Software licenses

Stockfish.js 19

Computer chess uses the unmodified lite single-thread build of Stockfish.js, distributed under GPLv3. The engine runs in a separate Web Worker and loads when you choose computer play.

Read the GPLv3 license · Source code and build instructions

Other libraries

chess.js (BSD-2-Clause), React, TanStack, Hono, Better Auth and Colyseus (MIT), Dexie and Drizzle (Apache-2.0). Inter uses the SIL Open Font License. The full inventory is available in the project's THIRD_PARTY_LICENSES.md.