What is the difference between JSON and CSV?

JSON is a plain-text data format that stores nested objects and arrays. It is the standard payload format for web APIs, readable in any text editor, and parsed natively by every major programming language. CSV is a plain-text table format: one row per line, fields separated by commas, usually with a header row. It is the most widely supported data format there is, readable by every spreadsheet, database and analytics tool.

Will I lose anything converting JSON to CSV?

CSV holds a single flat table with no type information, so nesting is flattened and every value arrives as text. If your source has structure worth keeping, JSON or Parquet will preserve it and CSV will not.

Anything to watch out for with CSV?

CSV has no formal specification, only a convention (RFC 4180). Delimiters, quoting and line endings vary between producers. Leading zeros and long numeric strings are frequently mangled by spreadsheet applications on import — a ZIP code of 01234 becomes 1234.

How is nested data handled?

CSV is strictly flat, so nested objects and arrays have to be flattened into columns or serialised into a single cell. If your data is deeply nested, CSV will lose its shape — JSON, YAML or Parquet are better targets.

What should I know about starting from JSON?

JSON has no comment syntax. Anything stripped from a JSONC or JSON5 source is gone. More broadly: JSON is the default interchange format for web APIs and configuration. It represents nested objects and arrays as plain text, with six value types: string, number, boolean, null, object and array.

When is CSV the right choice?

CSV suits: moving tabular data between tools that share nothing else; bulk import and export; large flat datasets where JSON's repeated keys would dominate. It is the wrong choice when nested or hierarchical data.

Is there a file size limit?

No hard limit — the constraint is your browser's memory. Files under 50MB convert in a few seconds. Larger files work but take longer, and a browser tab typically has 250-500MB to play with, so very large batches are better split into smaller groups.

Does this work on mobile?

Yes. The drop zone falls back to your phone's file picker, and the conversion runs on-device exactly as it does on desktop. Large files are slower on a phone because there is less CPU and memory available, but nothing about the workflow changes.

Convert JSON to CSV

Flatten a JSON array into CSV columns for spreadsheets and analytics tools. Free, in your browser, no upload.

Drop data files to convert

JSON, YAML, XML, CSV, Parquet

Files stay on your device. Open DevTools' Network tab to verify.

Overview

Why convert JSON to CSV

CSV is the more practical choice here. Moving tabular data between tools that share nothing else

Comparison

JSON vs CSV: what actually differs

JSON compared with CSV across encoding, fidelity, file size and support.
Attribute	JSON	CSV
Full name	JavaScript Object Notation	Comma-Separated Values
Encoding	Text — editor-readable	Text — editor-readable
What it preserves	Preserves nesting and value types exactly	Flat only — no nesting, no types, no formatting
Typical size	Verbose — keys repeat on every record	Very compact for tabular data
Support	Native in every programming language and every browser.	Universal. Every spreadsheet, database and BI tool imports it.

How to

How to convert JSON to CSV

01
Drop your JSON file
Drag one or more JSON files onto the drop zone above, or click to browse. Files stay on your device — there is no upload step. data formats can't be reliably identified from their bytes alone, so the extension is used to work out the source format.
02
Convert to CSV
convert.now parses the JSON and writes it out as CSV in a Web Worker, so the page stays responsive even on large files. Nothing is sent anywhere.
03
Download the result
Download the CSV file, or a zip of all of them for a batch. Filenames are preserved, with the extension changed to .csv.

Why here

Why convert.now

Private
Files stay in your browser. No upload step. Nothing for anyone to see.
Fast
No queue, no upload wait. Conversion starts the moment you drop a file.
Free
No ads. No file-count limit. No sign-up wall. Just the converter.

FAQ

JSON to CSV: common questions

No. The JSON to CSV conversion runs entirely in your browser. Files never leave your device, and there is no server involved in the conversion at all. Open DevTools' Network tab and run a conversion if you want to confirm it — you will see the page and its code load, and no request carrying your file.

Related JSON converters

Last updated 27 August 2026

Why convert JSON to CSV

JSON vs CSV: what actually differs

How to convert JSON to CSV

Drop your JSON file

Convert to CSV

Download the result

Why convert.now

JSON to CSV: common questions

Related JSON converters