Free Website, DNS, SSL & Uptime Tools
Check SSL, DNS, email, HTTP and domain problems with live results. No signup required.
- SSL CheckerPopularCheck a site's SSL certificate, expiry date and whether the intermediate certificate is installed.SSL & TLS →
- TLS Version CheckerSee which TLS versions a server accepts, from TLS 1.0 to TLS 1.3, and the cipher it picks for each.SSL & TLS →
- Bulk SSL CheckerCheck SSL certificates for up to 50 hostnames at once: expiry, days left, chain and issuer, with CSV export.SSL & TLS →
- WHOIS LookupLook up a domain's registrar, registration and expiry dates, status flags, nameservers and DNSSEC.Domain →
- Domain Expiry CheckerSee exactly when a domain expires and how many days are left before renewal.Domain →
- Website Down CheckerPopularCheck if a website is down for everyone or just you, with status code, response time and final URL.Website & Uptime →
- Redirect CheckerTrace every redirect hop of a URL with status code, Location and time, and spot loops and long chains.HTTP & Status Codes →
- Website Response Time TestMeasure how long a website takes to respond, split into DNS, connect, TLS, server wait and download.Website & Uptime →
- Keyword CheckerCheck whether a word or phrase appears in a web page's HTML, with the number of matches and status code.Website & Uptime →
- Security Headers CheckerGrade a site's HTTP security headers (HSTS, CSP, X-Frame-Options and more) from A+ to F.HTTP & Status Codes →
- Website Compression CheckerNewCheck whether a website compresses its pages with Brotli, gzip or zstd, and how many bytes each one saves.HTTP & Status Codes →
- Port CheckerCheck if a TCP port is open, closed or filtered on a host, with the connect time.Website & Uptime →
- Cron Job Heartbeat TesterNewGet a temporary heartbeat URL and watch pings from your cron job or script arrive live.Website & Uptime →
- HTTP Status Code CheckerPopularCheck the HTTP status code any URL returns, with response time and every redirect on the way.HTTP & Status Codes →
- 502 Bad GatewayCheck if a URL returns 502 Bad Gateway right now, and find the cause: upstream down, PHP-FPM, Cloudflare or a load balancer.HTTP & Status Codes →
- 503 Service UnavailableCheck if a URL returns 503 Service Unavailable, and fix maintenance mode, overload, rate limits and empty backend pools.HTTP & Status Codes →
- 504 Gateway TimeoutCheck if a URL returns 504 Gateway Timeout, and find the slow upstream: proxy timeouts, slow queries, API Gateway and CDN limits.HTTP & Status Codes →
- 403 ForbiddenCheck if a URL returns 403 Forbidden, and fix file permissions, missing index files, WAF and bot rules, IP blocks and S3 access.HTTP & Status Codes →
- 429 Too Many RequestsCheck if a URL returns 429 Too Many Requests, read Retry-After, and fix rate limits on your server or in your API client.HTTP & Status Codes →
- CNAME CheckerPopularCheck where a hostname's CNAME points, its TTL, the full chain and the final IP address.DNS →
- DNS LookupPopularLook up A, AAAA, CNAME, MX, TXT, NS, CAA and SOA records for any domain, with TTLs, from public resolvers.DNS →
- MX LookupFind the mail servers for a domain, in priority order, with TTLs and each server's IP addresses.DNS →
- TXT Record LookupSee every TXT record on a name, with SPF, DMARC, DKIM and domain verification tokens recognised.DNS →
- Domain to IP LookupFind the IP addresses behind a domain: A and AAAA records with TTLs, the CNAME chain and reverse DNS.DNS →
- Reverse DNS LookupFind the PTR hostname for an IP address and check that it resolves back to the same IP.DNS →
- Email Health CheckPopularScore a domain's email setup: MX, SPF, DMARC, DKIM and MTA-STS, with the issues to fix first.Email →
- SPF CheckerValidate a domain's SPF record, count its DNS lookups against the limit of 10 and check the all qualifier.Email →
- DMARC CheckerLook up a domain's DMARC record and see its policy, reporting addresses and alignment settings explained.Email →
- Uptime SLA CalculatorTurn an uptime percentage into allowed downtime per day, week, month, quarter and year, or downtime into a percentage.Calculators →
- Downtime Cost CalculatorEstimate what an outage costs in lost revenue and staff time, in USD, MYR, SGD, EUR, GBP and more.Calculators →
Free tools tell you what is wrong now. TinyPing tells you when it goes wrong later: every 5 minutes, by email, Slack or Google Chat.