CSV to JSON Converter
Turn a spreadsheet export into a clean JSON array, with the delimiter detected for you and quoted fields handled correctly.
Your data stays on your device
Input — CSV
- characters
- 0
- lines
- 0
- size
- 0 B
Output — JSON
- characters
- 0
- lines
- 0
- size
- 0 B
Options
Off by default: it would turn the identifier 007 into the number 7.
About this tool
Real CSV files are messier than the format suggests. Exports arrive semicolon-separated, wrapped in quotes, containing embedded newlines, prefixed with a byte order mark, and using any of three line-ending conventions. A parser that only splits on commas fails on most of them.
This converter sniffs the delimiter from the first rows, strips a BOM if present, normalises line endings, and honours RFC 4180 quoting so a field containing a comma or a newline survives intact.
How to use this tool
- Paste CSV text or upload a .csv file — drag and drop works too.
- Leave the delimiter on auto, or pick comma, semicolon, tab or pipe explicitly.
- Choose whether the first row is a header, and whether to infer numbers and booleans.
- Press Convert and copy or download the JSON array.
Key features
- Automatic delimiter detection with a manual override
- First row as header, or generated column names
- RFC 4180 quoting, including escaped quotes and embedded newlines
- UTF-8 BOM stripped automatically
- CRLF, LF and CR line endings all accepted
- Optional inference of numbers, booleans and empty values as null
Example
Input — CSV
name,role
"Chen, Li",admin
Ada,editorOutput — JSON
[
{ "name": "Chen, Li", "role": "admin" },
{ "name": "Ada", "role": "editor" }
]Good to know
- Type inference is heuristic. Identifiers with leading zeros or long numeric strings are safer left as text.
- Rows with more fields than the header get overflow columns named by index rather than being discarded.
- Multi-sheet spreadsheets must be exported one sheet at a time; CSV has no concept of sheets.
Frequently asked questions
How is the delimiter detected?
The parser scores comma, semicolon, tab and pipe by how consistently each produces the same field count across the first rows, and picks the clear winner. Override it manually if your data defeats the heuristic.
Why are my numbers strings?
Type inference is off by default because it is lossy — it would turn the postcode 01234 into 1234. Enable it when you know the columns are genuinely numeric.
What happens to empty cells?
By default they become empty strings. You can switch to null, or omit the key entirely, in the options panel.
Does it handle files exported from Excel?
Yes. BOM handling, CRLF line endings and semicolon delimiters — the three things Excel commonly emits — are all covered.
Your data stays on your device
Your data is processed locally in your browser and is not uploaded to our server. This page keeps working after you go offline, because there is nothing to send.