About Block Jigsaw
Block Jigsaw is an original browser puzzle project built around one rule: every supplied connected shape must fit into the board until no cell is left empty.
Why this project exists
The aim is to make a puzzle that starts quickly, works directly in a browser and remains interesting after the first few boards. Rather than using one fixed set of levels, the game generates a fresh connected partition of the board for each new puzzle.
The site also documents the mechanics instead of hiding them behind a generic “play now” page. The strategy and generation guides explain what makes the puzzle work, why wrong-but-legal moves are allowed and how difficulty changes between modes.
How the game differs from outline matching
Many drag-and-drop puzzles accept a piece only at its intended target. Block Jigsaw instead checks the geometry of the current board: a move is legal when the transformed piece stays within the grid and does not overlap anything already placed. This means the player can construct alternative arrangements and can also create dead ends.
That choice was deliberate because it preserves planning and backtracking. The player must reason about the remaining empty region rather than simply search for the location that triggers an acceptance animation.
How puzzles are created
The generator begins with a complete square grid. It places several seed cells, then grows connected regions until every grid cell belongs to one region. Attempts with pieces that are too small or excessively large are rejected. The resulting regions are normalized into pieces and then rotated or flipped according to the selected mode.
Because the pieces originate from a complete board, the generated set starts with at least one known arrangement. The hint system can refer back to that original arrangement, while the player remains free to discover a different valid solution.
Read the detailed generator explanation →
Design priorities
Fast access
No account or app installation is required. The game is embedded directly on the home page.
Progressive difficulty
Modes vary board size, piece count, irregularity, rotation, flipping and assistance.
Desktop and touch
The interface supports mouse/trackpad input and mobile touch gestures, with a full-screen option.
Explain the mechanics
The site publishes original guides about the actual code and puzzle design instead of padding pages with unrelated content.
Project status and maintenance
Block Jigsaw is actively maintained. Site improvements are documented on the Updates page, including changes to mobile guidance, content structure, accessibility information and supporting documentation.
Feedback
Bug reports and constructive suggestions are welcome. If a particular browser, screen size or control does not behave correctly, include the device/browser name and a short description of what happened. Do not send sensitive personal information.