Imagine finishing a game on Chess.com. Usually, you would rely on the site's "Game Review" feature (which may be paywalled or limited). With the right userscript, you can instantly have a Stockfish analysis depth 20+ running in
When you visit a website (e.g., chess.com/game/live ), Tampermonkey checks its library of installed scripts. If the URL matches a script’s settings, the script runs automatically, injecting new code into the page. This can alter the DOM (Document Object Model)—adding buttons, changing colors, hiding elements, or even reading the chess board’s state. tampermonkey chess script
If you want to test openings, use Lichess’s or Stockfish in a separate window . If you want to practice, play against a low-strength bot. Imagine finishing a game on Chess
. By "reading" the positions of pieces from the page’s code, a script can export data to external chess engines like Stockfish. This bridge between the visual game and a grandmaster-level engine is the core mechanism behind most chess-related userscripts. Enhancements vs. Exploits If the URL matches a script’s settings, the
Online chess websites are built on standard HTML5 and JavaScript. The board coordinates, piece positions, move lists, and clocks are all accessible via code. A well-crafted Tampermonkey script can read this data instantly.