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Last updated: 2026-03-15

What is TTFB (Time to First Byte)?

Definition

TTFB (Time to First Byte) measures how quickly a server responds to a browser's request—specifically, the time from when a request is sent until the first byte of data is received. It's a crucial performance metric that reflects server speed, network latency, and backend processing efficiency.

Why It Matters

  • Directly impacts user-perceived loading speed
  • Google uses TTFB as part of Core Web Vitals assessment
  • Indicates server performance and efficiency
  • High TTFB compounds delays for all page resources
  • Critical for user experience and conversion rates

How It Works

TTFB includes three phases: request sent from browser to server (network latency), server processes the request (backend processing), and response travels back (network latency again). Server processing involves database queries, PHP execution, and content assembly. Caching, CDNs, and optimised servers reduce TTFB. It's measured in milliseconds; under 200ms is excellent, 200-500ms is acceptable, over 600ms needs improvement.

Pros & Cons

Advantages

  • Clear indicator of server performance
  • Easy to measure with browser tools
  • Directly correlates with user experience
  • Helps identify backend bottlenecks
  • Benchmarks allow host comparisons

Disadvantages

  • Varies by location and network conditions
  • Single metric doesn't tell the whole story
  • Can be misleading without context
  • Dynamic content always has higher TTFB
  • Optimising TTFB requires technical knowledge

Common Misconceptions

  • !Low TTFB means fast website (Full page load depends on many factors)
  • !TTFB is only about server speed (Network latency is a major factor)
  • !All TTFB measurements are comparable (Location and content type matter)
  • !TTFB can't be improved without changing hosts (Caching and optimisation help)

Do You Need TTFB (Time to First Byte)? Checklist

Consider ttfb (time to first byte) if any of these apply to you:

  • You've measured TTFB from multiple locations
  • Server-side caching is implemented
  • Database queries are optimised
  • A CDN is configured for static assets
  • PHP/server software is current
  • Hosting server is geographically appropriate

Recommended Hosts for TTFB (Time to First Byte)

Kinsta

Consistently sub-100ms TTFB

Read Review

SiteGround

Strong UK server performance (142ms)

Read Review

Hosting.com

Turbo servers optimised for speed

Read Review
View All Provider Reviews

Frequently Asked Questions

What is a good TTFB?
Under 200ms is excellent. 200-500ms is acceptable for most sites. 500-1000ms needs improvement. Over 1 second indicates significant problems. Compare against sites in your category for realistic benchmarks.
How do I measure TTFB?
Use browser DevTools (Network tab, look at "Waiting" time), WebPageTest.org, GTmetrix, or Google PageSpeed Insights. Test from multiple locations for accurate assessment.
Why is my TTFB high?
Common causes: slow server hardware, no caching, heavy database queries, unoptimised PHP code, distant server location, or overloaded shared hosting. Use caching plugins, optimise code, or consider better hosting.
Does TTFB affect SEO?
Yes, indirectly. Google's Core Web Vitals include server response time metrics. Slow TTFB leads to poor user experience metrics that can affect rankings. Fast sites rank better, all else being equal.
Can a CDN improve TTFB?
For cached content, yes. CDNs serve static files from edge locations closer to users, dramatically reducing TTFB for those assets. Dynamic content still requires the origin server, so TTFB for HTML may not improve.
Why does TTFB vary between tests?
Server load fluctuates, network conditions change, and caching states differ. Cached pages have lower TTFB than uncached. Test multiple times and average results for accuracy.
What is the difference between TTFB and page load time?
TTFB measures time to the first byte from the server. Page load time includes TTFB plus downloading and rendering all resources (images, CSS, JavaScript). TTFB is a component of total load time.

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