Unlock the full potential of your chess game with our advanced analysis tools.
Choose the plan that fits your journey.
Everything you need to know about ReThink.fast
The Free plan grants you full access to the entire application—identical to the Premium version—so you can thoroughly test every feature. The only constraint is the 15-minute active analysis timer, which resets daily at midnight UTC. It includes 3 Daily Puzzles and full engine power.
Unlimited plans include unrestricted access to all features: game analysis, Rainbow Mode visualization, human-like AI opponents, opening history, puzzle solving, and instant mistake explanations. No time limits, no restrictions.
Brilliant Puzzles are handpicked, high-quality tactical challenges that focus on critical game moments. We don’t just ask you to find the move — the challenge is to prove the move’s superiority by finding the key variations that justify it. Additionally, instant engine evaluation and color-coded visualization are shown when a mistake is made. Our database contains 1500 Brilliant Puzzles across all difficulty levels (often sourced from real master games), perfect for structured improvement!
Yes! You can import games using PGN or FEN format from any chess platform including Chess.com, Lichess, or any other site. Just copy the game notation and paste it into our import tool.
Yes! ReThink.fast is fully responsive and works on tablets and smartphones via your browser. We don't have dedicated mobile apps yet, but the web version is optimized for touch interfaces. For the best experience with detailed analysis and Rainbow Mode visualization, we recommend using a laptop or desktop computer.
It's not just a standard engine. ReThink.fast orchestrates multiple parallel instances of Stockfish (via WebAssembly) to calculate variations simultaneously with different settings. Our proprietary Context Analyzer doesn't just read scores; it "translates" chess logic—detecting pins, skewers, forks, and initiative—to generate natural language explanations. We even verify critical lines with separate worker threads to prove the best move against all defenses.
Absolutely. ReThink.fast is a passion project born from a lifelong love for chess, not just a random business decision. I have a roadmap filled with innovative features and deep analysis tools that I can't wait to build. This project will continue to evolve because I'm building the tool I've always wanted as a player. I'm also listening—if you have ideas or feedback, reach out on social media or at rethink.fast@gmail.com. Let's build the ultimate chess companion together.
Experience chess analysis like never before
A visual way to intuitively understand why some moves are simply better than others. Colors guide you to the best decisions, while customizable depth ensures instant feedback.
A workflow found nowhere else. Drag & drop any screenshot of a chessboard directly onto the app to instantly load the position. Analyze, edit, and play in seconds. Or import directly from Lichess/Chess.com.
Click any individual piece to see its specific evaluation. Play as the opponent to test responses, or let the engine show you how a weaker player might react.
Powered by Maia, a neural network that predicts human moves. Dynamically adjust difficulty to simulate realistic opponents—no more robotic, unnatural engine play.
Every move comes with a description that describes the reality of the board. Our Context Analyzer explains pins, threats, and tactics in plain language.
4,800+ positions represent pre-cached knowledge for instant delivery. Always capable of deeper calculation—you define the engine depth.
A visually stunning interface where everything is configurable. Adjust hint colors, board themes, and UI elements to match your style perfectly.
You decide how much help you need. Freely undo moves, change historical decisions, and customize hint levels to challenge yourself on your own terms.
Designed for speed. Use comprehensive keyboard shortcuts to navigate games, flip the board, and toggle tools without lifting your hands.
High-quality puzzles with hints pre-calculated to Depth 20. Structured improvement that helps you recognize tactical patterns in real game situations.