Is my data sent to a server?

No. CSV ↔ JSON Converter runs entirely in your browser — the parser is JavaScript and your data never leaves the tab. That holds in both directions, which is why it keeps working offline once the page has loaded.

What happens if my CSV is malformed?

You get the exact line and column of the first problem — an unterminated quote, a stray quote in the middle of a field, or a row with a different number of columns than the rest — not just a red cross. Rows with the wrong number of fields are rejected rather than silently padded or truncated.

Does this guess the type of a CSV value?

No, and deliberately so. Every CSV value becomes a JSON string — "42" stays "42", "true" stays "true" — because guessing a number, boolean or null from plain text is exactly the kind of silent wrong answer this toolkit avoids elsewhere (see Timestamp Converter's own FAQ on ambiguous dates). Convert the result's types yourself if you need them.

What does JSON → CSV require of my JSON?

A JSON array of flat objects — [{"name":"Ada"}, {"name":"Grace"}]. A value that is itself an object or array is rejected with the record and field named, rather than being flattened automatically: how to flatten a nested structure into columns is a real design decision, and this tool won't make it silently on your behalf.

What if my JSON objects don't all have the same keys?

The CSV gets one column for every key seen anywhere in the array, in the order each first appears. A record missing a given key gets an empty cell in that column rather than being rejected.

Which delimiters are supported?

Comma, semicolon and tab — chosen per run, and used in both directions, since JSON → CSV has to write the same character CSV → JSON reads. A field containing the chosen delimiter, a quote, or a line break is automatically quoted in the output, per the standard CSV quoting rule (RFC 4180).

Conversion toolkitFreeFastPopular

CSV ↔ JSON Converter

Convert a CSV export into an array of JSON objects, or a JSON array back into CSV — with the exact row and column of any malformed data, entirely in your browser.

instantaverage
In-browserprocessing
Zerouploads
Runs in your browser
Nothing is uploaded
No signup required

Conversion toolkit

CSV ↔ JSON Converter

Delimiter

First row is a header

JSON indent

Input

Output

The converted result appears here as you type.

Ln 1, Col 1

Waiting for input

Paste, upload or type to begin.

Shortcuts⇧⌘CCopy output⌘LClear input

People also use

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Why Kalyvor

Built for people who value their time

Every converters tool is fast, private and genuinely free — no dark patterns, no surprises.

Fast cloud processing

Jobs run on dedicated workers and finish in seconds — no queue, no spinner you can go make coffee to.

Auto file deletion

Everything you upload is erased the moment the job finishes. Nothing is written to long-term storage, so there is no retention period to wait out.

Works everywhere

Desktop, tablet or phone, any modern browser. Nothing to install, no plugins, no extensions.

Batch processing

Drop in a folder's worth of files and run the whole set through one tool in a single pass.

Privacy first

Encrypted in transit, never used to train models, never sold. Many tools never send the file at all.

No installation

Open a tab and go. No account needed to start, no download, no licence key to hunt for.

How it works

CSV ↔ JSON Converter in three steps

No account, no installation, no manual. It takes about as long to do as it does to read.

01
Paste your CSV or JSON
Paste a spreadsheet export or a JSON array directly — the direction picks which one is expected. Nothing is uploaded.
02
Pick a direction
CSV → JSON reads a header row (optional) and a delimiter; JSON → CSV expects a flat array of objects.
03
Copy or download
The result is ready the moment you stop typing — usually instantly.

Questions

Frequently asked questions

Everything worth knowing before you run your first CSV ↔ JSON Converter job. Still stuck? Talk to support.

Helpful articles

Guides and walkthroughs for getting more out of CSV ↔ JSON Converter.

How Kalyvor keeps your files private

Encryption in transit, immediate deletion and what browser-side processing actually means.

4 min read

Batch processing: run 100 files at once

A practical walkthrough of queueing large jobs without babysitting the tab.

6 min read

Choosing the right tool for the job

A short decision guide for when two tools look like they do the same thing.

5 min read

Getting started with Kalyvor

From first upload to finished download in under a minute — the whole flow.

3 min read

Secure by default

files auto-deleted

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CSV ↔ JSON Converter

CSV ↔ JSON Converter

People also use

JSON Formatter

XML Formatter

Timestamp Converter

Built for people who value their time

Fast cloud processing

Auto file deletion

Works everywhere

Batch processing

Privacy first

No installation

CSV ↔ JSON Converter in three steps

Paste your CSV or JSON

Pick a direction

Copy or download

Frequently asked questions

Helpful articles

How Kalyvor keeps your files private

Batch processing: run 100 files at once

Choosing the right tool for the job

Getting started with Kalyvor

Explore more Developer tools