Quick answer
Azure Functions documents http load-balancer response ceiling as 230 seconds. The HTTP response cap applies even when the hosting plan permits longer background execution.
Verified Aug 22, 2026Official source
Current limits
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| HTTP load-balancer response ceilingThe HTTP response cap applies even when the hosting plan permits longer background execution. | 230 seconds | HTTP-triggered functions | MicrosoftAug 22, 2026 |
Why does this limit matter?
An unbounded functionTimeout does not make a synchronous HTTP request wait indefinitely.
This value is scoped to HTTP-triggered functions; a different plan, runtime, model, endpoint, region, or account can produce a different effective constraint.
What should you check?
- Measure time to first final response and design long work around a durable status endpoint.
- Confirm the exact plan, model, runtime, endpoint, region, and account that serve the failing workload.
- Record the observed value, response headers or configuration, timestamp, and source without logging secrets.
Important caveats
- Use asynchronous patterns for work that intentionally exceeds the load-balancer window.
- Treat the official source and live account configuration as authoritative if they differ from this verified snapshot.
HyperObserve reports the documented platform constraint. Your application, SDK, gateway, provider, region, or account can impose a lower effective limit.
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