InlineDataTooLarge
AWS InlineDataTooLarge (Inline Data Too Large) means inline data exceeds the maximum allowed size. In Amazon S3, this error returns HTTP 400.
Last reviewed: February 4, 2026|Editorial standard: source-backed technical guidance
What Does Inline Data Too Large Mean?
S3 rejects the request before execution when inline fields exceed allowed size limits, so the workflow stalls until payload shape and transfer path are corrected.
Common Causes
- -Inline request content exceeds operation-specific S3 size limits.
- -Large binary or encoded content is embedded in inline fields instead of sent as normal object data.
- -Base64 expansion pushes request size above accepted threshold.
How to Fix Inline Data Too Large
- 1Move oversized content to standard S3 object upload flows (PutObject or multipart) instead of inline request fields.
- 2Enforce operation-specific request-size checks before send.
- 3Retry with reduced inline payload size.
Step-by-Step Diagnosis for Inline Data Too Large
- 1Measure raw and encoded payload size before dispatch.
- 2Check operation size limits in official API docs.
- 3Inspect serializer behavior for accidental payload duplication.
Inline Payload Size Audit
- -Measure serialized payload at each transform stage (example: 7.8 MiB binary expands beyond limit after Base64 encoding).
- -Inspect serializer paths for duplicate/embedded data fields (example: request contains both raw document and encoded document copy).
Reference-Based Transfer Refactor Checks
- -Verify oversized inline content is moved to object upload paths before request submission (example: upload payload first, then send compact metadata-only request).
- -Audit request contracts to enforce maximum inline size ceilings (example: reject payloads > 1 MiB before SDK call).
How to Verify the Fix
- -Re-run request with reduced inline payload and confirm success.
- -Validate referenced-object path works for large data transfer.
- -Confirm inline-size rejection rates drop after rollout.
How to Prevent Recurrence
- -Enforce operation-specific request size limits in clients.
- -Prefer object references over inline blobs for large payloads.
- -Add maximum-size contract tests in CI.
Pro Tip
- -calculate size budgets using post-serialization byte counts (not object length in memory) to catch Base64 and envelope overhead before send.
Decision Support
Compare Guide
HTTP 400 vs 422: Bad Request vs Unprocessable Content
Fix API payload issues faster by using 400 for malformed syntax and 422 for semantic validation failures, so clients correct format before business rules.
Playbook
CORS Error Fix Playbook (Preflight / Origin / Credentials)
Use this playbook to separate browser-enforced cross-origin policy failures from server-side CORS header and route defects and apply strict origin and credential controls safely.
Playbook
Validation Failure Playbook (400 / 422 / INVALID_ARGUMENT)
Use this playbook to separate malformed-request failures from semantic validation failures, then fix request contracts without broad server-side bypasses.
Official References
Provider Context
This guidance is specific to AWS services. Always validate implementation details against official provider documentation before deploying to production.