HTTP 425 Too Early vs 429 Too Many Requests
Both HTTP 425 (Too Early) and 429 (Too Many Requests) belong to the 4xx Client Error category. 425 indicates that the server is unwilling to risk processing a request that might be replayed. Used with TLS 1.3 early data (0-RTT). Meanwhile, 429 means that the user has sent too many requests in a given time (rate limiting). The response should include a Retry-After header.
Description
The server is unwilling to risk processing a request that might be replayed. Used with TLS 1.3 early data (0-RTT).
When You See It
When a server rejects a request sent as TLS 1.3 early data due to replay risk.
How to Fix
Retry the request after the TLS handshake completes.
Description
The user has sent too many requests in a given time (rate limiting). The response should include a Retry-After header.
When You See It
When hitting API rate limits or making too many requests too quickly.
How to Fix
Check the Retry-After header. Implement exponential backoff. Consider caching responses.
Key Differences
HTTP 425: The server is unwilling to risk processing a request that might be replayed. Used with TLS 1.3 early data (0-RTT).
HTTP 429: The user has sent too many requests in a given time (rate limiting). The response should include a Retry-After header.
You encounter 425 when when a server rejects a request sent as TLS 1.3 early data due to replay risk.
You encounter 429 when when hitting API rate limits or making too many requests too quickly.
When to Use Which
For 425 (Too Early): Retry the request after the TLS handshake completes. For 429 (Too Many Requests): Check the Retry-After header. Implement exponential backoff. Consider caching responses.