Chess4D

Chess4D is a free browser chess site with three modes. 4D Chess lets you move pieces across a four-dimensional hypercube board, with legal-move markers and rules for how each piece moves in 4D. 3D Chess is standard 8x8 chess shown in a full 3D view: play against Stockfish, analyze moves, or play two-player on one device. 5D Chess is an experimental time-travel variant with branching timelines, local two-player play and replay. Tutorials and guided lessons cover all three modes. Everything runs in the browser in English or Chinese, with no download or account needed. There is no online matchmaking.