Data & JSON

Excel / CSV to JSON

Convert Excel, UTF-8 CSV and pasted tables to JSON locally. Select XLSX worksheets and header rows, preserve strings, optionally convert types, preview, copy and download.

About this tool

Paste cells copied from Excel or import a UTF-8 CSV or XLSX file. Select a worksheet and header row to generate a JSON array of objects. Processing stays in your browser.

Best use cases

  • Prepare configuration tables, business data or test fixtures for JSON-based APIs.
  • Keep leading zeros and long identifiers intact instead of silently coercing them to numbers.

How to use it

  1. Paste data with column headers or import a CSV / XLSX file. Select a worksheet for XLSX.
  2. Choose the header row, delimiter and type settings, then convert. All values remain strings by default.
  3. Review the source preview and result, then copy or download JSON. Column names must be nonempty and unique.

FAQ

What are the size limits?

Up to 10 MiB, 10,000 rows, 200 columns and 200,000 cells per run. CSV uses UTF-8. Oversized tables report an error instead of silently truncating data.

How are formulas and dates handled?

XLSX uses existing formatted cell values and cached formula results without recalculation. Dates remain display text. Precision already lost in Excel cannot be recovered.

How does this differ from JSON to CSV?

This tool imports tables into a JSON array of objects. JSON to CSV exports in the opposite direction. Blank rows are skipped and missing cells become empty strings.

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