--- title: "Detecting browser extensions for bot detection, lessons from LinkedIn and Castle" url: https://daily.dev/posts/detecting-browser-extensions-for-bot-detection-lessons-from-linkedin-and-castle-nu1uxbkhl source_url: https://securityboulevard.com/2026/01/detecting-browser-extensions-for-bot-detection-lessons-from-linkedin-and-castle/ type: article source: "Security Boulevard" published: 2026-01-14T10:50:48.357Z updated: 2026-01-14T10:51:14.109Z tags: ["javascript", "google-chrome", "web-security"] reading_time: 14 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Detecting browser extensions for bot detection, lessons from LinkedIn and Castle **[Security Boulevard](https://daily.dev/sources/securityboulevard)** · 14 min read · 0 upvotes · 0 comments ## Summary Browser extensions leave detectable traces that can serve as signals for bot detection systems. LinkedIn probes chrome-extension:// URLs to detect installed extensions by attempting to fetch web-accessible resources, but this creates console noise and performance overhead. Castle uses a stealthier approach by observing DOM mutations, custom elements, and JavaScript globals that extensions inject into pages. While neither method can enumerate all extensions, both provide valuable contextual signals when combined with other fingerprinting techniques. The side-effect approach trades detection breadth for reduced observability and better performance. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [LinkedIn Is Scanning Your Browser Extensions. This Is How They Use the Data. — 404](https://daily.dev/posts/linkedin-is-scanning-your-browser-extensions-this-is-how-they-use-the-data-404-dtdjj0lhi) · Hacker News · 1 upvotes · 0 comments - [Spying Chrome Extensions: 287 Extensions spying on 37M users](https://daily.dev/posts/spying-chrome-extensions-287-extensions-spying-on-37m-users-zc89tp8r9) · Hacker News · 0 upvotes · 0 comments - [mdp/linkedin-extension-fingerprinting](https://daily.dev/posts/mdp-linkedin-extension-fingerprinting-5ix8yfsbw) · Hacker News · 0 upvotes · 0 comments --- Tags: [#javascript](https://daily.dev/tags/javascript), [#google-chrome](https://daily.dev/tags/google-chrome), [#web-security](https://daily.dev/tags/web-security) [View this post on daily.dev](https://daily.dev/posts/detecting-browser-extensions-for-bot-detection-lessons-from-linkedin-and-castle-nu1uxbkhl)