From source file to a working project.
Jason is designed to be direct: choose the file, let the first import finish, then work from the local project.
Open a supported source
Choose CSV, TSV, or TXT on Free, or a Local Data Suite source on Pro. For workbooks, databases, and Word files, choose the worksheet, table, outline, or document table you need. Keep the tab open until the first import reports completion.
Work from the project
Search and sort the full dataset, edit values, and add supported calculations. Only the visible grid surface is rendered at once.
Reopen without reimporting
Return to the local project on the same browser profile and device. Clearing site storage also clears local Jason projects, so retain the source and important exports.
Export the result
Export to CSV when the work is complete, or export the current view to Parquet with Pro. Treat the export as a new file and validate it before replacing any source data.
Try it on the file you gave up on.
Open an oversized CSV for free. Pro removes Jason's limits and adds structured-data, document, and multi-file Local Data Suite tools.