How to open an XLSX file online without Excel
Open and edit .xlsx workbooks in your browser with GridCraft: formulas, formatting, charts and PivotTables, with nothing uploaded. Plus what it can’t open yet.
GridCraft guides
Short, practical walkthroughs for the browser spreadsheet.
Convert CSV to XLSX online, free and private
Turn a CSV or TSV file into an Excel workbook in your browser: GridCraft detects the delimiter and encoding, and Save downloads a real .xlsx.
AI formula generator on your own API key
Describe a calculation and get the formula, ask questions about a workbook, or generate a table that opens in GridCraft.
GridCraft MCP: a spreadsheet your agent can drive
Connect Claude Code or another MCP client to the GridCraft command-line tool or the desktop app.