425 Too Early — Causes & Fix
HTTP 425 (Too Early) means the server is unwilling to process a request that might be replayed — sent as part of TLS 1.3 "early data" (0-RTT).
- Applies to
- Any website or web server (HTTP standard)
- Time to fix
- 5–30 minutes
What it means
Occurs with TLS 1.3 0-RTT when a client sends data too early and the server wants to avoid replay attacks. HTTP status 425 is defined in RFC 9110 (HTTP Semantics). This is a client-side (4xx) error — the request itself had a problem, so the fix is usually on the requester's side or in how the server validates the request.
Symptoms
- "425 Too Early" on some HTTPS requests
- Intermittent with 0-RTT enabled
How to fix it
- 1
Retry without early data
1. The client should retry the request after the TLS handshake completes (not as early data).
- 2
Adjust 0-RTT (developers)
1. Disable 0-RTT for non-idempotent requests, or ensure the client retries on 425.
Frequently asked questions
What is 425 about?
It relates to TLS 1.3 0-RTT "early data." The server rejects potentially replayable early data; the client should resend normally.
Last updated July 20, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.