Convert a spreadsheet into a formatted JSON array of objects, with the header row as keys — ready for an API, a script, or a config file. Parsing happens on your device, not a server.
The tool treats the first row of your sheet as a header and every row underneath as a record. Each record becomes a JSON object whose keys come from the header cells, and the sheet as a whole becomes one array — pretty-printed, so it stays readable in a code review or a diff. A sheet with columns name, email, and plan produces objects with exactly those three keys, which is the shape most APIs, ORMs, and test fixtures expect.
This conversion shows up constantly in development work: seeding a database from a sheet a colleague maintains, generating fixtures for tests, loading reference data into a script, or turning a product owner's pricing table into application config. Retyping that data invites errors, and pushing it through an online service means shipping potentially confidential business information to someone else's servers.
Here the parsing is handled by SheetJS inside a Web Worker, so the workbook is read on your own hardware while the page stays responsive. Nothing from the workbook — not the rows, not even the filename — leaves your machine.
Queue a handful of workbooks and two convert side by side, with a ZIP download once they all finish. Workbooks past about 50 MB are declined before conversion starts, because the entire file has to fit in the browser's memory. There is no account to make, no usage cap, and no paywall between you and the download.
It does not. The JSON is generated by JavaScript executing locally, and the conversion would still complete if you went offline after the page loaded.
The first row is always used as keys, so without a real header your first data row would become the field names. Add a header row before converting to get correct output.
Yes — add them all to the queue. Two run at once, and when everything is finished you can download the results together as a ZIP archive.
Yes. You get a syntactically valid, indented JSON array of objects that can be pasted into code, committed to a repo, or sent as an API request body as-is.
Workbooks over about 50 MB exceed what a browser tab can safely hold in memory, so the tool declines them rather than failing partway through.