HTTP/2 frequently asked questions
What is HTTP/2?
HTTP/2 is a new version of HTTP protocol. It’s goal is to improve website performance by optimizing how HTTP is transferred "on-the-wire". It doesn’t change the semantics of HTTP, which means that HTTP headers, status codes, etc. work exactly the same way as in HTTP/1.
What are the key performance improvements?
- HTTP/2 protocol is multiplexed which means that multiple requests can use the same TCP connection and thus website assets can be requested in parallel. HTTP/1, in contrast, requires each request to use its own TCP connection and thus website assets are requested sequentially.
- HTTP/2 protocol allows browser to use stream priority mechanism. Stream priority mechanism is a mechanism for browsers to load HTML content for a web page first, followed by CSS, then JavaScript, and finally images. This allows browsers to render web pages quickly.
- HTTP/2 protocol automatically compress HTTP headers. This reduces the amount of data that needs to be transferred between a browser and a server.
- HTTP/2 protocol allows servers to push responses proactively into viewer's browser cache instead of waiting for viewer to request it.
- HTTP/2 protocol is binary, instead of textual. Binary transfer is more effective "on-the-wire" than textual.
- Other HTTP/2 improvements can be found here.
Does CDNsun support HTTP/2?
Yes, CDNsun supports HTTP/2 protocol. All our CDN Static / CDN Static Push services are compatible with HTTP/1.0, HTTP/1.1 and HTTP/2 (equivalently HTTP/2.0) protocols.
Which browsers support HTTP/2?
A list of browsers that support HTTP/2 protocol can be found on caniuse.com.
What if viewer's browser doesn't support HTTP/2?
If viewer's browser doesn't support HTTP/2 protocol then our CDN edge server will automatically communicate with the browser over HTTP/1 protocol.
Does HTTP/2 require SSL?
HTTP/2 protocol does not require SSL encypted connection, but all current browsers support HTTP/2 protocol only for SSL encrypted connections. It means that to use HTTP/2 protocol you must use a CDN service with SSL enabled and integrate it over https:// scheme.
What Next?
Check out our HTTP/2 speed test.