In simple English
This tool compares two image files and highlights the differences between them. It runs in milliseconds, even on large screenshots. You can use it in your terminal, inside your Node.js code, or with browser testing tools. It saves time when you run automated tests that take screenshots of websites. The software is free to use and open source.
What it is
Odiff is an image comparison library written in the Zig programming language. It uses low-level hardware optimizations to speed up pixel matching across different image formats.
What it is good for
Solo builders who need to check visual regression in web apps or compare generated images without slowing down their test pipeline.
- Compares different image formats like PNG, JPEG, and WebP against each other.
- Runs much faster than traditional image comparison tools.
- Includes a persistent server mode to avoid startup delays in automated tests.
- Requires familiarity with the command line or Node.js to set up.
- Produces a visual diff file only when actual pixel differences are found.
- Needs enough processor support for hardware vector instructions to reach top speed.
pixelmatch
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npm install odiff-bin odiff --help