JSON to CSV
Flatten a JSON array into spreadsheet-ready CSV — free, in your browser.
About this converter
Paste a JSON array of objects, get CSV with a header row built from every key that appears anywhere in the data — objects missing a field simply get an empty cell, so ragged API responses convert cleanly. Quoting follows RFC 4180 (commas, quotes and newlines inside values are handled properly), and the download includes a BOM so Excel opens accented characters correctly. Free, no account, converted on your device.
The details that usually go wrong
Three things break naive JSON→CSV conversions, and this tool handles each: values containing commas or quotes (quoted and escaped per the standard), objects with different keys (header is the union, not the first object), and nested structures (kept as JSON strings in their cell rather than silently dropped — flatten them upstream if you need columns). Going the other way, CSV to JSON is the mirror of this tool, and the JSON formatter helps when the input won't parse.
Frequently asked questions
How are nested objects and arrays handled?
They're kept as JSON strings inside their cell — visible and recoverable, rather than silently dropped. If you need them as columns, flatten the data before converting.
Why does Excel show weird characters for accents?
Excel needs a BOM to detect UTF-8 — our download includes one, so accents and non-Latin text open correctly. If you copy-paste instead, use Data → From Text with UTF-8.
What if my objects have different keys?
The header row is the union of all keys in first-seen order, and missing values become empty cells — ragged data converts without losing fields.
Is my data uploaded?
No — the conversion runs in your browser. Free, no account, no size limit beyond your device's memory.