What is Time to First Byte?
Time to First Byte (TTFB) is the duration between a user's browser initiating an HTTP request and the server sending back the first byte of data in response. It's measured from the user's perspective and includes DNS lookup time, connection establishment, and server processing time.
TTFB is typically measured in milliseconds and represents how quickly your server responds to requests. A faster TTFB means your website can start loading content sooner, improving the overall user experience.
Why TTFB Matters for Marketing
For UK marketing agencies, TTFB directly impacts campaign performance and conversion rates. Google includes Core Web Vitals in its ranking algorithm, and whilst TTFB itself isn't a Core Web Vital, it's a foundational metric that affects Largest Contentful Paint (LCP) – which is. Slow TTFB can lead to higher bounce rates, reduced ad effectiveness, and lower ROI on paid media campaigns.
When running digital campaigns – whether PPC, display, or affiliate marketing – pages with poor TTFB create friction in the user journey. For e-commerce clients, even 100ms delays can impact conversion rates, directly affecting campaign profitability.
Typical TTFB Benchmarks
- Excellent: Under 100ms
- Good: 100-300ms
- Acceptable: 300-1000ms
- Poor: Over 1000ms
Google recommends keeping TTFB under 600ms for optimal performance.
What Affects TTFB?
Server-side factors include server capacity, processing power, and code efficiency. A poorly optimised backend or underpowered hosting will increase TTFB.
Network factors include geographic distance between user and server, ISP routing, and network congestion. UK-based users accessing servers hosted abroad may experience higher TTFB.
Database queries and API calls can slow response times significantly if not optimised.
How to Improve TTFB
- Upgrade hosting or use a Content Delivery Network (CDN) with UK server locations
- Optimise server-side code and database queries
- Implement caching strategies (page caching, object caching)
- Use a reverse proxy or load balancer
- Minimise redirects
- Choose quality hosting providers with robust infrastructure
Measuring TTFB
You can measure TTFB using Google PageSpeed Insights, Google Analytics 4, WebPageTest, or your server's native monitoring tools. Regular monitoring helps identify degradation before it impacts campaign performance.
For media buyers, understanding TTFB helps explain landing page performance variations and informs technical optimisation recommendations for clients.