My site is broken
Start with the website setup report. If your public site and origin disagree, compare both endpoints using your server IP. Origin checks require domain verification.
53 free tools for people who run websites
Check, fix and configure your website
Investigate broken pages, slow loads and hosting changes. Start with a website setup check, or choose a deeper investigation with evidence you can retest.
Start with the problem you have
Choose a focused check, review its evidence, then repeat the same measurement after a change.
My page loads slowly
Measure a public page with one screen size and inspect its requests and rendering. If you already have a HAR capture, analyze it locally instead.
I am moving to a new host
Compare the current site with the proposed server before changing DNS. Supply the new public server IP, verify the domain and state the responses you expect.
I need to check a release
Compare the released and baseline pages at the same screen size, then test a short journey with explicit expected content. Click and fill steps need domain verification.
Is it down or is it me?
Check the site from our server, then look at what your own connection can reach.
Want the full explanation?
Our guides walk through common problems step by step and link to the tool that confirms each fix.
Read the guidesGood places to start
Focused checks for setup, hosting moves, performance and releases.
See the A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records for any domain.
Check a certificate's expiry, covered names, chain and supported TLS versions.
Follow a URL through every redirect and spot loops, HTTP downgrades and long chains.
Compare the current site with a proposed server before changing DNS.
Repeat a browser measurement and inspect timing, requests and rendering evidence.
Compare two rendered pages and inspect screenshots and their pixel differences.
Browse by category
- DNS and DomainsLook up records, follow a DNS change and inspect domain registration and expiry details. DNS Lookup · DNS Propagation Checker · WHOIS Lookup 9
- EmailCheck and build MX, SPF, DKIM and DMARC records for mail routing and sender authentication. MX Lookup · SPF Checker · DKIM Checker 7
- SSL and SecurityInspect certificates and the security headers your server sends to browsers. SSL Checker · Security Headers Checker · SSL Issuance & Renewal Debugger 5
- HTTP and RedirectsFollow redirects, read response headers and check status codes for one URL or many. Redirect Checker · HTTP Status Checker · HTTP Header Viewer 12
- Technical SEOTest crawler rules and review the tags search engines and social sites read from a page. Robots.txt Tester · Meta Tag Checker · XML Sitemap Validator 7
- Config GeneratorsBuild cron schedules, robots.txt files and redirect rules you can paste straight into your server. Robots.txt Generator · Cron Expression Builder · .htaccess Redirect Generator 6
- Network and IPSee your public IP, look up any IP address, test open ports and check whether a site is down. What Is My IP · IP Lookup · Is It Down? 7
Troubleshooting guides
Step-by-step fixes for common problems, each linked to the tool that confirms it worked.
- HostingTest a new hosting server before changing DNS6 min
- HTTPCloudflare and your origin return different responses5 min
- PerformanceFind the element and requests behind a slow page6 min
- SSLHTTPS warning after a site move: DNS, certificates and redirects5 min
- HTTPInvestigate a 403, 404, 502 or 504 website response5 min
- Technical SEOA page is crawlable but not indexed: what to check5 min
- EmailSet up email DNS while preserving working mail5 min
- NetworkWhy a TCP port checker reports closed or timed out5 min
- RedirectsFix ERR_TOO_MANY_REDIRECTS: find and break a redirect loop7 min
- EmailEmails going to spam? Check SPF, DKIM and DMARC in this order9 min
- DNSDNS change not showing up? How propagation really works6 min
- Server configCron job not running? Seven things to check6 min
How NosHost tools work
Results explain the fix
Warnings say what is wrong, why it matters and what to change, with config you can copy.
No account needed
Run any tool without signing up. Generators and the header analyzer work entirely in your browser.
Choose a useful next check
Related tools and guides help you investigate the evidence. Review the target and settings before each run.