ChessVisor

ChessVisor is a browser-based PGN replay studio. Paste or open a chess game, then step through every legal move on an animated board while keeping the notation, comments, players, and game result in view.

It is built as a .NET 10 Blazor WebAssembly progressive web app, so replaying a game happens entirely in the browser.

Highlights

• Load PGN from pasted notation or a .pgn file (up to 2 MB).
• Replay the main line with animated moves, restart/previous/next/end controls, and 0.5×, 1×, or 2× playback.
• Jump directly to any move from the notation list and flip the board at any time.
• Preserve PGN headers, results, comments, annotations, and custom starting positions defined with SetUp/FEN.
• Validate PGN and show actionable, source-aware errors for illegal moves and malformed notation.
• Use System, Light, or Dark themes; the selection is remembered locally.
• Install it as a PWA where supported.

Keyboard shortcuts: focus the board, then use ←/→ to move backward/forward and Space to play or pause.

Screenshots

Light mode	Dark mode

Run locally

Prerequisites: the .NET 10 SDK.

dotnet restore ChessVisor.slnx
dotnet run --project ChessVisor/ChessVisor.csproj

Open the local URL printed by the development server.

Test and publish

dotnet test ChessVisor.slnx --configuration Release
dotnet publish ChessVisor/ChessVisor.csproj --configuration Release --output publish

The repository includes a GitHub Actions workflow that tests and publishes the app to GitHub Pages when changes are pushed to master.

Project structure

Path	Purpose
ChessVisor/	Blazor WebAssembly UI, chessboard, themes, and PWA assets.
Chess.Core/	Chess rules, FEN handling, and PGN parsing/replay models.
Chess.Core.Tests/	Unit tests for PGN parsing and chess-rule behavior.
Docs/	Project screenshots used in this README.