Check if JPEG images are progressive
Can be useful to make sure your images are progressive, which is important for performance:
Progressive JPEGs are better because they are faster. Appearing faster is being faster, and perceived speed is more important that actual speed. - Progressive JPEGs: a new best practice
The check is fast as it only reads a small part of the file.
$ npm install --global is-progressive-cli
$ is-progressive --help Usage $ is-progressive <file> ... $ is-progressive < <file> Example $ is-progressive baseline.jpg progressive.jpg ✖ baseline.jpg ✔ progressive.jpg
You can use globs too if your shell supports that.
$ is-progressive *.jpg
- is-progressive - API for this module
MIT © Sindre Sorhus