Why convert Excel to JSON
Spreadsheets are where a lot of real-world data starts out, but JSON is what most modern applications, APIs, and JavaScript code actually consume. This tool reads the first sheet of an .xlsx workbook and turns each row into a JSON object, using the header row as the property names, so spreadsheet data becomes immediately usable in a web app, a script, or an API request body.
How the reading process works
Using the SheetJS library running directly in your browser, the tool opens the binary workbook format, locates the first sheet, and converts its cell grid into an array of JavaScript objects, one per data row, automatically inferring numeric and text types from each cell's actual content rather than treating everything as a string the way a raw CSV parse would.
Handling merged cells and blank rows
Merged cells in Excel are represented by their value appearing only in the top-left cell of the merge, and this tool follows that same convention rather than duplicating the value across every cell the merge visually spans. Entirely blank rows are skipped automatically, so you don't end up with empty placeholder objects cluttering the resulting JSON array.
Typical use cases
Developers use this to quickly turn a colleague's Excel export into JSON test data for a web application. Product and data teams use it to convert a manually maintained spreadsheet into a JSON file that can be checked into a codebase or fed directly into an API, without hand-transcribing rows.
A note on formulas and formatting
As with any browser-based Excel reader, formula cells are read as their last calculated value rather than the formula text itself, and visual formatting like colors or bold text has no equivalent in JSON and is not included in the output, only the underlying data values themselves.
Step-by-step walkthrough
Drop your .xlsx or .xls workbook onto the upload area, or click it to browse for the file on your device. The tool reads the first sheet automatically and displays the resulting JSON array in the output box within moments. Click Download Result to save it as converted.json, ready for use in scripts, apps, or API calls.
Privacy and performance
Because the Excel to JSON Converter runs as JavaScript inside your own browser tab rather than on a remote server, there's no upload step, no waiting on a network connection, and no copy of your file sitting on someone else's infrastructure afterward. That also means it keeps working exactly the same whether your file is a few bytes or several megabytes, limited only by your own device's memory rather than a server's queue or rate limit. If you ever want to double-check that nothing is being transmitted, your browser's built-in developer tools network tab will show no outgoing request for the file's contents at any point during conversion. This also means the tool keeps working offline once the page has loaded, and closing the tab afterward leaves no copy behind on any server, since one was never made in the first place. That's a meaningful difference from typical online converters, which usually require uploading your file to a remote service before you ever see a result.
Frequently Asked Questions
Which sheet gets converted if my workbook has several?
The first sheet in the workbook (left-most tab) is converted; reorder your tabs in Excel first if you need a different one.
Are numbers and text correctly typed in the JSON output?
Yes, SheetJS infers each cell's type from its actual content, so numeric cells become JSON numbers rather than quoted strings.
What happens to completely blank rows?
They're skipped automatically so the resulting JSON array doesn't contain empty placeholder objects.
Do formulas convert to their result or their formula text?
Cells export their currently calculated value, the same number or text visible in Excel, not the underlying formula.
Is the workbook uploaded anywhere to convert it?
No, the file is read and converted entirely inside your browser tab.