Convert CSV files to JSON with customizable parsing options
Drag & drop files here
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Accepted: .csv,text/csv
Large file performance?
Browser local processing works best on Desktop for files over 100MB.
CSV parsing presents challenges: delimiter ambiguity (commas vs semicolons vs tabs), quoted field handling where commas appear within values, escape character processing, header row detection, multi-line field support. This parser addresses these through configurable options—specify delimiter type, toggle header interpretation, handle RFC 4180 compliance. Reads CSV line-by-line, constructs JavaScript objects mapping column headers to values, serializes to JSON array. Edge cases like embedded newlines within quoted fields require proper state machine parsing. Execution happens in browser memory—customer databases, financial spreadsheets, proprietary datasets never upload to servers. Useful when API endpoints expect JSON but you maintain data in Excel, or when migrating from relational databases to NoSQL document stores.
Learn more about this tool and related topics in our blog.
Practical guide to converting between JSON, CSV, XML, and YAML. Plus how to format messy JSON that makes your eyes bleed.
Privacy isn't a perk, it's a requirement. See why top developers are ditching cloud converters for local-first browser utilities.
Stop uploading sensitive spreadsheets to the cloud. Learn how to convert CSV to JSON safely in your browser while preserving data privacy.
This tool uses client-side WebAssembly to ensure your data never touches a server. Secure, fast, and 100% private by design.
Paste your CSV data into the input box or upload a file.
The tool will automatically parse the data.
Adjust settings if needed (e.g., 'First row is header').
View the JSON result in the output box.
Click 'Download JSON' or 'Copy' to save your data.
Convert employee data from CSV to JSON format
name,age,city John Doe,30,New York Jane Smith,25,Los Angeles Bob Johnson,35,Chicago
[
{"name": "John Doe", "age": "30", "city": "New York"},
{"name": "Jane Smith", "age": "25", "city": "Los Angeles"},
{"name": "Bob Johnson", "age": "35", "city": "Chicago"}
]Handle European-style CSV with semicolons
product;price;stock Laptop;999.99;15 Mouse;29.99;50
[
{"product": "Laptop", "price": "999.99", "stock": "15"},
{"product": "Mouse", "price": "29.99", "stock": "50"}
]Convert data-only CSV to array of arrays
Alice,Developer,2020 Bob,Designer,2021 Carol,Manager,2019
[ ["Alice", "Developer", "2020"], ["Bob", "Designer", "2021"], ["Carol", "Manager", "2019"] ]
Convert spreadsheet data to JSON for REST API consumption.
Import SQL table data into MongoDB or Firebase.
Transform spreadsheet configs into JSON for applications.
Convert Excel reports to JSON for JavaScript analysis.
CSV (Comma-Separated Values) is a simple format where: - **Delimiter**: Character separating values (comma, semicolon, tab) - **Quoted Fields**: Fields containing delimiter must be wrapped in double quotes - **Escape Quotes**: Quotes within quoted fields are escaped by doubling: \"\" Standard: RFC 4180 defines CSV format, but many variations exist. Our parser is lenient and handles most formats.
CSV files are plain text with no type information: - **All values are strings**: \"123\" is text, not a number - **No boolean type**: \"true\" and \"false\" are strings - **No null/undefined**: Empty cells become empty strings - **Dates**: Stored as text (\"2024-01-15\"), not Date objects JSON output preserves this string nature. Type conversion must happen in your application.
Processing happens entirely in browser memory: - **Small files (< 1MB)**: Instant conversion - **Medium files (1-10MB)**: 1-2 seconds - **Large files (10-100MB)**: 3-10 seconds - **Very large (> 100MB)**: May slow browser, consider splitting A 10,000-row CSV uses ~5MB browser RAM. 100,000 rows uses ~50MB.
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Learn more about this tool and related topics in our blog.
Practical guide to converting between JSON, CSV, XML, and YAML. Plus how to format messy JSON that makes your eyes bleed.
Privacy isn't a perk, it's a requirement. See why top developers are ditching cloud converters for local-first browser utilities.
Stop uploading sensitive spreadsheets to the cloud. Learn how to convert CSV to JSON safely in your browser while preserving data privacy.