blundermate Lab
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Chess Image OCR

Drop a 2D board screenshot and turn it into FEN with your local OCR server.

Setup

Local server required

This Lab page is static. The board image is sent to a local Python OCR server running on your PC.

Download local server 2d-chess-ocr source
  1. Install the upstream 2d-chess-ocr repo and download its finetuned model.
  2. Unzip the local server package next to that repo, or set CHESS_OCR_ROOT.
  3. Run .\start.ps1 and keep http://127.0.0.1:8765 open.

Server

Local OCR endpoint

Change this only if you run the Python server on another port.

Open local app

Input

Board screenshot

Use a clean 2D board crop for the best FEN.

Drop an image to see the detected board and FEN.

Output

Recognition result

Detected boards, confidence, and copyable FEN stay here.