HTTP Version

What It Does

Checks HTTP/3 support by parsing the Alt-Svc response header. Infers HTTP/2 support for HTTPS connections (Cloudflare Workers cannot verify ALPN negotiation directly). Reports the detected protocol version and identifies available upgrade paths.

Why It's Useful

HTTP/2 (RFC 9113) and HTTP/3 (RFC 9114) provide significant performance improvements through multiplexing, header compression (HPACK/QPACK), and 0-RTT connection establishment. HTTP/3 over QUIC (RFC 9000) eliminates head-of-line blocking at the transport layer. Verifying support is important for performance optimization and ensuring CDN/load balancer configuration is correct.

Use Cases

Parameters

Response Fields

Code Examples

curl "https://api.edgedns.dev/v1/domain/http-version" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d "domain=google.com"

const response = await fetch(
  'https://api.edgedns.dev/v1/domain/http-version?domain=google.com',
  {
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY'
    }
  }
);

const data = await response.json();
console.log(data);

import requests

response = requests.get(
    'https://api.edgedns.dev/v1/domain/http-version',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={
    'domain': 'google.com'
    }
)

data = response.json()
print(data)

Related Endpoints

External References

Learn more about the standards and protocols behind this endpoint.