JSON to CSV

How JSON to CSV works

Convert an array of JSON objects into CSV, with quoted fields for commas, quotes and newlines. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

From objects to columns

The input is expected to be an array of objects. Keys become the header row, and each object becomes a row. Keys are collected across all objects, so an object missing a field simply leaves that cell empty rather than shifting the columns.

Nested objects are serialised with JSON.stringify into the cell rather than flattened. That keeps the data intact and keeps the output honest — a flattened version would invent column names you never chose.

Quoting and delimiters

Any value containing the delimiter, a quote or a newline is wrapped in double quotes, and inner quotes are doubled. That is the RFC 4180 rule, and it is what makes the output survive Excel, Sheets and a naive SQL loader.

Comma, semicolon and tab are offered because European locales often use the semicolon as the list separator — a CSV with commas opens as a single column on those systems.

What it will not do

It does not flatten deeply nested arrays into a wide table, and it does not infer types — every cell is text, which is why a phone number keeps its leading zero and a date stays as written.

If the input is a single object rather than an array, wrap it in brackets first. One object has no rows to speak of, and the tool will say so.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions