JSON & CSV Converter
Move tabular data between JSON and delimited files while reviewing the transformations. Configure headers, nested values, spreadsheet protection and export encoding rather than relying on an opaque conversion.
Browser-based · No account required · Copy and export
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Developer toolsHow to use JSON & CSV Converter
- Paste an array of JSON objects or CSV text, or load a local file. Choose the correct direction and delimiter.
- Set header, flattening and whitespace options. For CSV export, choose line endings, optional BOM and formula-prefix protection.
- Convert and inspect rows and byte counts. Swap the result into the opposite direction or download the selected format.
When to use this tool
Move table-shaped JSON into a spreadsheet or turn CSV rows into records for a script. Review headers, delimiters, nested-value flattening and spreadsheet-formula protection.
JSON structure and spreadsheet cells are different models
CSV contains rows and string fields rather than a complete JSON type system. Nested objects/arrays are serialized into JSON cell strings when not flattened. Flattening creates dot-separated column names and rejects collisions. Formula protection prefixes risky leading characters with an apostrophe; this changes cell text intentionally. A UTF-8 BOM can help some spreadsheet importers identify encoding.
Worked example
JSON: [{"name":"Alex","score":12}]
CSV:
name,score
Alex,12
CSV-to-JSON fields are strings unless another application converts their types.Check identifiers and types before a spreadsheet handoff
Original JSON practice input
[{"id":"0012","quantity":2,"enabled":true}] - Choose JSON to CSV, comma delimiter and a header row. Convert the authored record and inspect all three columns.
- Keep flattening off for this simple record. For nested data, decide whether JSON cell strings or dot-separated columns are appropriate; flattening does not provide a reversible schema.
- Download CSV and use the recipient's text-import controls for the ID column. Even when this converter writes
0012, a spreadsheet can interpret it as a number. - If converting the CSV back, use the same delimiter/header settings and inspect types. CSV fields return as strings, so quantity and enabled do not automatically regain JSON number and boolean types.
- Use trimming only when surrounding spaces are expendable. Review formula protection deliberately because its apostrophe prefixes change the exported text.
This is an authored round-trip inspection exercise, not a generated CSV or proof of lossless conversion. Keep the original JSON as the typed source. Use CSV Editor for table corrections and JSON Schema Validator to check the types in a JSON result against your own supported schema.
Limits and output checks
CSV import does not automatically infer number/boolean types. Trimming can change significant surrounding whitespace. Flattening is not a reversible nested-object mapping. Formula prefixing is a defensive export convention, not a guarantee for every spreadsheet configuration. Keep source data before conversion.
Reference: Papa Parse CSV options.
Frequently asked questions
Can I export tab-separated text?
Choose the Tab delimiter. CSV quoting rules still apply to values containing the selected delimiter or newlines.
Does the BOM appear in JSON output?
No. The optional UTF-8 BOM is added only to the downloaded CSV, not the JSON output or visible field contents.
Why are two flattened columns rejected?
A literal key such as a.b can collide with nested a then b. The converter rejects that ambiguity instead of silently overwriting a value.
A practical workflow
Convert a simple list of records for a table workflow, then inspect column names and representative values before opening the file in another application.
Read the scope alongside the result
CSV fields import as strings. Flattening is not a reversible nested-object mapping, and formula prefixing is not a guarantee for every spreadsheet configuration.