What Is TTFB (Time to First Byte)?
Time to First Byte (TTFB) measures how long a browser waits between asking your server for a page and receiving the very first byte of the response. It is the earliest signal of how fast — or slow — a page will feel, because nothing else can start until that first byte arrives.
The short version
TTFB is the delay before your server starts sending a page. A good TTFB is generally 200 ms or less, and up to 800 ms is usually acceptable. Slow TTFB almost always traces back to a slow server, an unindexed database, missing caching, or physical distance to the visitor. You can measure your own with our website speed test.
What TTFB actually measures
TTFB is the sum of three phases: the network time to reach your server (DNS lookup, connection, TLS handshake), the time your server spends generating the response, and the time for the first byte to travel back. In practice, the server-processing portion is where most problems live — the network is usually fast, but a slow application or database can add hundreds of milliseconds before a single byte is sent.
What counts as a good TTFB?
Google’s guidance treats TTFB as a diagnostic that feeds into the Core Web Vitals, particularly Largest Contentful Paint. The widely used thresholds are:
| Rating | TTFB | What it means |
|---|---|---|
| Good | ≤ 200 ms | Server responds almost instantly |
| Needs improvement | 200–800 ms | Acceptable, but worth investigating |
| Poor | > 800 ms | A clear bottleneck users will feel |
These numbers describe the response for the main document. Static assets served from cache or a CDN edge are typically much faster.
Common causes of slow TTFB
1. An overloaded or underpowered server
If your hosting is shared with many other sites, or the server is running out of CPU and memory, every request waits in line. Upgrading from crowded shared hosting to a VPS or dedicated plan often produces the single biggest improvement.
2. Slow database queries
Content-management systems like WordPress build each page by querying a database. Missing indexes, bloated tables, or dozens of plugin queries per request can add hundreds of milliseconds. Profiling and caching queries is the fix.
3. No caching
Regenerating an identical page from scratch on every visit is wasteful. A page cache stores the finished HTML so repeat requests skip the application and database entirely. This is usually the highest-impact, lowest-effort change you can make.
4. Distance between server and visitor
Data travels at a finite speed. A visitor in Australia hitting a server in Germany pays a round-trip penalty on every request. A CDN places cached copies closer to users, cutting the network portion of TTFB dramatically.
How to fix a slow TTFB
Work in order of impact: enable full-page caching first, then add a CDN, then address database and application performance, and finally consider a faster host. Also confirm you are serving modern protocols — HTTP/2 or HTTP/3 reduce connection overhead, and TLS 1.3 shortens the handshake.
Frequently asked questions
Is TTFB the same as page load time?
No. TTFB is only the wait before the first byte arrives. Full page load also includes downloading HTML, CSS, JavaScript and images, then rendering them. A fast TTFB is the foundation, but not the whole story.
Does TTFB affect SEO?
Indirectly. TTFB is not a ranking factor on its own, but it directly influences Largest Contentful Paint, which is a Core Web Vital that Google uses as a ranking signal.
What is a realistic TTFB target?
Aim for 200 ms or less for cached pages. Under 800 ms is acceptable for dynamic pages, but consistently above that indicates a bottleneck worth fixing.
Related guides
Core Web Vitals Explained for Non-Developers
LCP, INP and CLS in plain language — what Google measures, the thresholds, and how they affect rankings.
Read →Performance & Core Web VitalsHow to Improve Largest Contentful Paint (LCP)
Practical, prioritized steps to bring LCP under 2.5 seconds, from image handling to render-blocking resources.
Read →Performance & Core Web VitalsHow to Reduce Cumulative Layout Shift (CLS)
Why pages jump around while loading and the concrete fixes that keep your layout stable.
Read →Check your site against this guide
Run a free ScanOpsPro scan and see how your site handles the fundamentals.
Run a free scan