Broken Link Checker

Broken links are annoying to users and bad for SEO. A 404 on a page you care about drops search rankings, breaks conversion flows, and makes your site look neglected. Finding broken links by hand means clicking every URL, checking the response, and repeating — impossible at any real scale. This broken link checker scans entire pages or sitemaps, follows internal and external links, and flags every dead end, redirect chain, and bad response so you can fix them.

The scanner works in two modes. Page mode takes a single URL, fetches the HTML, and checks every link it finds — anchor hrefs, image src, CSS href, JS src, and CSS background images. Sitemap mode reads your sitemap.xml and checks every URL it lists, useful for site-wide audits. Results include HTTP status codes, redirect chains, response times, and content-type for each resource. Filters let you focus on 4xx errors, 5xx errors, slow responses, or mixed-content issues.

Beyond just reporting 404s, the tool catches subtler problems. A link that redirects through three hops wastes page load time and SEO authority; the tool flags chains. A mixed-content image loaded over HTTP on an HTTPS page is a browser warning waiting to happen; the scanner finds those. External links pointing to since-shut-down domains are common, and the tool identifies them with appropriate DNS or connection errors. Results export as CSV for handoff to content or dev teams. Run monthly and your site stays clean.

A link checker performs HTTP requests to every URL on a page and records the response. The scanner uses HEAD requests where possible (cheaper, no body download), falling back to GET for servers that don't support HEAD properly. Following redirects is explicit — the scanner reports the full chain up to a configurable limit (typically 5-10 hops) to catch excessive redirection.

Link extraction from HTML uses a parser (cheerio-style DOM traversal) to extract:
- anchor hrefs: <a href="...">
- image sources: <img src="...">
- CSS references: <link rel="stylesheet" href="...">
- script sources: <script src="...">
- form actions: <form action="...">
- CSS background images: url(...) in inline styles or linked CSS
- meta refresh: <meta http-equiv="refresh" content="0; url=...">

For sitemap mode, the tool parses sitemap.xml (and sitemap indexes), extracts <loc> elements, and queues each URL. Large sitemaps are processed in batches with concurrency limits to avoid hammering target servers.

Response codes and their meanings:
- 2xx: success — ok
- 3xx: redirect — followed, warn on long chains (5+)
- 4xx: client error — report prominently (404, 403, 410)
- 5xx: server error — may be transient, retry once
- DNS/connection errors: domain gone or server unreachable

Mixed content detection compares the page scheme (https) with each linked resource's scheme (http). Any HTTPS page loading HTTP resources triggers mixed-content warnings in modern browsers. CSV export includes URL, status, redirect chain, response time, content type, and source element type for each finding.

Desktop tools like Screaming Frog are powerful but cost money and have learning curves. Browser plugins work for small pages but struggle with sitemap-scale audits. Command-line tools like wget with link checking need setup. This browser-based tool handles page and sitemap scanning, covers all link types, detects mixed content and redirect chains, exports CSV, and has no installation or account required. Ideal for occasional audits and quick validation before deploys.