CSV to JSON Schema converter
Convert CSV to JSON Schema: a schema for the rows of a CSV file, with each column typed from its values.
What you get
- Generate JSON Schema from CSV: a JSON Schema from CSV rows, with each column typed from its values.
- Columns with values like 007 or 1.50 stay strings, so the schema matches the data exactly.
- Checked: every row validates against the schema with Ajv.
- A CSV schema generator: one schema for every row, to validate CSV rows before an import.
- Private and free: everything runs in your browser, nothing is uploaded, and there is no sign-up.
How each result is checked
- Step 1: The CSV is parsed with a strict parser that reports broken quotes.
- Step 1: Every cell in the JSON is compared with the original cell text; nothing may change.
- Step 2: The generated schema is compiled with Ajv, the most widely used JSON Schema validator.
- Step 2: Your sample is validated against the generated schema. It must pass.
What can't convert exactly
- Number detection only converts values whose text stays identical, so 007, 1.50 and very long IDs stay text.
- Duplicate or empty header names are renamed, with a warning.
- A schema inferred from one sample can only describe what the sample shows. Review required fields and enums before relying on it.
- Turn on "Top-level array = list of samples" to infer one schema from many records.
Questions
How is a two-step conversion checked?
Your input is converted to JSON first, then to the target format. Each step has its own independent check, and both must pass. The checks of both steps are listed under every result.
Is my data uploaded?
No. Everything runs in your browser, in a background worker. Nothing is sent to a server.
How do I convert CSV to JSON Schema online?
Paste your CSV or open a file on the left (or click Example). The JSON Schema appears on the right as you type, already checked. Copy it, or download it as a file. Nothing is uploaded.
Can the JSON Schema output be wrong?
Every result is checked before it is shown (the checks are listed on this page). If a check fails, the page says "Review needed" and why, instead of presenting the output as correct, and anything that cannot convert exactly is named in the notes.