liminfoCSV to JSON
Free web tool: CSV to JSON
About CSV to JSON
The CSV to JSON Converter transforms tabular comma-separated or delimiter-separated data into structured JSON arrays entirely within your browser. Paste raw CSV text or upload a .csv, .tsv, or .txt file, choose your delimiter (comma, tab, semicolon, or pipe), and click Convert to get a prettified JSON array of objects where each header becomes a key. The result can be copied to the clipboard or downloaded as data.json in a single click.
This tool is ideal for frontend developers, data analysts, and API integrators who need to prepare CSV exports from spreadsheets or databases for use in JavaScript applications, REST APIs, or configuration files. Because the entire parsing logic runs in the browser using a hand-rolled RFC 4180-compliant parser that correctly handles quoted fields and escaped double quotes, no data ever touches an external server — making it safe for sensitive business data.
The parser reads the first line as headers and maps every subsequent non-empty row into a key-value object. Fields wrapped in double quotes are unquoted, and escaped double quotes ("") are resolved back to a single quote character. The output is formatted with 2-space indentation via JSON.stringify, giving you clean, readable JSON that is ready to paste directly into code or a JSON validator.
Key Features
- Supports comma, tab, semicolon, and pipe delimiters via a dropdown selector
- RFC 4180-compliant CSV parser handles quoted fields and escaped double quotes correctly
- Upload .csv, .tsv, or .txt files directly — no copy-paste required for large files
- First row is automatically treated as the header row to produce named JSON keys
- Output formatted with 2-space indentation for immediate human readability
- One-click copy to clipboard or download as data.json
- 100% client-side processing — CSV data never leaves your browser
- Empty lines in the input are silently skipped, preventing malformed JSON output
Frequently Asked Questions
What is CSV to JSON conversion?
CSV (Comma-Separated Values) is a flat text format where each row represents a record and columns are separated by a delimiter. JSON (JavaScript Object Notation) is a hierarchical data format used widely in web APIs and configuration. Converting CSV to JSON maps the header row to object keys and each data row to an element in a JSON array, making the data suitable for use in JavaScript, Python, and other programming environments.
How do I convert a CSV file to JSON?
Paste your CSV text into the input area or click "Upload CSV File" to load a .csv, .tsv, or .txt file. Select the correct delimiter (comma is the default), then click "Convert". The JSON output will appear below. Use the Copy button to copy it to your clipboard or Download to save it as data.json.
What delimiters does this tool support?
The tool supports four delimiters: comma (,), tab (\t), semicolon (;), and pipe (|). Select the one matching your file from the Delimiter dropdown before clicking Convert. TSV files exported from spreadsheets typically use the tab delimiter.
Does the parser handle quoted fields with commas inside them?
Yes. The parser is RFC 4180-compliant. Fields enclosed in double quotes are treated as a single value even if they contain commas or newlines. Escaped double quotes ("") within quoted fields are resolved to a single double-quote character in the output.
What is the output JSON format?
The output is a JSON array of objects. Each object corresponds to one data row, and the keys come from the first (header) row. For example, a CSV with columns "name,age,city" produces objects like {"name": "Alice", "age": "30", "city": "Seoul"}. Note that all values are strings; numeric conversion must be done in your own code if needed.
Is there a file size limit?
There is no enforced size limit — the tool processes whatever the browser can hold in memory. In practice, files up to several megabytes convert in milliseconds. Very large files (tens of megabytes) may be slow depending on device RAM, but most real-world CSV exports work without issues.
Is my CSV data secure?
Completely. All parsing runs locally in your browser using JavaScript. No CSV content is sent to any server, logged, or stored. You can safely convert files containing personal data, financial records, or internal business data.
Can I convert TSV (tab-separated) files?
Yes. Select "Tab" from the Delimiter dropdown. You can also upload .tsv files directly via the file picker. The tool treats tab-delimited files identically to CSV files, just with a different separator character.