JSON to CSV / CSV to JSON Converter – Free & Private
Convert between JSON and CSV formats instantly in your browser. No uploads, no tracking, no servers — your data stays on your device.
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Why Use Tools Oasis JSON / CSV Converter?
Working with data often means switching between JSON and CSV. Many online converters upload your data to remote servers, risking your privacy. Tools Oasis runs entirely in your browser — your data never leaves your device.
Processing latency
Client-side conversion is instant. Paste JSON and get CSV in milliseconds — no server needed.
In-Browser Processing
All logic runs in JavaScript locally — zero server calls, zero latency from network round-trips.
Secure by Default
No logging, no telemetry, no account needed. Your code and data stay yours.
Works Offline
Once the page has loaded, every tool works without an internet connection.
Frequently Asked Questions
01 What formats are supported?
This tool converts between JSON (arrays of objects) and CSV (comma-separated values). It supports standard JSON arrays where each element is an object with key-value pairs, and standard CSV files with a header row followed by data rows.
02 Does it handle nested JSON?
Nested objects and arrays within your JSON are automatically flattened using dot notation. For example, a field like {"address":{"city":"Paris"}} becomes the CSV column address.city with the value Paris. This keeps your CSV clean and readable.
03 What delimiter options are available?
You can choose from four delimiters: comma (the default), semicolon (common in European locales), tab (for TSV files), and pipe. Select your preferred delimiter before converting in either direction.
04 Is there a maximum data size?
There is no hard limit. Since all processing happens in your browser, performance depends on your device. Most modern browsers handle files with tens of thousands of rows without issues. For extremely large datasets (over 50 MB), you may experience slower performance.
05 Is this converter private and free?
Yes. Tools Oasis JSON/CSV Converter is 100% free with no signup required. All conversion happens locally in your browser using JavaScript — no data is uploaded, no data is stored, and no third parties have access to your content.