What is TTFB? Time to First Byte in plain English
TTFB is the wait before your browser receives the first byte of the HTTPS response. It is an early “is the origin or edge healthy?” signal—not a full Lighthouse or Core Web Vitals score.
What is Time to First Byte?
Time to First Byte (TTFB) measures elapsed time from starting the request until the first response byte arrives. It includes DNS (if not cached), TCP/TLS setup, and how long the server or CDN takes to begin the body. A high TTFB usually points at backend work, cold caches, distant origins, or a stuck TLS handshake—not at image size or JavaScript weight further down the page.
What CrowWake checks
CrowWake’s performance pulse times a single HTTPS GET of your apex and records elapsed milliseconds plus HTTP status—the same TTFB-style signal as the free performance checker. Over ~1.5s → warn. Over ~3s or HTTP 5xx → louder. We sample a limited body size for a rooster, not a full lab crawl. Site-up and SSL sit beside it so “slow,” “down,” and “cert expired” stay separate. For the repeat “watch first-byte hourly” job, see the dedicated website performance monitoring guide.
TTFB vs full page speed
A good TTFB does not guarantee a fast Largest Contentful Paint. Caching can hide a slow origin on one hit and expose it on the next. Operators searching “website slow TTFB” or “how to fix high TTFB” usually need origin/CDN triage first; CrowWake’s job is to crow when the first-byte pulse stays ugly, not to replace a synthetic monitoring suite.
What “good enough” looks like
Consistent sub-second or low-second first-byte times from the probe region. Occasional spikes happen—CrowWake cares more about sustained sluggishness than a single lab run. CDN cache hits and a healthy origin usually keep TTFB calm; multi-region probes later will compare notes.
Quick triage when TTFB goes yellow
1) Re-run the free performance checker and note ms + HTTP status. 2) Confirm the apex still resolves and TLS handshakes (DNS A + SSL checkers)—a hanging handshake looks like slow TTFB. 3) Check CDN cache hit rate and origin CPU/DB. 4) Look for a recent deploy, cache purge, or regional outage. 5) Add the domain so CrowWake crows on the next sustained spike instead of waiting for a client email.
If CrowWake crows
Check origin CPU, database, CDN cache misses, and recent deploys. Confirm DNS apex and TLS still look healthy. If HTTPS never answers, fix site-up first; if the cert is expired, renew before chasing ms. After a fix, re-run the free performance pulse and keep watching. Deeper Performance+ sampling is planned for paid slots—this check is the TTFB rooster. For the hourly website performance monitoring framing, see the dedicated guide.
Watch this on CrowWake
Add the domain, leave the boxes checked, and the flock will crow when this drifts.
Or try the free TTFB / performance checker with no login.
Deep dive: Website performance monitoring — watch the TTFB-style first-byte pulse hourly, with the same free performance checker.
Related: performance pulse overview, uptime monitoring, and the free SSL expiry checker (a hanging handshake looks like slow TTFB).