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Rescue 404
Rescue

Free tool

Why is this URL failing?

Public HTTP status, TLS expiry, DNS A/CNAME, redirect chain, and TTFB — paste a URL, no login. Plain-language diagnosis, not just up or down.

Primary use
Emergency triage when a site will not load and you need to know whether DNS, SSL, redirects, or the origin failed.
Estimated time
About 1 minute
Input type
Requires a domain/URL
Use the tool All free tools

One GET, plus up to five redirect hops. No crawl. No malware scan. No login.

What this checker answers

Paste a public URL. The checker explains why that address is failing — or confirms it responded — using the same signals a technician glances at first: DNS, TLS expiry, the redirect chain, HTTP status, and time to first byte.

  • DNS A, AAAA, and CNAME for the hostname
  • TLS certificate dates on HTTPS hops
  • Redirect chain up to five hops, with per-hop status
  • Final HTTP status and time to first byte (TTFB)

How this is different from other free checkers

Most free “is it down?” pages only say up or down. Redirect tools dump hop lists. SSL graders take minutes and score cryptography. This page leads with a plain-language reason, then the evidence, with no login and no ads.

  • One paste covers DNS + TLS + redirects + status + TTFB instead of five separate websites
  • The first line is a diagnosis (“failing because…”), not a raw packet dump
  • Shareable result URL so you can send the same check to a host or developer
  • Findings link to Rescue 404 repair guides when the failure has a named error
  • Hard limit: one GET on the submitted URL (plus bounded redirect hops). No crawl. No malware payload scan

When to use it

Use this when a site “just went down,” a client forwards a URL that errors, or you need to separate DNS from hosting from SSL before anyone starts guessing in wp-admin.

Methodology

  • Validates the URL (http/https only) and blocks localhost, private, link-local, and metadata addresses.
  • Resolves DNS, then pins the request to a public IP so a later DNS change cannot steer the GET at an internal host.
  • Issues one GET per redirect hop (maximum five), records status, Location, TTFB, and TLS dates. It does not follow page links.
  • Interprets the evidence into a headline. HTTP 200 with a 4-second TTFB is not treated as “fine.”

Limitations

  • Not an uptime monitor, crawler, malware scanner, or SSL Labs-style grade.
  • JavaScript-rendered errors and logged-in failures will not appear.
  • TTFB is measured from this server’s network path, not from your office or a CDN edge in another region.
  • Certificate hostname matching uses the names on the presented leaf certificate; it is not a full chain or CAA audit.

Privacy

Submit only public URLs. The service retrieves headers and a truncated homepage body to measure TTFB and (for the SSL checker) mixed content, then discards the HTML. It does not return page HTML to your browser.

FAQ

Plain answers about what this tool does and does not claim.

Does a green result mean every visitor can load the site? +
No. This is one GET from Rescue 404’s server. Regional DNS, a CDN cache, a logged-in path, or a mobile app can still fail. Treat a success as “the public homepage URL responded here,” not a global uptime SLA.
Why only one GET? +
Open URL checkers get abused as crawlers and scanners. This tool follows the submitted URL’s redirect chain (max five hops), then stops. It does not fetch images, scripts, sitemaps, or other pages, and it does not scan the response for malware.
Is this the same as Down for Everyone or SSL Labs? +
No. Those answer one narrow question (up/down, or a deep cryptographic grade). This checker is the emergency triage view: why this URL is failing, in language you can send to a host. It is not a penetration test and not an SSL Labs replacement.
Do I need an account? +
No. Paste the URL. Results are not gated behind email. If you want a technician to fix what the check found, Request Rescue is optional.
What if the inspect service is rate-limited? +
Each IP is limited to keep this from becoming an open proxy. Wait a few minutes and try again, or send the URL through Request Rescue if the site is in a live outage.
Are checked URLs stored? +
The check is processed to return this result. Do not submit URLs that require login, private file paths, or credentials in the URL. Local, private, and metadata addresses are blocked.

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