Bizmuth runs in your browser
October 4, 2026
Bizmuth
Bizmuth Bizmuth now runs in your browser. Try it online: press a machine’s button and it boots.
It is the same emulator as the desktop app, compiled to WebAssembly, laid out like the desktop window with its menus, toolbar and status bar. Every machine is there: the 16K, 48K, 128K, +2A, +3 and the ZX Spectrum Next, which boots NextZXOS from a card image the page supplies.
- Keyboard — click the display, then type. Shift is Caps Shift and Control is Symbol Shift.
- Arrow keys — Sinclair joystick, Cursor Keys, Kempston joystick or Next menu navigation, from the Input menu.
- Gamepads — read as a Kempston joystick.
It runs in desktop Chrome and Safari and needs an internet connection to start. Anything written to the Next’s card lasts for the session only. The debugger, scripting and loading your own files are desktop features for now, so for development work download Bizmuth instead.
Feedback is welcome on the TwistedRaven Discord.