Quick answer
Netlify documents buffered and streamed payload as 6 MB buffered; 20 MB streamed; 256 KB background. Binary payloads can reach the buffered limit at roughly 4.5 MB before base64 expansion.
Verified Aug 22, 2026Official source
Current limits
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| buffered and streamed payloadBinary payloads can reach the buffered limit at roughly 4.5 MB before base64 expansion. | 6 MB buffered; 20 MB streamed; 256 KB background | Function-type specific | NetlifyAug 22, 2026 |
Why does this limit matter?
Changing to background execution dramatically reduces the allowed request payload.
This value is scoped to Function-type specific; a different plan, runtime, model, endpoint, region, or account can produce a different effective constraint.
What should you check?
- Measure transmitted and encoded size and verify the function type.
- 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
- Encoding and the platform's buffering or streaming path determine effective bytes.
- 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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