Flat JSON to CSV
Convert a nonempty array of up to 10,000 flat objects into quoted CSV with the union of keys as headers. Up to 100 columns and four million output characters are supported; nested values are rejected.
How to use Flat JSON to CSV
- Enter or paste “JSON array of flat objects”. Follow the separators and formatting described in the tool introduction.
- Select Calculate or Process. Review the result and any validation message before copying or downloading available output. Reset clears the result and restores the starting inputs.
Method & assumptions
Gather keys in first-seen order; serialize scalar cells with doubled quotes and CRLF rows; prefix formula-like spreadsheet cells with an apostrophe.
Worked example
Two objects with name and score produce a header and two quoted data rows, available as data.csv.
Results and projections are informational estimates, not financial, medical, legal, tax, or property advice. Check assumptions, units, rounding, and local requirements independently. Investment illustrations do not guarantee returns. Keep original files and check transformed output before use.
Questions, answered
Why are some cells prefixed with an apostrophe?
Formula-like values and suspicious leading controls receive an apostrophe to reduce spreadsheet formula injection risk. Review downloads before opening in a spreadsheet. Null and missing values become empty cells; negative numbers are also protected as text.
Does this send my input to a server?
No. This engine processes input locally without network requests. The surrounding website may have its own analytics or scripts; avoid entering sensitive material on an untrusted site. Text fields accept at most 1,000,000 UTF-16 units unless a smaller field limit is stated.