Website speed test
Quick TTFB and payload hints from our network: first-byte timing, a capped body sample, and headers that describe size and compression.
What this speed sample measures
“How fast is this URL?” usually means time to first byte (TTFB), how large the response is, and whether compression or caching headers look sane. Synthetic tests never tell the whole UX story, but they are fast signals for regressions after deploys or CDN changes.
We stream only the start of the response body to estimate TTFB without pulling multi-megabyte assets through our tool. Content-Length and encoding headers—when present—hint at full payload size and compression.
Combine with the latency and header tools when you are building a picture for an incident or a performance review.
How this tool works
Short technical summary of what runs on our servers when you click the button.
We follow redirects with the same validation as other URL tools, then measure until the first chunk of body data arrives and a small sample is read.
TTFB is when the first bytes arrive; total time includes reading a capped portion of the body so large pages do not exhaust bandwidth.
Private hosts and SSRF-prone targets are blocked.
More BuildSpace tools
All utilities run from our infrastructure with the same safety limits. No account required.
- Site statusSee if a URL responds from our servers—outage vs. local issue.
- DNS lookupA, AAAA, MX, CNAME, TXT, and NS records for a domain.
- HTTP header checkerStatus code, full response headers, and common security headers.
- SSL certificate checkerCertificate subject, issuer, validity, fingerprint, and SANs.
- Ping & response timeThree-run DNS, TCP, and HTTP timing breakdown (no ICMP).
- WHOIS (RDAP)Registrar and registration data via RDAP where available.
- Open port checkerTCP connect test to a host and port from our network.