Microtool
SchemaFirst
CSV → JSON you can actually ship
Schema-aware CSV → JSON conversion with type inference, confidence scoring, and strict validation. 100% browser-only.
What it does
- Typed JSON output
- Inferred schema with confidence per column
- Warnings for mixed types, empty-heavy columns, and invalid values
- Clean vs Strict outputs
- Export Clean JSON, Strict JSON, or schema
- 100% browser-only
How it works
1) Paste CSV
Paste your CSV text into SchemaFirst (no file upload required).
2) Review schema
See inferred types and confidence scores per column.
3) Export JSON
Download Clean JSON, Strict JSON, or the full schema.
Screenshot
FAQ
Is my CSV data uploaded anywhere?
No. SchemaFirst runs locally in your browser. Files never leave your machine.
Does this require installation?
No. It's a simple offline tool—download, unzip, and open.
What's the difference between Clean and Strict JSON?
Clean keeps all rows; invalid values are coerced to null. Strict drops rows with schema violations; reports dropped row indices.
Frosted//Logic site — v6.00