ServerChrome · Edge
ERR_HTTP2_PROTOCOL_ERROR

HTTP/2 Protocol Error

The server sent an HTTP/2 response that violated the protocol spec. This is a server-side bug or configuration issue.

Why this happens

  • Bug in the server's HTTP/2 implementation
  • Load balancer and origin server have mismatched HTTP/2 settings
  • A proxy or CDN is improperly terminating HTTP/2
  • Server sent invalid HPACK headers
  • Corrupted network state in your browser

How to fix it

  1. 1

    Hard refresh the page (Ctrl+Shift+R)

  2. 2

    Clear your browser cache completely

  3. 3

    Try in a private window

  4. 4

    If managing the site, check your reverse proxy's HTTP/2 config

Diagnose it faster

Use our free tools to check whether the issue is on your end or the server's:

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