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Life & fun · January 9, 2025

TI

Tetris in a PDF

I realized that the PDF engines of modern desktop browsers (PDFium and PDF.js) support JavaScript with enough I/O primitives to make a basic game like Tetris. It was a bit tricky to find a union of features that work in both engines, but in the end it turns out that showing/hiding annotation "fields" works well to make monochrome pixels, and keyboard input can be achieved by typing in a text input box. All in all it's quite janky but a nice reminder of how general purpose PDF scripting can be. The linked PDF is all ASCII so you can just open it in a text editor, or have a look at…

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In plain words

Tetris in a PDF is a playable implementation of Tetris built entirely within a PDF file using JavaScript supported by modern browser PDF engines. It works by using annotation fields to create monochrome pixels and a text input box for keyboard controls. The game is fully viewable as ASCII text in any text editor, demonstrating how PDF scripting can support interactive applications despite technical limitations across different PDF engines.

written from the facts on this page · September 2026

From the sources

In the maker’s words, at launch

I realized that the PDF engines of modern desktop browsers (PDFium and PDF.js) support JavaScript with enough I/O primitives to make a basic game like Tetris. It was a bit tricky to find a union of features that work in both engines, but in the end it turns out that showing/hiding annotation "fields" works well to make monochrome pixels, and keyboard input can be achieved by typing in a text input box. All in all it's quite janky but a nice reminder of how general purpose PDF scripting can be. The linked PDF is all ASCII so you can just open it in a text editor, or have a look at the source code here: https://github.com/ThomasRinsma/pdftris/blob/main/gengrid.py

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