Servers, hosting, caching and CDNs
Where the first byte comes from: hosting, caching layers, CDNs and protocols, and how they decide how fast a page starts.
Before a browser can show anything it needs the first byte of the page from a server. How long that takes depends on where the server is, how much work it does for each visit, and whether a copy can be served from a cache instead. These guides cover hosting, the different kinds of caching, CDNs and the protocols between the browser and the server.
Start with the wait itself. Time to first byte shows what that first wait is made of, and server response time shows how to shorten the part your server controls.
Then the biggest levers. Choosing hosting for speed sets the floor. Caching explained names the layers, and the Cache-Control cheat sheet and HTTP caching headers give the settings. What a CDN is covers distance.
Then the details. Text compression, HTTP/2 and HTTP/3, DNS, TLS and connections and the back/forward cache finish the picture.
Guides in this topic 11 guides
- Caching explained: browser, CDN, page and object cache
Caching saves a finished copy so the work is not done twice. The five layers between a visitor and your database, what each stores, and how to set them.
- Choosing web hosting for speed: what to look for
Shared, VPS, managed WordPress, cloud and static hosting compared for speed, what really decides server response time, and how to test a host.
- How to reduce server response time (TTFB)
A slow first response holds back every speed number. How to find where your server loses time, and the fixes in order: cache, database, outside calls, capacity.
- HTTP caching headers: Cache-Control, ETag and more
Every header that controls caching, in plain words: Cache-Control, ETag, Last-Modified, Vary and Age. What each one does, how to set it, and how to test it.
- Back/forward cache: making the Back button instant
The back/forward cache keeps a whole page in memory so Back and Forward are instant. What blocks it, how to test your pages, and how it changes your numbers.
- Text compression: gzip, Brotli and Zstandard
Text compression shrinks HTML, CSS and JavaScript before they travel. How gzip, Brotli and Zstandard compare, how to check yours, and how to switch it on.
- What is a CDN and do you need one?
A CDN keeps copies of your site on servers worldwide so visitors load it from nearby. What it speeds up, what it cannot fix, and how to tell if you need one.
- HTTP/2 and HTTP/3: what changed and how to enable them
HTTP/2 and HTTP/3 let a browser fetch many files at once and cope better with lost packets. What changed, how to check your site, and how to switch them on.
- Connection setup: what happens before the first byte
Before a page loads, the browser finds an address, opens a connection and secures it. Each step is a round trip. How many there are, and how to cut them.
- DNS speed: how name lookups affect your site
Every new host name costs a DNS lookup. What a lookup involves, why it is sometimes slow, and how to shorten it with fewer hosts, a fast provider and good TTLs.
- HTTPS and TLS speed: keeping the cost small
HTTPS adds a secure handshake to each new connection. Where that time goes, and how TLS 1.3, one clean redirect, HSTS and a nearby server keep it small.
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