Block Poster Maker is a browser-based tool for turning any image into a large printable poster. Users can upload their own JPG, PNG, or WebP image, or start from a ready-made template, then split the design across multiple Letter or A4 pages. The tool supports Fit and Fill image modes, adjustable poster size, page overlap, and print margins, making it easier to assemble a clean multi-page poster at home, in a classroom, or for events. The exported PDF includes an assembly guide page with numbered tiles, so users can quickly understand how the printed sheets should be arranged before taping them together. Images are processed in the browser, with no account required and no server upload needed for the core poster-making workflow. Block Poster Maker is designed for classrooms, birthdays, holidays, photo walls, event signs, and teaching materials. It helps anyone create large posters from ordinary images using a standard home or office printer.