JSON validator
Validate and format JSON, browse its shape, and get the exact line and column of any fault.
/json
Free · no account · nothing uploaded
Data format converter: CSV, JSON, TSV, Base64
Move a table between the formats that different tools insist on, or encode and decode Base64 — and download the result as a real file without uploading the original.
Format converter
Say it the way you would say it to a person. Your words are matched to one of 18 tools by readable rules, and the tool runs right here in your browser. No upload, no account.
This tool runs in your browser and needs JavaScript turned on.
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How to use the format converter
- Drop a CSV, TSV or JSON file into “Your files”, or paste the data into the message box.
- Name the format you want: “convert it to json”, “turn this into a tsv” or “encode it as base64”.
- Check the preview of the converted output in the answer.
- Download the new file from Results. The original is left as it was, and nothing is uploaded.
Things you can type: convert it to json turn this into a tsv
Popular jobs for the format converter
The unglamorous step between every two tools
One system exports CSV. The next expects newline-delimited JSON. A third wants a TSV because a field contains commas. An API hands you a Base64 blob and no hint about what is inside it.
None of this is interesting work, and all of it is work you should not have to paste into an unknown website to get done. This converter runs in the tab.
What it converts
- CSV and TSV to JSON, with headers becoming keys.
- JSON arrays back to CSV or TSV, with consistent column ordering.
- Base64 encoding and decoding for text payloads.
- A download of whatever it produced, named sensibly, generated locally.
Quoting is handled properly
Fields containing the delimiter, embedded newlines and escaped quotes are parsed and re-emitted correctly. That is the whole job of a converter, and it is where the quick ones fail — usually silently, producing a file that opens fine and has shifted every column after the first quoted address.
JSON arrays, or one object per line
Two conventions dominate, and tools rarely say which they want. A JSON array is one document — easy to read whole, awkward to stream, and unusable if the file is larger than memory. Newline-delimited JSON is one object per line: trivial to stream and append, and invalid as a single JSON document.
Log pipelines, bulk-import endpoints and most data warehouses expect the newline-delimited form. Configuration files and APIs expect the array. Converting between them is a two-second job once you know which one is being asked for, and an afternoon of confusing errors when the tool at the other end simply says "invalid JSON".
Why the conversion belongs in your own tab
The files people convert are exports: customer lists, transaction rows, survey responses, API dumps that still contain a key. A free converter that runs on somebody else’s server receives all of it, and its privacy policy is not something you can verify.
Here there is nothing to verify. There is no server to send it to, so nothing is sent.
Questions
Format converter: common questions
Is there a file size limit?
Only your own machine’s memory. There is no server, so there is no quota, no queue and no upload step.
Can it convert a spreadsheet file?
Export it to CSV or TSV first. Binary spreadsheet formats need a parser this page does not carry.
Is Base64 decoding safe here?
The decode happens in your browser and the result stays in the tab, so a payload you would not want to paste into a public website is fine here.