Legacy CSS Compatibility Diff
Compare CSS before and after browser-prefix changes. Inspect added and removed declarations for your chosen browser targets.
Which CSS declarations change for older browsers?
Choose the browser versions you need and select Compare CSS. The report shows declarations added or removed by Autoprefixer, plus a line-by-line comparison. Review both source files before using the output on your website.
Your result
A little clarity, right here.
Start with your own content or load the example. Your result will appear here.
Three simple steps
How to use Legacy CSS Compatibility Diff
Paste your source or open a text file. Try the example if you are learning.
Choose the options and run the tool. Your source stays on this device.
Review the result, then copy it or download the files.
Common questions
Good to know
Understand the result.
Keep the original.
Is this tool free, and are my files uploaded?
This tool is free with no account required. The work happens in your browser. Your input and files are not sent to a processing server.
What are the limits and details?
Up to 100,000 UTF-8 bytes, 5,000 CSS statements and 40 nesting levels. Processing stops after 30 seconds. Files stay on your device. CSS is never applied to this page and JavaScript is never executed. Reports prefix changes only, not all browser incompatibilities. It cannot add missing browser features. A removed prefix may be unnecessary for the selected targets. Support data is bundled with this release.
100 KB of source. Local processing. Cancel at any time.