What is TTFB (Time to First Byte)?
The time from when a browser requests a page to when it receives the first byte of data from the server.
Why It Matters
TTFB indicates server responsiveness and affects all subsequent loading metrics.
Real-World Example
A TTFB of 800ms means the server takes nearly a second before it even starts sending the page.
“Understanding terms like TTFB (Time to First Byte) matters because it helps you have better conversations with developers and make smarter decisions about your software. You do not need to be technical. You just need to know enough to ask the right questions.”
Related Terms
LCP (Largest Contentful Paint)
A metric measuring how long it takes for the largest visible content element to finish loading.
Latency
The time delay between a request and its response
Server
A computer that runs continuously to handle requests, store data, and serve your application to users
CDN
A network of servers around the world that stores copies of your content closer to users
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Related Terms
Server
A computer that runs continuously to handle requests, store data, and serve your application to users
CDN
A network of servers around the world that stores copies of your content closer to users
Latency
The time delay between a request and its response
LCP (Largest Contentful Paint)
A metric measuring how long it takes for the largest visible content element to finish loading.
Cache
A temporary storage that keeps copies of frequently accessed data for faster retrieval
Throttling
Slowing down requests instead of blocking them entirely when limits are approached