CSS Sentry
Browser extension for detecting and reducing CSS-based data exfiltration risk.
As of June 2026, CSS Sentry has 34 users in the Privacy & Security category.
Usersno change0%
34
34
Ratingno change0%
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— reviews
Reviewsno change0%
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Version
1.0.86
Manifest V3
90-day change · In the last 90 days this extension 3 version updates, changed permissions.
History
5 snapshotsTracking since May 3, 2026.
Not enough history yet for this metric — the chart fills in as we collect more snapshots.
View as table
| Date | Users | Rating | Reviews | Version |
|---|---|---|---|---|
| May 3, 2026 | — | — | — | 1.0.11 |
| May 9, 2026 | — | — | — | 1.0.11 |
| May 14, 2026 | — | — | — | 1.0.21 |
| May 20, 2026 | — | — | — | 1.0.34 |
| Jun 8, 2026 | — | — | — | 1.0.86 |
| Now | 34 | — | — | 1.0.86 |
Changelog
- May 20, 2026permissions
storage, declarativeNetRequest, webNavigation, webRequest
storage, declarativeNetRequest, webNavigation
Permissions & access
- Permissions
- storagedeclarativeNetRequestwebNavigation
- Host access
- <all_urls>
Screenshots
About
CSS Sentry is a local-only browser extension that helps detect and reduce risk from CSS-based data exfiltration techniques. It analyzes page styles for suspicious selector probing, remote CSS resource sinks, CSS imports, SVG/CSS resource behavior, data stylesheets, and rendered-content CSS injection patterns. The extension is designed as a defense-in-depth tool. It includes Passive, Balanced, and Strict protection modes, local reports, destination allow/block policy support, advanced compatibility options, and optional Firefox-specific enhanced stylesheet inspection. CSS Sentry does not use telemetry, cloud analysis, or a remote service. Reports are stored locally in your browser. This extension does not claim to prevent every CSS side channel, browser bug, sanitizer bypass, or future CSS feature. It is intended to reduce exposure to known high-signal CSS exfiltration patterns while minimizing normal browsing breakage.
Technical
- Version
- 1.0.86
- Manifest
- V3
- Size
- 263KiB
- Min Chrome
- 88
- Languages
- 1
- Featured
- No
Metadata
- ID
- hkpecdfaeplhonkjjofllbihpjmhngnk
- Developer ID
- u80821a951986625683f4f310c4f6e07d
- Developer Email
- [email protected]
- Created
- May 2, 2026
- Last Updated (Store)
- May 19, 2026
- Last Scraped
- Jun 8, 2026
- Website
- —
- Support URL
- https://github.com/dougg0k/css-sentry
- Privacy Policy
- —
Data sourced from the Chrome Web Store · last verified Jun 8, 2026.