# Compatibility Panel
## Related files
The compatibility panel consists of the following files:
* Client:
* Main: `devtools/client/inspector/compatibility/`
* Style: `devtools/client/themes/compatibility.css`
* Shared:
* MDN compatibility dataset: `devtools/shared/compatibility/dataset/`
* MDN compatibility library: `devtools/server/actors/compatibility/lib/MDNCompatibil
ity.js`
* User setting file - `devtools/shared/compatibility/compatibility-user-settings.js`
* Server:
* Actor: `devtools/server/actors/compatibility.js`
* Front: `devtools/client/fronts/compatibility.js`
* Spec: `devtools/shared/specs/compatibility.js`
## MDN Compatibility Data
The Compatibility panel detects issues by comparing against official [MDN compatibility data](https://github.com/mdn/browser-compat-data). It uses a local snapshot of the dataset. This dataset needs to be manually synchronized periodically to `devtools/shared/compatibility/dataset` (ideally with every Firefox release).
To update this dataset, please refer to the guidelines in `devtools/shared/compatibility/README.md`
## Tests
* Client: `devtools/client/inspector/compatibility/test`
* MDN compatibility library: `devtools/server/actors/compatibility/lib/test`
* Server: `devtools/server/tests/browser/browser_compatibility_cssIssues.js`
