Problem
My domain reeflocal.io (attached to a Vite project) is serving all assets over HTTP/1.1 without Brotli/gzip compression.
Verification
curl -I --http2 https://reeflocal.io
Returns HTTP/1.1 200 OK instead of expected HTTP/2 200
Configuration
- Using Vercel nameservers (
ns1.vercel-dns.com, ns2.vercel-dns.com)
- DNS resolves to correct Vercel IPs
SSL is valid
Impact
Lighthouse reports 3+ seconds of recoverable render-blocking time due to missing HTTP/2 multiplexing and compression.
Is there a way to ensure HTTP/2 and compression are applied?
pawlean
(Pauline P. Narvas)
5
Welcome to the Vercel Community!
Cool project 
Vercel’s CDN supports HTTP/2 through ALPN negotiation. When testing with curl, try:
curl -I --http2-prior-knowledge https://reeflocal.io
The results are:
HTTP/2 200
accept-ranges: bytes
access-control-allow-origin: *
age: 69
cache-control: public, max-age=0, must-revalidate
content-disposition: inline
content-type: text/html; charset=utf-8
date: Fri, 17 Apr 2026 11:08:08 GMT
etag: "4b264812b229d2b3a2943254c19261d8"
last-modified: Fri, 17 Apr 2026 11:06:58 GMT
server: Vercel
strict-transport-security: max-age=63072000
x-vercel-cache: HIT
x-vercel-id: lhr1::29hdk-1776424087993-d123805054ce
content-length: 9145
For Brotli/gzip compression, include the Accept-Encoding header:
curl -H "Accept-Encoding: gzip, br" -I https://reeflocal.io
I can see:
HTTP/2 200
access-control-allow-origin: *
age: 108
cache-control: public, max-age=0, must-revalidate
content-disposition: inline
content-encoding: br
content-type: text/html; charset=utf-8
date: Fri, 17 Apr 2026 11:08:46 GMT
etag: W/"4b264812b229d2b3a2943254c19261d8"
last-modified: Fri, 17 Apr 2026 11:06:58 GMT
server: Vercel
strict-transport-security: max-age=63072000
x-vercel-cache: HIT
x-vercel-id: lhr1::f8fq6-1776424126886-571b3cb5b9a5
If you’re behind a proxy, it might downgrade connections to HTTP/1.1. Test from a different network to confirm!