Open Site Review
Compatibility and front-end practice scanner for HTML, CSS, and JavaScript.
What it does
- Checks whether you are using features that are too new for your target browsers.
- Identifies polyfills that are no longer needed.
- Highlights native web platform features that can replace JavaScript.
Submit a scan
Enter a short site name and the URLs you want reviewed (one per line). Clicking Open issue on GitHub will take you to GitHub with the issue pre-filled — just click Submit new issue there to queue the scan.
How it works
Submitting the form opens a pre-filled issue in the
open-site-review repository.
Any issue whose title begins with SCAN: is picked up automatically by the
CI workflow, which runs the scan, posts the report as a comment, and publishes it here.
Learn more
The Web Almanac by HTTP Archive tracks real-world web feature adoption at scale. The 2024 Markup and 2022 CSS (most recent published) chapters provide useful context for understanding which features are commonly used in the wild and where compatibility trade-offs matter most.