Quick answer
Azure Functions documents language worker startup as 60 seconds. The worker process must start and initialize within the documented window.
Verified Aug 22, 2026Official source
Current limits
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| language worker startupThe worker process must start and initialize within the documented window. | 60 seconds | All hosting plans | MicrosoftAug 22, 2026 |
Why does this limit matter?
Large dependencies and blocking module initialization can fail before user code handles a request.
This value is scoped to All hosting plans; a different plan, runtime, model, endpoint, region, or account can produce a different effective constraint.
What should you check?
- Profile package load and startup initialization separately from handler duration.
- 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
- Cold-start latency and worker startup failure are not the same as function execution timeout.
- 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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