Photo to FEN

Photo to FEN

Convert a real board photo into a standard FEN by fixing the board corners and matching pieces with templates.

The goal of the first version is not to solve every difficult photo. It is to turn a chessboard photo into an analyzable position quickly. This MVP uses manual corner correction and template matching so you can get to FEN, then continue into review and analysis.

Sachess Editorial Team · 2026-06-20 · 3 sources
Open Sachess Analysis

Highlights

  • Upload an image and drag the four corners to frame the board.
  • The board is rectified, then the 90 intersections are checked.
  • The result can be turned into FEN and corrected in the editor.
  • Good for phone photos, chat screenshots, and over-the-board games.
01

Upload a clear board photo and try to keep the whole board in frame.

02

Drag the four corner points to line up the real board border, then choose the side to move.

03

Run recognition so the app can match templates at each intersection and generate a starter FEN.

04

If a few pieces are wrong, open the board editor, fix them, and continue to analysis.

FAQ

Do I need a cloud AI API
No. The first version keeps geometry correction and template matching in the browser, which keeps costs low.
What if recognition is wrong
Open the board editor, correct the position manually, and continue with the corrected FEN.
Can it read any photo
The first version works best on clear board photos with the board mostly in frame and a reasonable viewing angle.
What happens after recognition
First confirm whose turn it is, then open the analysis page to inspect engine and cloud-book suggestions.

Sources

OpenCV.js intro OpenCV geometry transforms OpenCV template matching

Related Pages

Position Editor FEN Tool AI Analysis FEN Guide