One focused utility

About Celljson

Celljson helps with a small but common handoff: a spreadsheet-style comma-separated table needs to become JSON without guessing what its cells mean. An identifier with leading zeroes may look numeric but still be an identifier. A cell containing null may be a literal word. Keeping all cells as strings leaves those decisions with the person using the data.

The tool offers two explicit shapes. Arrays retain every record and column position. Objects use one validated header record and retain the remaining records. It does not group rows, sum values, compare lists, deduplicate a table or infer a schema. That narrow purpose makes the conversion easy to inspect.

Design choices you can check

Conversion happens only when you choose Convert. Editing the input or output shape clears the previous JSON, table preview, summary and export controls. Reset restores a fixed public example. Every current export contains the full validated result, even when the preview is showing only one page.

The guide documents the declared CSV subset and resource limits. Broken quotes, ragged records and duplicate object headers produce a visible error. The parser preserves its received JavaScript string, while the browser textarea may normalize pasted newlines before that boundary. There is no claim to preserve original file bytes or support every spreadsheet export dialect.

Free use and contact

This is one independent free website with one converter. No account or payment is required to use it. This release loads the exact-host Cloudflare Web Analytics script for page-usage and performance telemetry. Conversion runs locally, and the converter does not build pasted CSV into analytics events, page URLs or remote conversion requests. Advertising and consent-platform loaders are inactive. Source configuration is separate from advertising approval or income.

A shared public forwarding alias handles optional feedback. If you report a conversion issue, a short invented example is more useful than a confidential table. Include the output shape and the expected result. The contact page explains the shared address, and the privacy page explains the local processing boundary.