CSV ↔ JSON Converter
Convert CSV to JSON objects or arrays, or export JSON as CSV. Quotes, line breaks inside cells, and UTF-8 BOM are supported, and pasted data and files never leave your browser.
Local processing · No server upload · Input up to 10 MB · Up to 100,000 rows
How to use
For CSV → JSON, an array of objects uses the unique headers in the first row as object keys. An array of rows returns each row as an array of strings.
JSON → CSV supports arrays of objects and arrays of rows. Nested arrays and objects are written as JSON strings, numbers and booleans become text, and null becomes an empty cell.
Formula protection prefixes cells starting with =, +, -, or @ with an apostrophe. Turn it off only for trusted data when exact round trips are required.
Frequently asked questions
Is CSV or JSON data sent to a server?
No. Pasted content and selected files are processed only in your browser and are not uploaded to a server.
Are numbers and dates in CSV converted automatically?
No. Every CSV cell stays a string so its meaning is not changed.
Does it handle quotes and line breaks inside cells?
Yes. It handles double-quoted cells, escaped double quotes, commas, and line breaks inside cells.
Practical example and verification criteria
CSV ↔ JSON Converter: First identify whether the source is plain text, a URL component, JSON, CSV, CSS, JavaScript, a color, or a token, then check character encoding, delimiters, quoting, and line-ending rules. Encoding is not encryption, decoding is not signature verification, and minification is not code optimization; define the required output format and destination before running the tool.
CSV ↔ JSON Converter: For a quick check, start with name,score\nA,10 ↔ [{name:A,score:10}] as a small input whose result relationship you can verify directly. Confirm that the input summary, units, and options match your intent before applying the tool to real values or a copy of the source; this reduces setup mistakes.
CSV ↔ JSON Converter: Put the output into the target browser, build tool, API, or design surface and check for parsing errors or changed meaning. Decoding does not prove authenticity, a hash cannot be decrypted, and minified code is not guaranteed to behave like the source. Preserve the original and tests, and avoid entering passwords, tokens, or personal data.
CSV ↔ JSON Converter · Work record: For real work, record the input conditions, selected options, and result together. Do not assume the same state will remain after a refresh or device change. Preserve important results separately using copy, download, a screenshot, or another method the page supports, then reopen them in the target environment.
CSV ↔ JSON Converter · Error check: If an error or unexpected result appears, reduce the input, run again with default options, and then change one condition at a time. Recording error messages and boundary values helps distinguish format issues, unsupported cases, and browser resource limits, and prevents an empty result from being mistaken for success.
CSV ↔ JSON Converter · Scope of use: Check the page guidance for browser processing versus server lookup, storage location, and supported scope. Use sensitive source material or secrets only when strictly necessary. High-impact work such as legal, financial, or medical decisions or changes to an operational system requires current authoritative information and a separate verification process.