Slow time to first byte (TTFB)

Also searched as: time to first byte slow

Updated 11 October 2026

Short answer

Time to first byte is how long a browser waits between asking for a page and getting the first piece of it back. It includes the connection setup and the time your server spends building the page. Google's guidance is 0.8 seconds or less. A slow TTFB is almost always the server's work: no caching, slow database queries, or an underpowered or distant server. Speeding up images and scripts won't fix it.

What's the problem

Speed tests flag a slow "time to first byte" or "server response time", and pages show a blank screen for a while before anything appears.

Why it happens

  • No page caching: every visit rebuilds the page from the database.
  • Slow or numerous database queries per page.
  • Slow plugins or code running on every request.
  • An overloaded or underpowered server.
  • The server is far from visitors and there's no CDN.
  • Redirect chains adding extra round trips before the real page.

How to fix it

  1. Measure TTFB for a few pages: in Developer Tools → Network, click the page request and look at "Waiting for server response".
  2. Add page caching for pages that are the same for every visitor, at the server or a CDN.
  3. Find slow queries with your database's slow-query log, and add indexes or reduce them.
  4. Remove or replace slow plugins.
  5. Cut redirect chains so links go straight to the final address.
  6. Upgrade hosting or move closer to your visitors if the basics are already done.

What Preventionlabs checks

One click runs the full report on your domain. For this problem it shows whether your site loads, how fast, and where its redirects go; how long each of up to 50 pages takes to download; page weight, oversized images and caching. With Cloudflare connected, it also shows your visitor trend over 4 weeks. It measures from our checker, not from your visitors' phones, so test on a phone too.

Run your free report

Your first report is free, no card needed. Then A$50 a month, up to 10 domains. Read-only: it never changes anything.

Sources

  1. MDN Web Docs: Time to First Byte (TTFB)referenceTime to First Byte ( TTFB ) refers to the time between the browser requesting a page and when it receives the first byte of information from the server.
  2. web.dev (Google): Time to First Byte (TTFB)referenceAs a rough guide, most sites should strive to have a TTFB of 0.8 seconds or less.

Related

Why is my website slow? Find out which part is slow: the server producing the page, or the browser loading heavy files. Measure first, then fix the slowest part. Database timeout A query or connection took longer than allowed: usually a slow query on a big table, a missing index, locked rows, or an overloaded database. Server overloaded More work than the server can handle: a traffic spike, bots, a runaway process, or a slow query. Find what's using the CPU before upgrading. Website timeout Something waited too long and gave up: the browser, a proxy such as Cloudflare, or your server. The error tells you which one, and so where the slowness is.
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