CSV to JSON Converter
Paste your CSV data below, choose your options, and convert to JSON in one click. Everything runs in your browser — your data never leaves your device.
How to Use This CSV to JSON Converter
Paste or type your CSV data into the input box. Select the delimiter your file uses — comma is the most common, but spreadsheets exported from European locales often use semicolons, and some data pipelines use tabs or pipes. Check First row is headers if your CSV includes a header row; each resulting JSON object will use those header names as keys. Uncheck it if your data has no headers — each row will become a JSON array instead. Click Convert to JSON to see the result, then copy it or download it as a .json file.
What Is CSV?
CSV (Comma-Separated Values) is a plain-text format for tabular data. Each line is a row; fields within a row are separated by a delimiter character (usually a comma). CSV files are the lingua franca of data exchange — virtually every spreadsheet application, database, and analytics tool can export to CSV. Their simplicity makes them easy to generate and parse, but they lack support for nested data, data types, or metadata. JSON fills those gaps.
Why Convert CSV to JSON?
Most modern APIs and web applications work with JSON natively. If you have CSV data you need to feed into a REST API, load into a JavaScript app, store in a document database like MongoDB, or pass to a configuration file, converting it to JSON is usually the first step. JSON also supports nested objects and arrays, which CSV cannot represent — once your data is in JSON, you can restructure and enrich it in ways a flat CSV file doesn't allow.
After converting, you may want to validate or reformat the JSON output. The JSON Formatter can pretty-print, minify, and validate your JSON in one step. If your destination system uses YAML — common for Kubernetes configs, Docker Compose files, or GitHub Actions — the JSON to YAML Converter can take the output from this tool and convert it further.
How the Conversion Works
The converter parses your CSV row by row. When First row is headers is enabled, the first row becomes the list of property names and every subsequent row becomes a JSON object like {"name":"Alice","age":"30"}. When headers are disabled, each row becomes a simple JSON array like ["Alice","30"], and the result is an array of arrays.
All values are treated as strings unless a value is empty — empty fields become null. If you need type coercion (converting "30" to the number 30), edit the JSON output after conversion or use a script to post-process it.
Handling Quoted Fields and Special Characters
CSV fields that contain the delimiter character or a newline are enclosed in double quotes in standard CSV files (per RFC 4180). For example: "Smith, John" is a single field containing a comma. This converter handles double-quoted fields correctly, including escaped quotes inside a field written as "". Bare quotes (a quote not at the start of a field) are treated as literal characters.
Frequently Asked Questions
What happens to empty cells?
Empty cells — two delimiters with nothing between them, or a trailing delimiter at the end of a line — become null in the JSON output. This preserves the structure of your data and makes missing values explicit and easy to detect in code.
Can I convert a tab-delimited file (TSV)?
Yes. Select Tab from the delimiter dropdown and paste your TSV data. Tab-separated files exported from Excel or Google Sheets work exactly the same way as comma-separated files — only the separator character changes.
Does this tool handle large CSV files?
Because the conversion runs entirely in your browser using JavaScript, performance depends on your device. Files with up to tens of thousands of rows convert in under a second on any modern computer or phone. For files with hundreds of thousands of rows, a server-side tool or a command-line utility like csvtojson (Node.js) or Python's built-in csv module will be faster.
Are my numbers and booleans converted to the right JSON types?
This converter keeps all values as JSON strings to avoid making incorrect assumptions about your data types. A CSV value of true stays "true" (a string), and 42 stays "42". This is the safest default — you can always post-process the JSON to coerce types as needed using JSON.parse with a reviver function, or a tool like jq.
What if my CSV has duplicate header names?
If two columns share the same header name, only the value from the last column with that name is kept in each JSON object — earlier duplicate keys are overwritten. To avoid data loss, make sure your header row has unique column names before converting.
Is my data private?
Yes. All conversion happens locally in your browser. No data is sent to any server. This makes the tool safe to use with database exports, internal reports, API keys embedded in config data, or any other sensitive information.
