Too Early
4xx Client Error
Last updated:
The server is unwilling to risk processing a request that might be replayed (used with TLS 0-RTT).
Description
Introduced for TLS 1.3 early data. Prevents replay attacks on non-idempotent operations sent before the handshake completes.
When to use
Only relevant if you handle TLS 1.3 early data at the application layer.
Specification
RFC 8470
Examples
HTTP response
HTTP/1.1 425 Too Early
Content-Type: application/json
{"error":"Too Early"}Node.js (Express)
res.status(425).json({ error: "Too Early" });Go (net/http)
w.WriteHeader(http.Status425)
Python (Flask)
return jsonify({"error": "Too Early"}), 425All 4xx codes
400 Bad Request401 Unauthorized403 Forbidden404 Not Found405 Method Not Allowed406 Not Acceptable408 Request Timeout409 Conflict410 Gone411 Length Required412 Precondition Failed413 Payload Too Large414 URI Too Long415 Unsupported Media Type418 I'm a teapot422 Unprocessable Entity425 Too Early428 Precondition Required429 Too Many Requests431 Request Header Fields Too Large451 Unavailable For Legal Reasons