Template exceeds a CloudFormation size or count quota

WHAT IT MEANS

What this error means

• Value at 'templateBody' failed to satisfy constraint: Member must have length less than or equal to 51200 — the template body was passed inline, and the inline limit is 51,200 bytes. Via S3, the ceiling is 460,800 bytes.
• Template format error: Number of resources, ..., is greater than maximum allowed — a count quota (resources cap at 500 per stack).
• ... may not exceed ... bytes — the S3-path size ceiling.

FIX

How to fix it

1. Submit through S3 instead of inline. That alone raises the body ceiling from 51,200 to 460,800 bytes. sam deploy with a resolved bucket does this automatically; direct CLI calls should use --template-url rather than --template-body.
2. Measure the rendered template — the post-transform output, not your source file. SAM templates expand considerably through the transform.
3. Split very large stacks with nested stacks when a count quota is the limit; each nested stack gets its own resource budget.
4. Check the quotas page for the specific limit named in the error before restructuring — some quotas are adjustable, most template-shape ones are not.

AUTOMATE THE TRIAGE

Diagnose this automatically

SAM Doctor matches the quota wording (medium confidence) and keeps ordinary validation errors with the generic change-set rule. Runs locally; no AWS access, no log upload.

python -m pip install sam-doctor
sam-doctor diagnose deployment.log --format markdown

RELATED

Related errors

• InvalidSamDocumentException (schema validation) — the other pre-resource template rejection.
• No changes to deploy — a different way a change set ends before doing anything.