Excel data converter
Read an xlsx file into a JSON object array or CSV text, with optional sheet selection and header handling. Parsing runs in Rust-compiled WebAssembly, so the workbook never leaves your browser.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
xlsx base64
Parsed result
JSON is an object array; CSV uses CRLF line breaks and commas.
Loading the parser module…
Paste the xlsx base64 to start parsing
Rows: 0 · Columns: 0
What this tool does
- Turn an exported Excel report into JSON for an API or a script.
- Check whether the values inside an xlsx match what you expect.
- Save one worksheet as CSV for another system.
Example
Input
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
Output
name,age Ada,37.0 Bob,42.0
The input is the base64 text of an xlsx file: the page reads and encodes your local file, while the wasm side only parses.
Frequently asked questions
Is my spreadsheet uploaded?
No. The page reads and encodes the file locally and parsing happens in browser WebAssembly, with no network request.
Which formats work?
Only xlsx (OOXML). xls, ods and csv raise an invalid-xlsx error — save them as xlsx first.
Why do numbers have decimals?
xlsx stores numbers as f64, so 37 comes back as the JSON number 37.0. Format it yourself if you need integers.
How are empty cells shown?
As null in JSON, and as an empty field (nothing between the commas) in CSV.
Keywords：excelxlsxexcel转jsonexcel转csvexcel解析wasm