CSV → JSON Converter
Paste CSV data and instantly get JSON (or NDJSON). Everything runs offline in your browser — your data never leaves the device.
All conversion happens locally in your browser. No data is uploaded or stored.
The PulseTools CSV → JSON Converter turns a comma‑separated values file into a JSON array (or NDJSON stream) directly in your browser. You paste or drag‑drop a CSV file, choose a delimiter if it isn’t a comma, and the tool parses the rows, infers basic data types, and shows a formatted preview. Because all processing happens locally, nothing is uploaded to a server and the conversion works even when you are offline.
Use this converter when you need quick JSON for a script, an API payload, or a data‑pipeline step and you don’t want to install a separate program. It does not perform deep data cleaning, complex schema mapping, or large‑file streaming – files larger than a few megabytes may slow the browser. You can copy the result, download it as a .json or .ndjson file, or continue editing the CSV before converting again.
How to Use CSV → JSON Converter
- Upload or paste your CSV — Click the file area or drag a CSV file, or paste the text into the input box.
- Set delimiter and options — If your file uses semicolons, tabs, or another character, select it; you can also toggle type inference.
- Preview the JSON — The right pane shows the generated JSON with syntax highlighting; verify that the structure matches your expectations.
- Download or copy — Press the Download button to save as .json or .ndjson, or click Copy to place the result on the clipboard.
Frequently Asked Questions
Can I convert large CSV files with this tool?
The converter works best with files up to a few megabytes. Larger files may cause the browser to become slow or unresponsive because all parsing happens in memory without server assistance.
Is my data sent to any server during conversion?
No. All processing occurs locally in your browser, so nothing is uploaded or stored remotely. Your data stays on your device, even when you are offline.
What is the difference between JSON and NDJSON output?
JSON produces a single array or object that contains the whole dataset, while NDJSON (newline‑delimited JSON) writes each record as an independent JSON object on its own line, which is useful for streaming or line‑by‑line processing.
Can I customize the data types that are inferred?
The tool automatically infers numbers, booleans, and dates based on simple patterns. It does not allow custom type mappings; for advanced type control you would need a separate script after conversion.
Does the converter work on mobile browsers?
Yes, the interface is responsive and runs in any modern mobile browser. The same privacy guarantees apply: conversion happens entirely on the device without any network traffic.