CSV to JSON — Free, in Your Browser
Half of data work is format hand-off: the spreadsheet export arrives as CSV, the API wants JSON.
CSV ↔ JSON Converter
Both directions — 100% local
Why convert CSV to JSON
Half of data work is format hand-off: the spreadsheet export arrives as CSV, the API wants JSON. The standard "paste into a website converter" route means pasting whatever that CSV contains — often customer emails, order rows, internal notes — into a form on someone else's server. This converter parses in your tab instead, so a production data export never crosses your network.
The parser follows real CSV rules: quoted fields containing commas, newlines inside quotes, and escaped quotes all come through intact. The header row becomes the keys of each object; you get a clean JSON array back.
How to do it (3 steps)
- Paste your CSV or load the file — parsed locally.
- Review the generated JSON array (one object per row).
- Copy or download the JSON.
Technical note
Numbers that look numeric (including negatives, decimals and exponent notation) are emitted as JSON numbers; everything else stays a string. Empty cells become empty strings, not null — a deliberate choice that matches what most API consumers expect. If you need a different shape (an array of arrays, or an object keyed by a column), tell us; the array-of-objects form is the one 90% of workflows want.
The mistake worth avoiding
The common mistake is pasting a CSV that is actually a semicolon-separated export — common for spreadsheets saved in European locales — and getting one giant column out of it. Check the first line before pasting: if the values are separated by semicolons rather than commas, re-export with comma separators or swap in your editor first. The second classic: a CSV with an empty header cell, which produces objects with a blank key. Fix the header before converting, not the JSON after.
FAQ
- Is my CSV uploaded? No — parsing and serialisation happen in your browser. The file content never leaves the device.
- How are quoted fields handled? Properly — commas and newlines inside quotes are preserved, which is where naive splitters break.
- What about dates? Dates stay as the strings they are in the CSV. JSON has no date type, so formatting is left to you on either side.
- What file encodings are supported? The parser reads what the browser hands it, detected from the bytes — UTF-8 and common legacy encodings work. If you see mojibake, the file is in a legacy encoding; open it in an editor, re-save as UTF-8, and paste again.