How it Works

JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy to read and write for humans and machines. CSV (Comma-Separated Values) is a common storage format for spreadsheets and databases. This tool uses a JavaScript library (PapaParse) to parse and convert data directly in your browser without uploading to a server, ensuring speed and privacy.

Usage Scenarios

Excel Data Processing: Programmers often need to convert CSV data from Excel into JSON for APIs, or convert JSON API responses into CSV for viewing in Excel.
Database Migration: Many databases (like MySQL, MongoDB) support importing/exporting CSV or JSON formats. This tool acts as a bridge for format conversion.

FAQ

Are nested JSON objects supported?

Yes. The tool attempts to "flatten" nested objects. For example, `user: { name: "John" }` converts to a header `user.name` with value `John`. This is standard for handling complex structures.

Is there a file size limit?

Since all conversion happens locally in your browser, the limit depends on your device's RAM. Generally, text files up to tens of MBs are fine, but very large files (e.g., 500MB+) might slow down the browser.

Is my data uploaded?

Absolutely not. This is a client-side only tool. Your data never leaves your device and works even when offline.

What is the default CSV delimiter?

The default delimiter is a comma (`,`), which is the standard. If field content includes commas, the tool automatically wraps it in double quotes.

Are JSON arrays and single objects supported?

Yes. If it's a JSON array `[{...}, {...}]`, each object is a row. If it's a single JSON object `{...}`, there will be only one row of data.

Can I convert MySQL export files?

Yes. If your MySQL export is CSV, paste it on the right to convert to JSON. If it's JSON, paste it on the left to convert to CSV for Excel.

What about character encoding?

The tool uses UTF-8 encoding entirely. If Excel shows garbled characters, use the "Data" -> "From Text/CSV" feature in Excel and select UTF-8 as the file origin.

Is one-click copy supported?

Yes. Each editor has a "Copy" button below it to instantly copy the current content to your clipboard.

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JSON <-> CSV / Excel Converter