JSON Validator vs JSON Schema Lite — Which Should You Use?
Both look at JSON and tell you if something's wrong, but they're answering different questions. The Validator checks the grammar: is this even valid JSON? Schema Lite checks the shape: does this valid JSON match the structure I expect? You validate syntax first, then validate against a schema. Both run 100% in your browser.
Use the Validator when
- You're not sure the JSON is syntactically valid and want a definitive yes or no.
- Something threw a parse error and you need the exact line and column.
- You want to catch trailing commas, unquoted keys, and single quotes before they bite.
- You just need to know 'does this parse?' before anything else.
Use Schema Lite when
- The JSON parses fine, but you need to confirm it has the fields and types you expect.
- You're checking an API response or config against a known shape.
- You want to require certain keys and validate their types (string, number, object…).
- You're catching 'valid JSON, wrong structure' bugs, the kind a syntax check can't see.
Side by side
| JSON Validator | JSON Schema Lite | |
|---|---|---|
| Primary job | Confirm JSON is syntactically valid | Confirm JSON matches an expected shape |
| Question it answers | 'Does this parse?' | 'Does this have what I expect?' |
| Needs a schema? | No, one input | Yes, JSON + schema |
| Catches syntax errors | Yes, exact line + column | No, assumes valid JSON |
| Catches missing / wrong-typed fields | No | Yes |
| Where it runs | Browser, no upload | Browser, no upload |
Schema Lite is deliberately a lightweight subset (type checks, required keys, and nested structure), not the full JSON Schema spec. It assumes its input is already valid JSON; run the Validator first if you're unsure. A full JSON Schema Validator is on the roadmap.
Validate syntax first, then validate shape. The Validator tells you the JSON parses; Schema Lite tells you it's the JSON you were expecting. A payload can pass one and fail the other. Valid syntax with a missing required field, or the right shape that's one brace short.