CSV & XLSX to JSON Converter
Convert CSV, TSV, and Excel (XLSX, XLS) spreadsheets to clean JSON with live real-time preview and multi-sheet support.
🔒 100% Client-Side Processing • Your files and data never leave this device.
Click to select a file or drag & drop here
Supports CSV, TSV, and Excel (.xlsx, .xls)
100% Client-Side In-Browser • Files are never sent over the internet
Drop another file to replace
or click to browse from device
Generated JSON will appear here
Upload a CSV or Excel file, paste spreadsheet text, or click "Try Sample" above.
How to Convert CSV & Excel (XLSX) to JSON
Transform your datasets, spreadsheets, and inventory catalogs into valid, formatted JSON in four simple steps.
Upload or Paste
Drag & drop your .csv, .xlsx, or .xls file into the upload zone, or switch to Paste Text to paste raw spreadsheet contents.
Select Sheet & Format
For Excel files, pick a specific workbook tab or export all sheets. Select your desired output structure (Array of Objects, 2D Array, or Keyed).
Live Preview & Inspect
Switch between the formatted JSON code view and the interactive Table Preview to verify your columns, row counts, and data types.
Copy or Download
Copy the generated JSON payload to your clipboard with one click, or save it to your computer as a formatted .json file.
Private, Instant Spreadsheet Conversion in Your Browser
Developers, analysts, and e-commerce sellers frequently need to import Excel reports, inventory CSVs, or customer rosters into web applications, REST APIs, or databases like MongoDB and PostgreSQL.
Traditional online converters upload your confidential spreadsheets to third-party cloud servers, risking your business data, customer addresses, and financial numbers.
ToolLab's CSV & XLSX to JSON Converter runs 100% locally in your web browser using modern JavaScript and WebAssembly. Your files are parsed in memory with zero cloud transmission, zero server delays, and total privacy.
Key Capabilities
-
Multi-Format Support: Accepts comma-separated (.csv), tab-separated (.tsv), and native Excel workbooks (.xlsx and .xls).
-
Excel Multi-Sheet Navigation: Easily switch between different worksheet tabs or export all sheets simultaneously into a combined JSON object.
-
Four JSON Output Structures: Export as Array of Objects, 2D Arrays, Keyed Dictionaries (by Column), or Column-based Arrays.
-
Interactive Table & Code Views: Preview your rows and columns in a formatted responsive table alongside the syntax-styled JSON editor.
-
Smart Type Casting: Automatically parses numbers, booleans, and null values into native JSON data types.
Frequently Asked Questions
No, never. All parsing, file reading, and JSON conversion occur 100% client-side inside your browser via local JavaScript. No files, row records, or credentials ever leave your computer.
Yes! When you upload an .xlsx or .xls file with multiple tabs, the tool automatically detects all sheets and allows you to select an individual sheet or convert all sheets together into a combined JSON object.
You can export your data as an Array of Objects (standard row records), a 2D Array (array of arrays including header row), Keyed Object (indexed by a specific column such as ID), or Column-Oriented Arrays.
Yes, switch to the "Paste Text" tab to type or paste raw CSV, TSV, or custom delimited data with instant real-time live preview.
Yes, when the "Parse Numbers & Booleans" option is enabled, numeric values like 4999 and booleans like true/false are automatically converted into native JSON types rather than strings.
Yes, switch between the "JSON Output" tab and the interactive "Table Preview" tab to inspect your parsed rows, columns, and data types directly in the workspace.