CSV to JSON Converter
Convert CSV to JSON (array of objects with typed values) and JSON back to CSV. Handles quotes, commas in fields, and nested keys. Local, free.
CSV to JSON sounds trivial until the data contains commas inside quoted fields, embedded newlines, and numbers that must stay numbers rather than strings. This converter handles RFC 4180 quoting properly and outputs an array of objects keyed by the header row.
Type detection is optional — keep everything as strings for a faithful copy, or let numbers and booleans convert. The reverse direction (JSON to CSV) flattens nested objects with dot-notation keys for spreadsheet use. All local, no upload.
100% in-browser · no upload · no signup · nothing you paste or drop here leaves your device
CSV ↔ JSON Converter
Convert between CSV and JSON with custom delimiters. 100% local.
This tool runs 100% in your browser. All computation happens locally on your device — your input is never uploaded to any server. Results are for reference only.
CSV rows vs JSON tree — what conversion really means — illustrated
CSV is a flat table: one header row names the columns, every following line is one record with the same fields. JSON is a nestable tree: objects can hold objects and arrays, so it can express repeats, nesting and blank fields that a grid cannot. Converting CSV → JSON turns each row into an object keyed by the header; JSON → CSV flattens those objects back into rows. When a JSON field nests deeper, its path becomes part of the column name so nothing is lost.
Three rows × three columns map cleanly to an array of three objects. runtimes, units and modes are straight 1:1 — that is the entire job of the converter, done locally.
The same three contacts, kept as a grid in CSV and as objects in JSON.
- Header becomes keys:Every CSV column name turns into a JSON property on each row object
- Rows become objects:Each data line is one object — the array is the whole table
- Blank & repeated cells:Empty cells map to null; JSON covers them with key/undefined naturally
- Reversing it:JSON → CSV flattens the array back to rows — dotted paths flatten nested structures
About this CSV to JSON converter
This page covers convert csv to json online, json array of objects from csv, csv parser online, json to csv export free — all the same underlying task as CSV to JSON converter. The tool above is FreeToolHub's csv json embedded in full: every feature works right here, and nothing you process is uploaded to any server.
Frequently asked questions
How do I convert a CSV file to JSON objects?
Paste the CSV or drop the file; the first row becomes the object keys and each subsequent row becomes one object in the output array. Choose type inference if you want numbers as numbers — otherwise everything stays as strings, which is safer for IDs and zip codes with leading zeros.
Why does my CSV with commas in values break converters?
CSV allows commas inside fields if the field is double-quoted, and quotes inside fields are escaped by doubling — parsers that ignore these rules corrupt rows silently. This converter implements the full RFC 4180 rules, so "Smith, Jr.", "she said ""hi""" and multi-line quoted fields all parse correctly.