Paste or upload your CSV
Paste CSV data into the input or upload a file. The first row should contain your column headers.
CSV to JSON Converter
Convert CSV into JSON in your browser: classic string values, or typed JSON (numbers, booleans, null), plus delimiter options, optional snake_case headers and nested objects from dotted column names.
Or upload a CSV or text file
In your browser · Up to 200 MB (50+ MB may feel slow)
Options
Auto picks the most common of comma, tab, semicolon, or pipe in your sample.
Results
Files are processed entirely in your browser and are never uploaded to any server.
HOW IT WORKS
How to convert CSV to JSON
Paste your CSV, convert it to JSON, and download the result instantly. Everything runs in your browser with no uploads or data leaving your device.
Convert CSV to JSON
Choose delimiter (or Auto), Simple vs Typed values, and optional header nesting—then convert. Each row becomes a JSON object keyed by your headers.
Download the JSON file
Download the converted JSON or copy it to your clipboard.
Why use this tool
Why Convert CSV to JSON?
CSV is great for spreadsheets and exports, but many apps, APIs, and scripts expect JSON. Converting CSV to JSON turns your rows into a structured array of objects that JavaScript, databases, and web services can use directly.
Converting CSV to JSON is useful when you need to:
Use data in JavaScript or Node
JSON arrays of objects are native to JavaScript and easy to work with in code.
Send data to APIs
Many REST APIs expect JSON request bodies; converting CSV to JSON prepares your data for upload.
Import into NoSQL databases
Document stores like MongoDB work with JSON documents; CSV to JSON makes imports straightforward.
Build configs or fixtures
Turn spreadsheet exports into JSON for app config, test data, or static site content.
Privacy
Private and Secure Conversion
Your files and pasted data are never uploaded to a server. This CSV to JSON converter runs entirely in your browser using client-side processing.
Data stays on your device
Your data never leaves your browser. No uploads, no cloud storage, no logs.
Nothing stored or sent
No files are stored or transmitted. Conversion happens only in memory.
Fast and private
Conversion is instant and runs locally at full browser speed.
FAQ
Frequently asked questions
Paste or upload your CSV file, and the tool will convert each row into a JSON object using the header row as keys. You can then download or copy the result.
The easiest way is to use a browser-based CSV to JSON converter. It automatically maps rows to objects and columns to properties without requiring Excel or code.
Yes. This tool works entirely in your browser, so you can convert CSV to JSON instantly without using Excel, scripts, or installing software.
Each row in the CSV becomes a JSON object, and each column header becomes a key. The result is typically a JSON array of objects.
The first row is used as property names (keys) in the JSON output. If your CSV does not include headers, the tool may generate default keys.
Yes. Properly formatted CSV files with quoted values and embedded commas are supported and parsed correctly.
If the CSV format is incorrect, the tool may show errors or produce unexpected results. Ensure your file follows standard CSV formatting.
Yes. All processing happens locally in your browser. Your data is never uploaded or sent to a server.
Yes. Under Values, choose Typed: integers, decimals, true/false, the word null, and empty cells become JSON null. Simple mode keeps every cell as a string (the original behavior). List column names under “Keep as string” if a column must stay text (for example IDs with leading zeros).
Pick Comma, Tab, Semicolon, Pipe, or Auto (picks the most common separator in a sample of your text). Custom accepts up to three characters. Quoted fields still follow standard CSV rules.
Enable Nest dotted columns: a header like user.email builds {"user":{"email":…}}. You cannot combine a plain column user with user.something—that is a conflict; rename one column or turn nesting off. Nesting is optional and off by default.