Block Poster turns a single image into a huge printed poster — sliced across ordinary sheets, assembled at home, and processed entirely in your browser.
A wall-sized print used to mean a trip to a print shop and a price to match. But almost everyone already owns a printer that handles A4 or Letter paper. The only missing piece was a tool that could cut one big picture into pages small enough to print, then put them back together on the wall.
Most converters that claim to do this want your file uploaded to a server first. We went the other way: the image is read into memory, sliced on a canvas, and written into a PDF by your own browser. Nothing is uploaded, nothing is stored, and there is no account to create.
A4, A3 and US Letter, portrait or landscape, with printer margins and overlap handled for you.
Open the page and start right away. Your image never leaves your device, so there is nothing to wait for.
See the page grid, the coordinate chips and the overlap bands update as you change the layout.
A specification sheet plus one numbered page per tile, exported at up to 300 DPI.
Any modern browser on desktop or phone. Nothing to install, nothing to configure.
No accounts, no image storage, and no telemetry about the pictures you use.
Pick a paper size and a grid, and Block Poster divides the poster area into pages. Each page is drawn to a canvas at your chosen DPI, clipped to its own slice of the image, and stamped with a row and column coordinate so the sheets can be matched up later.
The same geometry drives the on-screen preview and the exported PDF, so the grid you configure is the grid you print. The whole loop — reading, slicing and encoding — happens on your device; the page's only network traffic is its own assets, fonts and analytics.