Website & HTTP tools
Status codes, headers, redirects, HTTP/2 & HTTP/3, compression, speed, robots, sitemaps.
Confirm your server compresses responses with gzip or Brotli.
HTTP headers viewerSee all response headers and which security headers are present.
HTTP status checkerCheck any URL's HTTP status code, response time, redirects, and headers.
HTTP/2 & HTTP/3 testSee which modern HTTP protocols your server negotiates.
Meta & Open Graph previewSee your page's title, description, and social cards as platforms render them.
Redirect tracerFollow a URL's full redirect chain, hop by hop.
Robots.txt testerFetch and validate robots.txt and test whether a URL is allowed.
Sitemap validatorCheck your XML sitemap is well formed, reachable, and within limits.
Website speed / TTFBMeasure time to first byte and total response time.
A page can be "up" and still be quietly broken — slow, returning the wrong status, missing compression, or blocked from search by a stray robots rule. These free website and HTTP tools let you inspect status codes and headers, trace redirects, confirm modern protocol and compression support, measure speed, and validate your robots.txt and sitemap. Run a quick audit any time, then let SJ Monitor's HTTP and response-time monitoring watch the page continuously and alert you when it goes down or slows past your threshold.
Frequently asked questions
My site loads but feels slow — where do I start?
Check time to first byte with the speed tool, confirm compression and HTTP/2 or HTTP/3 are enabled, and review redirects that add round trips. Each has a tool here.
Can SJ Monitor alert me on slowdowns, not just outages?
Yes. Response-time monitoring warns you when your endpoints get slow, before they fail outright.
My page returns 200 but something looks broken — what should I check?
A 200 only means the server responded; the content can still be wrong. Use the redirect tracer for unexpected hops, the headers viewer for caching or security misconfig, and the robots tester to confirm you haven't accidentally blocked crawlers.
How can a stray robots.txt rule hurt me?
A single Disallow: / blocks compliant crawlers from your whole site and can quietly deindex you from search. Always test robots.txt after a deploy, since CMS and framework changes can overwrite it.
Do HTTP/2 and HTTP/3 actually make my site faster?
Often yes — HTTP/2 multiplexes requests over one connection, and HTTP/3 over QUIC recovers faster on lossy or mobile networks. Most CDNs enable both with a toggle; the HTTP version test confirms what your server negotiates.
Other tool categories
Want any of this watched around the clock? Turn on SJ Monitor's HTTP & response-time monitoring — create a free account and we'll alert you the moment something changes.