Convert XLS to JSON Online Free

Transform legacy Excel .xls spreadsheets into structured JSON arrays. Each row becomes a JSON object with column headers as property names. No Microsoft Office required.

By ChangeThisFile Team · Last updated: March 2026

Quick Answer

To convert XLS to JSON, drop your legacy Excel file onto the ChangeThisFile converter. Column headers become JSON keys and each row becomes an object in a JSON array. Free, browser-based, no Excel installation needed, and your data is never uploaded.

Free No signup required Files stay on your device Instant conversion Updated March 2026

Convert XLS to JSON

Drop your XLS file here to convert it instantly

Drag & drop your .xls file here, or click to browse

Convert to JSON instantly

XLS vs JSON: Format Comparison

Key differences between the two formats

Feature	XLS (Excel Legacy)	JSON
File format	Binary BIFF format (pre-2007)	Plain text, human-readable
Structure	Flat rows and columns with sheets	Nested objects and arrays
Data types	Numbers, text, dates, booleans, formulas	Strings, numbers, booleans, null, nested objects
Max rows	65,536 rows per sheet	No limit
Formatting	Fonts, colors, borders	None (data only)
API compatibility	Not directly usable in APIs	The standard format for REST APIs
Programmatic use	Requires Excel or parser library	Native in JavaScript, Python, and most languages

When to Convert

Common scenarios where this conversion is useful

Migrating legacy data for web applications

Convert archived XLS files into JSON for use in modern web applications, APIs, and JavaScript-based data processing.

Importing old spreadsheets into NoSQL databases

MongoDB, Firestore, and CouchDB accept JSON documents. Convert legacy XLS data directly into JSON for database imports.

Building API payloads from old reports

Transform legacy Excel reports into JSON arrays for bulk POST requests to REST APIs or webhook integrations.

Data recovery from legacy formats

Extract data from old .xls files without needing legacy Excel installations. Convert to JSON for universal access in modern tools.

Who Uses This Conversion

Tailored guidance for different workflows

Office Workers

Convert XLS documents to JSON for sharing with colleagues who use different software
Transform XLS reports to JSON for archiving or distribution to external stakeholders

Review the converted JSON for formatting changes, especially tables, headers, and page breaks

Convert to JSON as the final step after all edits are complete to avoid formatting drift

Students

Convert XLS lecture notes to JSON for submitting assignments in the required format
Transform XLS study materials to JSON for reading on tablets or e-readers

Double-check that fonts and special characters render correctly in the converted JSON file

Save a backup of your XLS original before converting, in case you need to make edits later

Professionals

Convert XLS contracts or proposals to JSON for secure, read-only distribution to clients
Transform XLS templates to JSON for use across different office suites and platforms

Verify that hyperlinks and cross-references still work after converting XLS to JSON

For legally sensitive documents, confirm the JSON output matches the XLS layout exactly

How to Convert XLS to JSON

1

Upload your XLS file

Drag and drop your .xls file onto the converter, or click to browse. Excel 97-2003 binary format is fully supported.
2

Automatic conversion

The first row becomes JSON property names. Each subsequent row becomes a JSON object. Formulas are resolved to their computed values.
3

Download the JSON result

Click Download to save your .json file. The output is pretty-printed with 2-space indentation.

Frequently Asked Questions

What XLS versions are supported?

The converter supports Excel 97-2003 .xls files (BIFF8 format). This covers all .xls files created by Excel 97, 2000, XP, and 2003.

Which sheet is converted?

The first (leftmost) sheet in the workbook is converted to JSON. Rearrange sheets before converting if you need a different one.

Are formulas resolved?

Yes. Formulas are resolved to their last computed values. The JSON output contains calculated results, not formula expressions.

Are numbers preserved as JSON numbers?

Yes. Excel numbers become JSON numbers. Integer values become integers, and decimal values become floats in the JSON output.

How are dates handled?

Excel dates are converted to their formatted text representation based on the cell's date format.

What about merged cells?

Merged cells are unmerged. The value appears in the property for the top-left cell, and other cells in the merge range become empty or null.

Do I need Excel installed?

No. The converter uses SheetJS to parse XLS files entirely in your browser. No Microsoft Office installation is needed.

Is the JSON output formatted?

Yes. The output is pretty-printed with 2-space indentation for readability. Each object in the array is clearly structured.

Can I convert password-protected files?

No. Password-protected XLS files cannot be read by the browser-based parser. Remove the password protection first.

Is my data secure?

Yes. The conversion happens entirely in your browser. Your legacy spreadsheet data is never sent to any server.

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Need to convert programmatically?

Use the ChangeThisFile API to convert XLS to JSON in your app. No rate limits, up to 500MB files, simple REST endpoint.

View API Docs

Read our guides on file formats and conversion

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