CSV to JSON Converter
Paste CSV data and get formatted JSON instantly. Auto-detects delimiters, supports headers. Free, no signup.
What Is CSV?
CSV (Comma-Separated Values) is a plain-text file format that stores tabular data in rows and columns. Each line represents a row, and fields within a row are separated by a delimiter -- most commonly a comma, but semicolons and tabs are also used. CSV files are supported by virtually every spreadsheet application, database tool, and programming language.
CSV is popular because it is simple, human-readable, and universally compatible. However, it lacks support for nested data, data types, and metadata -- which is where JSON excels.
CSV vs JSON: What Is the Difference?
| Feature | CSV | JSON |
|---|---|---|
| Structure | Flat, tabular (rows and columns) | Hierarchical, nested objects and arrays |
| Data types | Everything is a string | Strings, numbers, booleans, nulls, arrays, objects |
| Readability | Easy for small datasets | Easy with pretty-printing |
| File size | Smaller (less overhead) | Larger (keys repeated per object) |
| Nesting | Not supported | Fully supported |
| API usage | Rarely used in APIs | The standard for REST and web APIs |
| Spreadsheet support | Native (Excel, Google Sheets) | Requires import/conversion |
How to Convert CSV to JSON
Converting CSV to JSON follows a simple process:
- Parse the header row -- the first row typically contains column names that become JSON keys.
- Detect the delimiter -- identify whether fields are separated by commas, semicolons, or tabs.
- Parse each data row -- split each subsequent row by the delimiter, handling quoted fields correctly.
- Map to JSON objects -- pair each field with its corresponding header to create key-value pairs.
- Output as JSON array -- wrap all objects in a JSON array and format with indentation.
Our tool above handles all of these steps automatically, including edge cases like quoted fields with embedded commas and multi-line values.
When to Use CSV vs JSON
Use CSV when working with flat, tabular data that will be opened in spreadsheets or imported into databases. Use JSON when building web applications, working with APIs, or when your data has nested relationships. Converting from CSV to JSON is common when migrating data from spreadsheets to web applications or preparing data for API consumption.
Frequently Asked Questions
Is this CSV to JSON converter free?
Yes, completely free with no signup required. Your data is processed entirely in your browser and never sent to any server.
What delimiters does this tool support?
The tool auto-detects commas, semicolons, and tabs. You can also manually override the delimiter using the dropdown.
Can I convert CSV without headers?
Yes. Uncheck the "First row as headers" option and the tool will output a JSON array of arrays instead of an array of objects.
Does this tool handle quoted CSV fields?
Yes. Fields wrapped in double quotes are parsed correctly, including fields that contain the delimiter character or escaped quotes ("").
What is the maximum CSV size I can convert?
Since processing happens in your browser, there is no server-side limit. Performance depends on your device, but most files up to several megabytes convert instantly.
Is my data safe?
Absolutely. All conversion happens client-side in your browser. No data is uploaded, stored, or transmitted to any server.