Excel to JSON Converter

Q: What spreadsheet file formats are supported?

The tool supports standard Microsoft Excel formats (.xlsx and .xls), along with common comma-separated text sheets (.csv).

Convert Excel spreadsheets (.xlsx, .xls, .csv) to structured JSON array data instantly. Choose worksheets locally and validate formatting.

Learn About This Tool

Understanding Excel to JSON conversion rules

Microsoft Excel stores data inside rows and columns across separate worksheets. Web applications and databases expect JSON structures (an array of key-value objects) to parse configurations. When converting Excel worksheets to JSON arrays, the first row is treated as key headers, and every subsequent row forms a JSON object mapped to those keys. If you need to export JSON database records back to visual Excel spreadsheets, use our JSON to Excel Converter. Here is a visual representation of how table rows map to objects:

# Excel Spreadsheet Table
| UserID | Username | Active |
| 101    | Avery    | TRUE   |
| 102    | Casey    | FALSE  |

// Converted JSON Array Output
[
  {
    "UserID": 101,
    "Username": "Avery",
    "Active": true
  },
  {
    "UserID": 102,
    "Username": "Casey",
    "Active": false
  }
]

Maps sheet column headers (first row) to standard JSON object properties
Translates list rows into individual indexed JSON objects
Casts numeric digits and boolean states (TRUE/FALSE) into native JSON types
Executes completely in browser memory, protecting corporate lists and salaries

Support for multi-sheet workbooks and worksheet selections

Excel files can bundle multiple sheets (e.g. Sales, Employees, Inventory) in a single workbook. Our client-side parser reads the binary workbook and dynamically populates a sheet selector dropdown. This lets you toggle between sheets and convert them one-by-one. If you need to convert plain comma-separated variables without uploading files, try our CSV to JSON Converter.

Reads binary workbook sheets locally using HTML5 FileReader array buffers
Displays interactive worksheets select dropdown controls in header toolbar
Strips out empty cells and blank padding lines automatically
Maintains columns key values alignment across large datasets

Why security-first client-side parsing matters

Spreadsheets commonly contain database exports, payroll details, customer emails, and private transaction records. Using cloud converters that process files server-side exposes this confidential data to leaks or caching risks. Our browser-native parser runs entirely in browser memory. Your spreadsheets are never uploaded to any remote server. If you are formatting JSON files before sending them to APIs or servers, pretty print them using our JSON Formatter & Validator.

Ensures that no spreadsheet rows ever leave your machine's physical memory
Zero network packets are transmitted to external servers during conversion
Protects enterprise and database records from potential database leaks
Processes worksheets instantly without file size transfer delays

How to Use Excel to JSON Converter

Upload or drag-and-drop your spreadsheet

Select a spreadsheet file (.xlsx, .xls, or .csv) or drag it into the file upload container. The browser reads the metadata instantly.

Select your target worksheet

If your Excel file contains multiple worksheets, use the sheet selector dropdown in the header toolbar to choose which sheet to convert.

Copy or download the formatted JSON

The output panel displays the parsed JSON string. Click Copy to grab it or Download to save it locally as a .json file.

Common questions

How do I convert Excel to JSON online?

Simply drop your spreadsheet file into the input panel of our secure, client-side Excel to JSON tool. The parser translates the syntax in real-time, allowing you to download the output as a .json file. If you need to convert JSON data back to Excel sheets, use our JSON to Excel Converter.

Is this Excel to JSON converter secure for confidential spreadsheets?

Yes, 100%. The conversion runs completely in your local browser sandbox using client-side JavaScript. No data is sent to external servers, protecting your company records, salaries, and email lists.

Can I choose which sheet to convert in multi-sheet files?

Yes. When you upload a workbook containing multiple sheets, the tool automatically detects them and displays an interactive dropdown to select the target sheet.

What spreadsheet file formats are supported?

The tool supports standard Microsoft Excel formats (.xlsx and .xls), along with common comma-separated text sheets (.csv).

How does the converter handle empty cells?

Empty cells are omitted from the resulting JSON objects to keep the payload size minimal. You can also configure default cell mapping inside your workflows.

Does it convert formulas or the evaluated values?

The converter extracts and outputs the **calculated values** of the formulas (e.g. if a cell contains =SUM(A1:A3), it outputs the sum value like 60), not the formula text.

How are date cells parsed in the JSON output?

Excel dates are converted into standard ISO date string format (e.g. 2026-07-07T12:00:00.000Z) or numeric serial numbers depending on formatting.

What is the maximum file size limit for sheet conversions?

Since parsing occurs locally in your browser, it is only limited by your device's memory. Spreadsheets exceeding 50,000 rows are converted instantly.

Are row indices preserved in the JSON output?

No, the output is formatted as a standard JSON array of objects where index offsets start from 0, omitting empty headers or design padding cells.

Can I copy the output JSON instantly?

Yes. Click the Copy button in the JSON Output header, or use standard browser shortcuts to copy the compiled text instantly to your clipboard.

Does it format the JSON output string?

Yes, the output is formatted as pretty-printed JSON with a 2-space indentation by default, making it highly readable and ready for Git diff comparisons.

What library does this tool use to parse Excel files?

The tool uses the industry standard xlsx (SheetJS) npm library, ensuring strict compliance with standard spreadsheet formats.

Can I load an example file to test?

Yes, if you don't have an Excel file on hand, you can click 'Example' to instantly simulate a parsed 3-row user database list to test formatting features.

How does the tool handle formatting styles or cell colors?

Since JSON is a data-only format, all cell colors, font weights, borders, and visual formatting styles are discarded, extracting only the raw values.

Why did my conversion fail with 'Invalid workbook'?

This error occurs if the file is corrupted, encrypted with a password, or has an unsupported layout extension that SheetJS cannot parse.