Recursive Find

Ctrl+F, but recursive. Searches the current page and every page it links to, down to a customizable depth. Text-only parsing, matching powered by Knuth–Morris–Pratt (KMP), crawling done in parallel across a pool of real worker threads. Lives in the Chrome side panel, so it stays open while you work (Chrome 114+).

Install (unpacked)

1. Open chrome://extensions
2. Toggle Developer mode (top right)
3. Click Load unpacked and select this folder
4. Pin the extension and click its icon on any http(s) page

Use

• Type a search term, set Depth, and hit Find.
• Depth 0 = current page only. Depth 1 (default) = current page + every page it directly links to. Depth 2 = also their links, etc. (capped at 5).
• Match mode:
  • Text — plain substring match (KMP).
  • Whole word — substring match with word-boundary filtering (cat won't match category).
  • Regex — JavaScript RegExp pattern; invalid patterns are reported before the crawl starts.
• Match case toggles case sensitivity.
• Same site only restricts the crawl to the starting page's origin.
• Stop at first hit ends the whole crawl the moment any page matches.
• Each result shows a text preview; pages with no match are tucked into a collapsed "N pages with no match" dropdown at the bottom.
• Results stream in live, sorted by hit count. Click a result to open it in a new tab, scrolled to and highlighting the match (via a #:~:text= fragment).

Architecture

• popup.* — the side panel. Reads the active tab's text + links, owns the Web Worker pool, and runs the BFS crawl. A visited set (URLs normalized by stripping the hash + trailing slash) guarantees each page is fetched once.
• worker.js — one dedicated worker per thread. Given a URL it fetches, strips HTML to text, runs KMP, and extracts links — all off the main thread. The pool is sized to hardwareConcurrency - 1 (2–8), so pages are fetched and searched genuinely in parallel.
• kmp.js — O(n + m) exact substring search.
• background.js — only configures the side panel to open on the toolbar click.

Regenerating icons

Icons are generated procedurally — node gen_icons.js rewrites icons/*.png.

How it works

• popup.* — UI; opens a streaming Port to the service worker.
• background.js — reads the active tab's text + links, then BFS-crawls the link graph level by level (6 concurrent fetches, 300-page cap), strips each fetched page to text, and runs KMP over it.
• kmp.js — O(n + m) exact substring search with an LPS failure table.

Limits / notes

• Cross-origin pages are fetched from the service worker using host_permissions: <all_urls>.
• Text extraction is a regex strip (no DOM in MV3 workers), so JS-rendered content on linked pages won't be seen — only server-delivered HTML text.
• Non-HTML links (PDFs, images) are skipped.