HTTP/2 is a major revision of the HTTP protocol focused on performance — multiplexing multiple requests over a single connection, header compression, and server push. Technically, the HTTP/2 specification allows it to run without encryption. In practice, no major browser supports HTTP/2 over plain HTTP — they only negotiate it over TLS, using an extension called ALPN during the handshake.
Why browser vendors made that call
This was a deliberate policy decision by browser makers, not a technical requirement of the protocol itself — partly to push HTTPS adoption further, and partly because HTTP/2's more complex connection handling made unencrypted deployment a bigger attack surface in practice.
The practical upshot
If you're on HTTPS with a reasonably modern server, you likely already get HTTP/2's performance benefits automatically, with no separate configuration — most hosting providers and CDNs enable it by default once TLS is active. It's one more concrete reason "HTTPS is slower" is largely outdated: for most real-world sites, the HTTP/2 upgrade that comes bundled with HTTPS more than offsets the small overhead of the TLS handshake itself.
Why this was a deliberate browser policy choice, not a technical requirement
The HTTP/2 specification technically permits operation without encryption, but no major browser actually implements that path — a deliberate policy decision by browser vendors, partly to further incentivize HTTPS adoption and partly because HTTP/2's more complex connection handling was judged a larger attack surface if left unencrypted.
What this means if you're still on plain HTTP
A site still running on HTTP misses out on HTTP/2's real performance benefits entirely, in addition to the trust and security downsides already covered elsewhere — one more concrete, measurable reason migrating to HTTPS tends to be speed-neutral or even speed-positive rather than the performance cost people sometimes assume.
What HTTP/2's multiplexing actually changes about page load behavior
HTTP/2 allows many requests to share a single connection simultaneously rather than requiring separate connections or strictly sequential requests, meaningfully reducing the overhead of loading a page with many separate resources, images, scripts, stylesheets, compared to HTTP/1.1's more limited connection reuse model.
What server push was, and why it's now largely deprecated
HTTP/2 originally included a server push feature letting a server proactively send resources before the client requested them — browser vendors have since deprecated support for it after real-world usage showed it often made performance worse rather than better in practice, illustrating that not every theoretically beneficial protocol feature translates into a real-world win.
How to confirm your own site is actually using HTTP/2
Browser DevTools' Network tab shows the protocol version used for each request, typically labeled h2 for HTTP/2, directly in the request details — a quick, direct way to confirm your server and hosting configuration are actually delivering the benefit rather than assuming it based on your HTTPS status alone.
Why this connection is worth remembering even if the technical details fade
The simple, memorable takeaway is that migrating to HTTPS today often comes with a meaningful performance upgrade bundled in for free, not the performance cost many people still assume based on outdated, decades-old assumptions about encryption overhead.
What a website visitor actually experiences differently with HTTP/2 enabled
Beyond technical benchmarks, an ordinary visitor experiences HTTP/2's benefit as a page that simply feels faster and more responsive, particularly on a page loading many separate images, scripts, and stylesheets — a real, though not always consciously noticed, improvement in everyday browsing experience.
A closing thought
A quick closing thought: the fact that migrating to HTTPS today often comes bundled with a genuine performance upgrade, rather than the performance cost it represented decades ago, is a detail worth actively correcting when you encounter the outdated myth.