Blank rows become empty objects
Spacer rows in a spreadsheet are still rows. Trim the sheet down to the table before converting for a clean result.
Convert Excel to JSON
Spreadsheets are a comfortable place to author data and an awkward place to consume it. This converter turns a worksheet into a JSON array of objects, using the header row as the keys and preserving the cell types Excel already tracked.
- Runs in your browser
- No signup
- No upload
- Free
ExcelJSON
Runs on your deviceCSV
Options
Reading Excel
Auto-detect reads the first rows and picks the separator that splits them consistently.
Turn off when the file starts straight into data. Columns are then named column_1, column_2, and so on.
Turns "42" into a number and "true" into a boolean. Values with leading zeros stay text so IDs and zip codes survive.
Which worksheet to convert. Filled in once the workbook is read.
Dotted path to the array of records, such as data.items. Leave empty to use the whole document.
Turns {"user":{"id":7}} into a user.id column. Arrays are kept as JSON text.
Pick the encoding the file was written in. Wrong encoding shows up as garbled accents.
Comma-separated words that should become null instead of text.
Writing JSON
Snappy is the default across Spark, DuckDB and pandas. Gzip is smaller but slower to read.
Turns a user.id column back into {"user":{"id":7}}.
Excel needs a byte order mark to open UTF-8 files with accents correctly.
Rows per row group. Larger groups compress better; smaller groups let readers skip more.
Converting…
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Work with Parquet as well?See ParquetReader with ParquetReader — opens Parquet files directly.What happens
How this converter handles Excel to JSON
- Lists the worksheets so you can choose the one to convert.
- Uses the first row as object keys, renaming duplicates rather than dropping columns.
- Preserves types: numeric cells become JSON numbers, dates become ISO-8601 strings, booleans stay booleans.
- Optionally rebuilds nesting, so user.name and user.email columns become a nested user object.
Format differences
Excel vs JSON
Spreadsheet workbooks with sheets, formatting and cell types. Nested, self-describing records that every language can read.
| Excel | JSON | |
|---|---|---|
| Type information | Per cell — text, number, date, boolean | Strings, numbers, booleans, null |
| Structure | Sheets of rows and columns | Nested objects and arrays |
| Compression | Zipped XML | None |
| Typical file size | Smaller than CSV, larger than Parquet | Largest — keys repeat on every record |
| Schema | None beyond the header row | Implicit, per record |
| Human-readable | Only in a spreadsheet app | Yes, though verbose |
| Tool support | Excel, Google Sheets, LibreOffice | Every language, natively |
Worth knowing
What to watch out for
Header names become JSON keys verbatim
A header of "Total (USD)" becomes the key "Total (USD)", spaces and brackets included. Rename headers first if you need clean identifiers.
Only the chosen sheet is converted
The output is one JSON array from one worksheet, not an object keyed by sheet name.
When you need this
Common reasons to convert Excel to JSON
Turning a content spreadsheet into app data
Non-technical teams maintain the sheet; the build step consumes the JSON.
Seeding a database or test fixtures
JSON loads directly into most seeding scripts.
Posting spreadsheet rows to an API
An array of objects is what almost every endpoint expects.
FAQ
Excel to JSON questions
Is my workbook uploaded?
No. The conversion runs in your browser using WebAssembly and JavaScript. The file is read from your disk into a Web Worker, converted in memory, and handed back as a download. It is never sent to a server, so there is nothing for us to store, log or leak.
How are Excel dates represented in the JSON?
As ISO-8601 strings such as 2024-01-31T00:00:00.000Z. JSON has no date type, and ISO-8601 is the format every language can parse without ambiguity.
Can I get nested JSON?
Yes, if the headers encode it. Name columns user.name and user.email, turn on "Rebuild nested objects", and the output nests accordingly.
Is .xls supported?
No — only .xlsx and .xlsm. Re-save legacy files first.
What if the first row is not a header?
Turn off "First row is the header" and the columns are named column_1, column_2 and so on, with every row treated as data.
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