Free · No signup · Browser-based

Convert Excel to JSON.

Drop an Excel spreadsheet and get a typed JSON array of objects — numbers stay numbers, booleans stay booleans, empty cells become null. It all runs in your browser — no signup, no upload, no watermark.

To convert Excel to JSON, drop or paste an Excel spreadsheet — csvtodashboard parses it into rows and columns in your browser, then emits a typed JSON array of objects. Numbers, booleans and blank cells become real JSON numbers, booleans and null — not quoted strings — though dates stay as ISO text since JSON has no date type. Nothing is uploaded; the whole conversion runs on your device.

01 · How it works

Three steps, then done.

This converter reads the first sheet of your .xlsx or .xls workbook (pick another sheet if it has several); the top row becomes the field names and every row below becomes a record, then writes a typed JSON array of objects — numbers stay numbers, booleans stay booleans, empty cells become null. Both sides are tabular, so it is a clean, lossless mapping — no nesting to flatten and no structure to guess. Types are inferred as the data is read, and the whole conversion runs locally in your browser, so your file never leaves your device.

i. drop

Drop or paste

Drag a file, click to choose, or paste data directly into the input pane.

ii. detect

We read the shape

Types are inferred so the output is correctly formatted — not strings everywhere.

iii. use it

Copy, download, or dashboard

Copy the output, download it, or hit 'Build dashboard' to chart what's in the data.

02 · Why ours

Smart JSON conversion by default.

Free JSON converters often produce sloppy output — every value quoted, types lost, errors swallowed. Ours infers types where it can, fails loudly when it can't, and pairs the conversion with a one-click path to a dashboard.

  • 01

    Correct types

    Numbers, booleans and nulls are preserved wherever JSON supports them — not every value dumped as a quoted string.

  • 02

    Local-first

    Your file is parsed and converted in your browser — verify in DevTools → Network. Nothing is uploaded, logged, or stored.

  • 03

    Fails loudly

    Malformed input gives a clear, specific error instead of silently wrong output — so you can trust what comes back.

  • 04

    One click to a dashboard

    Every conversion keeps a tabular copy, so you can send the data straight to our visualization tool to chart it.

"Needed a conversion. Ended up with a dashboard. That's the pattern."
— the typical csvtodashboard arc
Good to know

excel to json notes.

Format-specific details worth knowing before you convert Excel to JSON.

  • Types are inferred, not quoted

    Numeric columns become JSON numbers, true/false become booleans, and empty cells become null, so downstream code gets a real typed array of objects rather than strings everywhere.

  • No native date type

    JSON has no date type, so dates are kept as ISO-8601 strings like "2026-01-31" instead of being guessed — lossless, but your code does the parsing.

  • Precision beyond 2^53

    JSON numbers are IEEE-754 doubles, so very long integers such as 19-digit IDs lose precision. Keep those columns as text if exactness matters.

03 · FAQ

excel to json questions.

What Excel input works?
Any .xlsx or .xls workbook. The first sheet is used by default; multi-sheet files show a picker so you choose which one. The top row is treated as the header.
Yes. Numeric columns become JSON numbers, true/false become booleans, and blanks become null — a real typed array of objects, not strings everywhere.
No hard limit. Parsing and conversion run in your browser, with large inputs handled off the main thread so the tab stays responsive — you are bounded only by your device's memory.
No. The entire excel-to-json conversion happens locally in your browser — the file never touches a server. Watch DevTools → Network to confirm nothing is sent.
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