Yes, runs mGBA WASM locally in browser, no download.

Is GBA Emulator Legal? Is EggerMath Safe?

Emulators are legal. ROMs are legal only if you own the game.

Emulator = Legal, ROM = Own Your Game

Emulators like mGBA are legal (like a media player). Downloading ROMs you don't own may violate copyright. Use your own dumps or public domain ROMs.

Yes — runs entirely in your browser via WebAssembly, no executable download. Saves stay in your browser storage. See Privacy and DMCA.