gbajs3
What it is
gbajs3 is a free, open-source Game Boy Advance emulator that runs in modern browsers without plugins. It offers interchangeable mGBA WebAssembly and gbajs JavaScript cores, so users can choose between them. Both cores support a realtime clock. Controls include remappable keyboard bindings and virtual controls for desktop and mobile, while the project also lists mobile interface support and offline progressive web app support. Fast forward is included. The mGBA core supports save states and cheat codes; the gbajs core provides a surface-level assembly debugger. The project also lists a Go server, Nginx content server, admin interface and PostgreSQL support for self-hosted deployments. Setup uses an environment file and Docker Compose. The default admin password is admin and should be changed after login. GitHub lists no releases, and debugger and server enhancements remain work to do.
For and against
For
- Runs in modern browsers without plugins
- Interchangeable mGBA and gbajs cores
- Remappable keyboard and virtual controls
- Offline progressive web app support
- Free and open source
Against
- Save states and cheats require mGBA
- Debugger is limited to gbajs core
- Self-hosting requires Docker Compose setup
- GitHub releases page lists no releases
The verdict
gbajs3 combines two selectable emulator cores with desktop and mobile controls, offline support and fast forward. Core-specific save, cheat and debugger features, plus self-hosting requirements, are important considerations.
Who it suits
It suits users who want browser-based GBA emulation on desktop or mobile, including people running their own instance. It also fits users needing remappable controls, offline web-app support or core-specific debugging and save features.
Plans and prices
Free
Freely licensed · runs in a modern browser
Read 3 Oct 2026 · github.com
On the record
- Controls
- Features include remappable keyboard bindings and virtual controls for desktop and mobile.github.com · read 3 Oct 2026
- Debugger
- A surface level assembly debugger is available for the gbajs core only.github.com · read 3 Oct 2026
- Downloads
- The GitHub releases page says there are no releases.github.com · read 3 Oct 2026
- Emulation cores
- It supports the mGBA WebAssembly core and the gbajs pure JavaScript core, with interchangeable cores.github.com · read 3 Oct 2026
- Fast forward
- The project includes a fast forward feature.github.com · read 3 Oct 2026
- Intended use
- The maker says the project was driven by a need to play modern GBA ROM hacks outside desktop applications without sideloading or building through Xcode.github.com · read 3 Oct 2026
- Limits and roadmap
- The README lists debugger and server enhancements as work to do and describes S3 backed file storage as a future server enhancement.github.com · read 3 Oct 2026
- Mobile and offline
- The project lists mobile UI support and offline progressive web app support.github.com · read 3 Oct 2026
- Realtime clock
- Both emulator cores support a realtime clock.github.com · read 3 Oct 2026
- Save states and cheats
- Save states and cheat codes are supported by the mGBA core only.github.com · read 3 Oct 2026
- Security setup
- The setup guide says the default admin password is admin and instructs users to change it immediately after logging in.github.com · read 3 Oct 2026
- Self hosting
- The setup instructions say to configure an environment file and start the services with Docker Compose.github.com · read 3 Oct 2026
- Server components
- The feature list includes a Go server for logged in user support, an Nginx server for gbajs3 content, an admin UI, and PostgreSQL support.github.com · read 3 Oct 2026
- What it does
- gbajs3 is a browser based Game Boy Advance emulator that works in modern browsers without plugins.github.com · read 3 Oct 2026
