Extenshi provides an independent public catalog of browser extensions and related information (“Extension Data”). Extension Data is collected from publicly available sources, including third-party extension stores and public web pages.
Data sources
Extension Data may be collected from:
- Live store pages: Current publicly accessible pages from Chrome Web Store, Firefox Add-ons, and Microsoft Edge Add-ons.
- Web archives: Historical snapshots from public web archives such as CommonCrawl (WARC files containing past versions of extension store pages) and the Internet Archive's Wayback Machine (archived API responses containing extension metadata, permissions, and version history).
- Public APIs and sitemaps: Publicly available data feeds provided by extension stores.
- Community discussion platforms: Public discussions mentioning extensions on third-party platforms such as Hacker News (retrieved via the Algolia API). This data may include story titles, URLs, authors, scores, and comment counts.
- Target website metadata: Public metadata about the websites an extension is configured to interact with, derived from the host and match patterns declared in the extension's manifest. Where such a website is publicly accessible, our automated crawler may retrieve the page's public title, description, and favicon to label and group extensions by the sites they affect.
- Developer website reachability: Periodic automated requests to the websites a listing itself declares (for example its homepage or support URL) to determine whether the address is still live, has been parked, or no longer resolves. What we retain from these requests is the resulting liveness verdict, which is one of the inputs to the maintenance assessment described in our Security & Risk Disclaimer.
Data processing
Extension Data is processed through automated pipelines that:
- Extract metadata from HTML pages using automated parsing systems.
- Normalize and validate data across multiple sources and time periods.
- Store historical versions to provide timeline and version history features.
Limitations
- We are not affiliated with, endorsed by, or sponsored by any browser vendor or third-party store unless expressly stated.
- Extension Data may be incomplete, inaccurate, or outdated due to the nature of automated collection and parsing.
- Historical data from web archives may not reflect the current state of an extension or may contain parsing artifacts.
- Any ratings, categorizations, or insights provided by Extenshi are for informational purposes only.
Community discussion data
Extension detail pages may display public discussions from third-party platforms (such as Hacker News). This data is sourced from public APIs and reflects third-party user opinions, not Extenshi editorial positions. Discussion data may be incomplete or contain inaccuracies. Registered users may submit feedback on the accuracy of linked discussions; see our Privacy Policy for details on how feedback data is processed.
User reviews
Extension detail pages may display user reviews originally posted on third-party extension stores. These reviews are user-generated content that belongs to the individual reviewers and the store on which they were posted; they reflect third-party opinions, not Extenshi editorial positions, and may be incomplete, outdated, or inaccurate.
- Excerpts, not full text: Firefox Add-ons and Microsoft Edge Add-ons reviews are shown only as short excerpts, with a link to the full review on the originating store.
- Chrome Web Store: we do not reproduce Chrome Web Store review text. For Chrome listings we show only the aggregate rating and review count, with a link to the reviews on the Chrome Web Store.
- No reviewer identity: we do not publish reviewer names, avatars, or other reviewer-identifying details.
- Store attribution: each review or rating is attributed to its originating store, which remains the authoritative source.
- Removal: a review that is removed on the originating store is removed from our catalog as well. To request removal of a specific review or your reviewer information, use our Content removal & takedown policy.
Target website metadata
Many extensions declare, through the host and match patterns in their manifest, the websites they are designed to interact with. To let you browse and group extensions by the sites they affect, Extenshi may make automated requests to those publicly accessible websites — identifying itself as “ExtenshiBot” — and retrieve each site's public page title, description, and favicon. Only publicly available metadata is collected; we do not submit forms, sign in, or access non-public areas of these sites, and results are cached to limit repeat requests. These websites are operated by third parties, are not part of Extenshi, and are not under our control; their metadata is displayed for informational and navigational purposes only and may be incomplete, outdated, or inaccurate.
Third-party links and websites
Extension Data mirrored from third-party stores frequently includes links to external websites operated by extension authors or other third parties (for example an extension’s homepage or support URL, an author’s declared privacy policy or contact site, and links inside store descriptions). These sites are not part of Extenshi and are not under our control. We do not control, monitor, endorse, sponsor, or assume responsibility for the content, legality, or practices of any linked third-party site, and the presence of a link is a reproduction of public store data, not a recommendation. Following any external link is at your own risk. We may disable or annotate a link at our discretion — for example, where automated signals indicate a destination distributes gambling, malware, or other harmful or unlawful content, we may display it as plain, non-clickable text with a warning. To report a harmful link, see our Content removal & takedown policy. See also the “Third-party links and websites” section of our Terms of Service.
Extension lifecycle status
Extensions in our catalog may have various processing statuses (e.g., active, failed to process, quarantined). These statuses reflect our internal pipeline state and do not indicate the actual availability or status of the extension in its original store.
If you believe Extension Data about an extension is incorrect, please contact [email protected] with supporting details.