Free Microsoft Excel Alternative — Online Spreadsheet
A complete Excel-style spreadsheet that runs entirely in your browser: hundreds of formula functions, charts, conditional formatting, and real .xlsx workbooks. Nothing is uploaded — your data stays on your own device.
GridCraft
An Excel-style spreadsheet with formulas, charts, and native .xlsx files - no install, no upload.
First launch downloads ≈7 MB, then it's cached for a year. Nothing is uploaded — your files stay on this device.
This is a desktop-class app — it works best on a larger screen.
Quick Answer
This free online spreadsheet gives you the core Excel workflow in a browser tab: hundreds of built-in formula functions, cell and conditional formatting, charts, filters, and multi-sheet workbooks with freeze panes. It opens and saves real Excel .xlsx files that round-trip with desktop Excel. The engine is a Rust formula evaluator compiled to WebAssembly running on your device — spreadsheets are never uploaded to any server.
How It Works
Open and Launch — Open the spreadsheet page in a desktop browser and click Launch. The first launch downloads about 7 MB; after that it is cached.
Open or Start a Workbook — Open an existing .xlsx through the file picker, or start a blank workbook.
Enter Data and Formulas — Type values, build formulas with the function catalog, and add formatting, charts, and filters.
Save Your .xlsx — Save the workbook as .xlsx to your device — it opens directly in Microsoft Excel too.
Key Facts
- Real .xlsx open/save with formulas and formatting intact
- Hundreds of built-in functions
- Charts, conditional formatting, and filters
- Multi-sheet workbooks with freeze panes
- Keyboard-first navigation (Enter, Tab, arrows)
- No account, no upload, no watermark
Frequently Asked Questions
Is this really free, and do I need an account?
Yes — completely free, no account, no watermarks. The underlying software is open source under Apache-2.0, embedded exactly as published.
Are my spreadsheets uploaded anywhere?
No. The whole application runs as WebAssembly inside your browser tab; data entry, recalculation, charts, and saving all happen on your device.
Does it work with real Excel files?
Yes — it opens .xlsx workbooks with values, formulas, formatting, and charts, and saves .xlsx desktop Excel reads. Very exotic Excel features (VBA macros, Power Query) are not supported.
Which formula functions are supported?
The catalog covers the everyday working set: math, statistics, text, date and time, lookup and reference, logical, and financial functions. Anything you would use for budgets, models, and data cleanup.
Does it work on mobile?
It runs on modern mobile browsers, but spreadsheet editing wants a desktop screen and keyboard for real work. For one-off number crunching on a phone, the site calculators are faster.