snes9x web

What this app does with your data

By default, everything happens entirely in your browser: ROM files and save states you load are stored locally via IndexedDB, and nothing is sent anywhere. No accounts, no analytics, no tracking, no ads.

Cloud sync is opt-in. If you choose to sign in (an email "magic link", no password), your save-state and ROM data is stored in a Supabase-backed database and file storage under your account only — access is restricted so no other user can read or write it. Your email address is used solely to authenticate you; it is not shared, sold, or used for marketing. You can stop syncing at any time by signing out; data already stored locally in your browser is unaffected either way.

ROMs

This app does not include, host, link to, or distribute any game ROM files. You are responsible for only loading ROM images you already legally own. A game you load is stored only in your own browser (and, only if you opt into cloud sync, your own private cloud storage) — it is never uploaded anywhere else or made visible to anyone else.

Software licensing

This project's own frontend code (the UI, input handling, storage, and the small C shim that wires the emulator core into it) has no separate license file and no explicit grant beyond what's visible in its public source repository. Two vendored, opt-in dependencies carry their own licenses that this app is bound by:

• The emulator core itself is the libretro port of Snes9x, distributed under the Snes9x Licence. That license grants use, copying, modification, and distribution for non-commercial purposes only — commercial use requires separate permission from its copyright holders. It is provided "as-is", with no warranty of any kind.
• The optional "Advanced video (WebGL)" filters vendor real shader source from libretro/glsl-shaders. Two of the four (xBRZ, SABR) are GPL-licensed (GPLv3 and GPLv2-or-later respectively), not MIT — see this project's shader vendoring notes for the full per-file breakdown.

Full details, including exactly what's vendored and from where, are in the project README and CLAUDE.md.

No warranty

This app is provided "as is", without warranty of any kind, express or implied. Save-state and save-data loss, sync conflicts, or other data loss can happen — don't rely on it as your only copy of something irreplaceable.