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Input
YAML
Limit
1 MiB
Runtime
Browser

Validate YAML data against a bounded JSON Schema

Check parsed YAML values against a separately supplied JSON Schema and return structured instance paths for each supported violation.

Local processingNo sign-upNo content logging

Validate against schema

Inputs are limited to 1 MiB and stay in this browser tab.

Paste or edit the source. Tool Swim does not upload or save it.

Paste a bounded schema. Remote references and unsupported high-complexity keywords are rejected.

Schema validation report

Nothing is placed in a URL, account, preset, or remote log.

What this tool does

Strict, bounded, local processing

Schema validation begins only after the YAML parses. The local engine supports a documented bounded subset and rejects remote references or excessive combinatorial complexity.

Syntax and schema answer different questions

YAML parsing identifies mappings, sequences, and scalar values. JSON Schema can then require properties, constrain types and ranges, and reject unexpected members for a particular contract.

Diagnostics use instance paths so a failing value can be found without copying document content into an error message or telemetry event.

The supported subset is part of the contract

Remote references, recursive graphs, regex-heavy constraints, and uncontrolled combinatorial keywords can create network or resource risks. Unsupported schema features fail explicitly rather than being ignored.

Primary references

Questions and answers

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