What is TTFB (Time to First Byte)?

TTFB is the time between a browser sending an HTTP request and receiving the first byte of the server response. It includes DNS lookup, TCP connection, TLS handshake and server processing time. A low TTFB indicates a fast, well-configured server.

Google's Core Web Vitals guidelines classify TTFB as: Good if under 200ms, Needs Improvement between 200-500ms, and Poor if over 500ms. Most high-performance websites aim for TTFB under 100ms.

How does TTFB affect SEO?

TTFB directly impacts Largest Contentful Paint (LCP), one of Google's Core Web Vitals ranking signals. A slow TTFB delays all subsequent page loading, resulting in worse LCP scores and potentially lower search rankings.

Common causes: slow database queries, server geographically far from users, heavy application logic, shared hosting overload, or missing server-side caching (Redis, Varnish, OPcache). Using a CDN is the fastest way to reduce TTFB globally.

How can I reduce my TTFB?

Key fixes: (1) Use a CDN like Cloudflare to cache responses near users. (2) Enable server-side caching (Redis, Memcached, Varnish). (3) Optimize database queries and enable OPcache. (4) Upgrade to a VPS or dedicated server. (5) Choose a hosting region close to your audience.

Is this TTFB checker free?

Yes, the TTFB checker tool on uptimelock.com is completely free to use with no account required.

Web tools

TTFB checker

Verify the time to first byte of any website.

Server Response Core Web Vitals < 200ms Fast Lighthouse CDN Impact Hosting Speed

What is TTFB?

TTFB (Time to First Byte) measures the time between an HTTP request and receiving the first byte of the server's response. It is a key indicator of server responsiveness and a factor in Google's Core Web Vitals.

TTFB Performance Thresholds

Fast (< 200 ms)

Excellent. Very responsive server, good for SEO and UX.

Moderate (200 - 500 ms)

Acceptable, but server-side optimizations are recommended.

Slow (> 500 ms)

TTFB too slow. Negative impact on Google ranking and user experience.

Causes of High TTFB

Slow or unoptimized database queries.
Server geographically far from the user (use a CDN).
Complex application logic or unoptimized PHP/Node code.
Overloaded shared hosting or insufficient server resources.
Missing server-side cache (Redis, Memcached, OPcache not configured).

How to use this tool?

1Enter the full URL of the site or page to test (with https://)
2Click submit to measure the server response time
3Review the measured TTFB and compare it against performance thresholds

How to improve your TTFB?

Use a CDN (Cloudflare, Fastly) to reduce network distance.
Optimize SQL queries and enable database caching.
Upgrade to VPS or dedicated hosting for more resources.
Enable OPcache (PHP) or response caching (Redis/Varnish).
Choose a server location close to your target users.

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