupe. It supports both fixed-width and variable-width fonts, with an adjustable advance width for each glyph. Glyphs can be drawn in cells up to 32×32 pixels by clicking or dragging to paint and erase. Editing tools include undo, redo, copy, paste, clear, invert, flip, and shift. An editable sample text preview is available at three zoom levels, in white-on-black or black-on-white. Raw font bitmap import lets users set the starting codepoint, geometry, and byte layout. Projects use the .fnt.json format, which the project describes as lossless. Export creates a 1bpp bitmap and JSON sidecar files for widths and character mapping. Release 0.1.3 provides Windows, Intel and Apple Silicon macOS, and Linux builds, with SHA-256 checksums. The source is under the MIT license. Windows and macOS builds are unsigned, and filling glyphs from a system font is disabled because Canvas 2D lacks real TrueType hinting.

Who it suits

It suits people creating bitmap fonts for retro home computers or embedded targets. The maker notes that macOS and Linux paths should work but are not regularly exercised.

What it does well

Free desktop editor for Linux, macOS, and Windows.
Supports fixed-width and variable-width fonts.
Exports bitmap data with JSON mapping files.
Release downloads include SHA-256 checksums.

What to know first

Windows and macOS builds are unsigned.
System-font glyph filling is disabled.
macOS and Linux paths are not regularly exercised.

Limits

There is no paid tier listed; the free editor has system-font filling disabled. Windows and macOS builds are unsigned, and the maker says macOS and Linux paths are not regularly exercised.

Getting started

Open the project's GitHub website.
Choose the release 0.1.3 build for Windows, macOS, or Linux; macOS builds are available for Intel and Apple Silicon.
Check the downloadable build's SHA-256 checksum.
On Windows or macOS, account for the unsigned-build warning when launching; macOS requires removing quarantine after download.
Start a project, or import a raw font bitmap and set its starting codepoint, geometry, and byte layout.

Verdict

Bitmap Font Editor provides focused tools for drawing, previewing, importing, and exporting monochrome fonts. Be prepared for unsigned-build warnings, and note that system-font filling is unavailable.

Questions

Is Bitmap Font Editor free?

Yes. It is listed as free, with a free plan.

Which platforms does it support?

Windows, macOS, and Linux builds are available. Release 0.1.3 includes macOS builds for Intel and Apple Silicon.

What does it export?

It exports a 1bpp bitmap plus JSON sidecar files for glyph widths and character mapping. It does not offer webfont export.

Is it open source?

The repository source is covered by the MIT license.

Who makes Bitmap Font Editor?

The GitHub profile identifies spectecjr as Simon Cooke and lists Seattle, Washington.

Are any features disabled?

Filling glyphs from an installed system font is disabled because Canvas 2D lacks access to real TrueType hinting.

Facts from Bitmap Font Editor's own pages

Disabled feature: Filling glyphs from an installed system font is currently disabled because Canvas 2D lacks TrueType hinting access. · github.com, 7 Oct 2026
Download verification: Release 0.1.3 includes SHA-256 checksums for its downloadable builds. · github.com, 7 Oct 2026
Drawing: Glyphs can be drawn in cells up to 32×32 pixels, with draggable font guides and pinned reference glyphs. · github.com, 7 Oct 2026
Editing tools: The editor includes undo and redo, glyph copy and paste, clear, invert, flip, and shift operations. · github.com, 7 Oct 2026
Export: Font export writes a 1bpp bitmap plus JSON sidecar files for widths and character mapping. · github.com, 7 Oct 2026
File formats: Projects use losslessly round-trippable .fnt.json files, and export produces a bitmap binary plus widths and codepoint mapping JSON files. · github.com, 7 Oct 2026
Font types: It supports variable-width and fixed-width fonts. · github.com, 7 Oct 2026
Font widths: It supports variable and fixed-width fonts, with an adjustable advance width for each glyph. · github.com, 7 Oct 2026
Glyph drawing: Glyphs can be drawn in cells up to 32×32 pixels by clicking or dragging to paint and erase. · github.com, 7 Oct 2026
Import: Raw font bitmap import lets users configure the starting codepoint, geometry, and byte layout. · github.com, 7 Oct 2026
Intended audience: The maker describes the editor as intended for bitmap fonts for old home computers and retro or embedded targets. · github.com, 7 Oct 2026
Intended users: The project describes itself as aimed at old home computers, particularly the SAM Coupe, and retro or embedded targets. · github.com, 7 Oct 2026
License: The repository source is covered by the MIT license. · github.com, 7 Oct 2026
Maker: The GitHub profile identifies spectecjr as Simon Cooke and lists Seattle, WA. · github.com, 7 Oct 2026
Notable limitation: Fill From System Font is disabled because Canvas 2D lacks real TrueType hinting and the small-size results are not good enough. · github.com, 7 Oct 2026
Platform caveat: The maker says macOS and Linux paths should work but are not regularly exercised. · github.com, 7 Oct 2026
Platform downloads: Release 0.1.3 provides Windows, macOS for Intel and Apple Silicon, and Linux builds. · github.com, 7 Oct 2026
Platforms: The project describes Windows, macOS, and Linux packaging targets, and says it was developed and used on Windows 11. · github.com, 7 Oct 2026
Preview: Editable sample text can be previewed at three zoom levels in white-on-black or black-on-white. · github.com, 7 Oct 2026
Purpose: Font Editor is a desktop editor for monochrome bitmap fonts, aimed at retro and embedded targets. · github.com, 7 Oct 2026
Saved projects: Projects use the `.fnt.json` format, which the project describes as lossless. · github.com, 7 Oct 2026
Signing: The maker says builds are not code-signed; Windows may show a SmartScreen warning and macOS requires removing quarantine after download. · github.com, 7 Oct 2026
Unsigned builds: Windows and macOS builds are unsigned, so first run shows a SmartScreen or Gatekeeper warning. · github.com, 7 Oct 2026

Where Bitmap Font Editor stands on Freedom251

Font Design Software#8 of 33