GSE

GSE is an emulator for Game Boy, Game Boy Color and Game Boy Advance, built around the needs of speedrunners. It is best suited to runners who prioritize repeatable timing and verifiable inputs. Its focused toolkit is a strong fit for that work, though BIOS requirements and omitted cheat support narrow its appeal beyond it.

Overview

GSE uses Gambatte for Game Boy and Game Boy Color, and Mesen’s core for Game Boy Advance. Its older-system emulation is geared toward speedrunning, while the GBA core targets console accuracy. That distinction matters to runners choosing a system: GSE’s stated GBA goal is accuracy, while its Game Boy and Color emphasis is tested performance for runs.

GSE requires bootrom or BIOS files, so it is not the simplest option for someone who expects to install an emulator and launch a game immediately. The project is distributed under the Mozilla Public License 2.0, and the software is provided as-is without warranty.

Key features

GSE runs at approximately 59.7275 FPS and uses clock synchronization for consistent frame pacing and low input lag. Optional Low Latency Mode can reduce input lag further, but may make frame pacing less consistent. The standard mode is the more measured choice for runners who value repeatability; the optional mode trades some consistency for responsiveness.

Input logs are saved for all runs, giving verifiers a secondary source of proof. That makes GSE more compelling for verification-conscious runners than an emulator whose run evidence is limited to the gameplay result alone.

There are 100 savestate slots, organized into 10 sets of 10, which gives practice sessions room for multiple checkpoints. ROMs can be opened from 7z, rar, tar, gz and zip archives. Controller support runs through SDL3 and includes the official GameCube USB Adapter and Switch controllers, a useful range for runners with established controller setups. Discord Rich Presence is also available, but is off by default.

Input mapping has firm boundaries: different game inputs cannot share one host input, and Left+Right or Up+Down combinations are prohibited. Those rules constrain unusual setups but avoid those specific input combinations. Cheat-code support is absent, along with features considered outside the needs of speedrunning and practice, so players who rely on cheats should choose another emulator.

Pricing

GSE is free, with no paid plans or tier trade-offs described. Its free price does not remove the practical requirement for bootrom or BIOS files. The v0.6 release provides downloads for multiple operating systems and CPU architectures; GSE-win-x64.zip is recommended for most Windows x64 users.

Platforms

GSE supports Windows, macOS, Linux and Android, covering desktop and mobile use. Requirements are Windows 7 SP1 or later, macOS 10.15 or later, Linux with glibc 2.31 or libstdc++ 3.4.28 or later, and Android 5.0 or later. Check those minimums before choosing it for an older system, particularly on Linux, where the library versions are part of the requirement.

Who it's for

GSE is the clearest fit for Game Boy, Game Boy Color and Game Boy Advance runners who want synchronized timing, stored input logs and numerous savestate slots. Its controller breadth and archive support also serve runners with varied hardware and ROM packaging. It is less suitable for casual players seeking cheat codes or a setup without a bootrom or BIOS requirement.

Pros and cons

Pros

Clock synchronization and approximately 59.7275 FPS support consistent timing for speedrunning.

Input logs are retained for every run, providing an additional verification record.

One hundred savestate slots and SDL3 controller support, including GameCube USB Adapter and Switch controllers, support varied practice setups.

Free software across Windows, macOS, Linux and Android makes it usable across desktop and mobile systems.

Cons

Bootrom or BIOS files are required, adding a prerequisite before use.

No cheat-code support makes it a poor choice for players whose practice or play depends on cheats.

Low Latency Mode may reduce frame-pacing consistency, so lower input lag comes with a meaningful trade-off.

Input-sharing and opposing-direction combinations are blocked, limiting some custom input arrangements.

The MPL-2.0 license provides the software as-is without warranty.

Alternatives

For a broader comparison of GBA emulators, see Game Boy Advance Emulators. Choose among emulators there if GSE’s speedrunning focus or BIOS requirement does not fit your needs.

Verdict

Choose GSE if you run Game Boy, Game Boy Color or Game Boy Advance games and value consistent timing, input-log verification and generous savestate support in a free emulator. Look elsewhere if you need cheat codes or want to avoid the bootrom or BIOS prerequisite.