Diagnosing and Resolving HTTP 502 / 1101 Errors

Common Causes of Edge 502 Errors

In Cloudflare Workers, error 1101 indicates an unhandled JavaScript exception thrown in the worker script before returning a Response.

Investigating with Wrangler Logs

Stream real-time production errors using:

wrangler tail --status error

CPU Time Exceeded

Worker execution is bounded by strict CPU wall-clock limits (e.g., 50ms standard CPU time). Heavy synchronous JSON parsing or regex operations can trigger immediate terminations.