Multiple sheets
Create editable grids with multiple tabs, resizable rows and columns, and a dedicated context menu.
Beta · Version 0.5.0 available now
LumeSheets
Calculate locally. Keep control.
A fast local-first spreadsheet for everyday and intermediate work, with formulas, multiple sheets, XLSX and CSV support, local autosave and no mandatory account.
No accountLocal-first dataWorks offline
B4fx
=SUM(B2:B3)A
B
C
D
1
Category
Value
Status
Notes
2
Hosting
35.00
Paid
August
3
Domain
40.00
Paid
Annual
4
Total
75.00
Overview2026
53Available functions
3Interface languages
0Mandatory uploads
PWAInstallable and offline
A capable spreadsheet without the platform overhead
Build, calculate, import and export directly in the browser.
LumeSheets combines familiar spreadsheet tools with local storage and portable files.
Formulas and references
Use 53 supported functions and select cell references with the mouse while editing formulas.
Practical formatting
Apply number, currency, percentage, date and time formats to present data clearly.
XLSX, CSV and backups
Import and export XLSX or CSV, and preserve complete workbooks in the portable .lumesheet format.
Local autosave
Workbooks and preferences are saved automatically in the current browser.
Themes, languages and PWA
Use light, dark or automatic themes in English, Portuguese or Spanish, with installable offline support.
Local by design
Your workbook is not silently uploaded.
LumeSheets stores workbook data and preferences in the browser. Core editing, calculations, imports and exports run locally on the device.
Create a workbook→Calculate locally→Export or back up
Keep backups of important work.
Clearing site data, switching browsers or changing devices can remove locally stored workbooks. Export a .lumesheet backup regularly.
Inspect and host it yourself
The complete LumeSheets 0.5.0 beta package is available.
The release is a static local-first web application with PWA support. It can run on ordinary HTTPS hosting or a local web server.
SPDX-License-Identifier: AGPL-3.0-onlyClear beta scope
A strong everyday spreadsheet, not a complete Excel replacement.
Version 0.5.0 does not include VBA macros, Power Query, Power Pivot, pivot tables, real-time collaboration, advanced charts or perfect compatibility with complex XLSX files.
LumeSheets FAQ
Before you begin.
Do I need an account?
No. Open the application and create a workbook immediately.
Which files can it use?
It imports and exports XLSX and CSV, and uses .lumesheet for complete portable backups.
Will every Excel workbook look identical?
No. Simple and intermediate workbooks are the focus; complex Excel-specific features may be unsupported or imported with limitations.
A spreadsheet ready in the browser
Open LumeSheets