Family tree application that runs entirely in your browser. No server required, your data stays with you.
Online version: stromapp.info
People & Relationships
- Add, edit, delete persons
- Multiple marriages, divorces, step-siblings
- Birth/death dates and places
- Placeholders for unknown persons
Visualization
- Interactive tree with generation rows
- Zoom (scroll/pinch) and pan (drag/swipe)
- Focus mode - show subset of tree around selected person
- Responsive design (desktop, tablet, mobile)
- Light/dark theme
Tree Management
- Multiple trees in one app
- Rename, duplicate, delete trees
- Smart merge with conflict resolution
- Tree validation (detect issues)
- Tree statistics (counts, age ranges, anniversaries)
- Set default person/tree for startup
Import/Export
- GEDCOM 5.5.1 import (compatible with Ancestry, FamilySearch, Gramps)
- JSON export/import
- HTML file import (extract data from exported Strom files)
- Export as standalone HTML file (works offline)
- Export only focused subset
Encryption
- Optional AES-256 data encryption
- Password-protected exports
Two Ways to Use
| Online Version | Standalone File |
|---|---|
| stromapp.info | Download strom.html |
| PWA - install to home screen | Works offline, no internet needed |
| Data in browser storage | Data in browser storage (separate) |
| Always latest version | Version frozen at download time |
Note: Online and standalone versions use separate storage. To transfer data between them, use JSON export/import or import the HTML file directly.
Other
- Person search (live search + URL parameter)
- English and Czech language
- Offline support (PWA)
Visit stromapp.info and start adding your family.
Download strom.html from Releases and open in any browser.
git clone https://github.com/ACiDekCZ/strom.git
cd strom
npm install
npm run build
# Output: strom.html- Add Person - Click "+ Add Person" or use the button on empty state
- Edit Person - Click on any person card to edit details or manage relationships
- Navigate - Drag to pan, scroll to zoom, or use zoom controls
- Focus - Click person → "Focus" to see only their immediate family
- Export - Menu → "Export App" to save your tree as portable HTML file
- Import - Supports JSON, GEDCOM, and Strom HTML files
- TypeScript with strict mode
- esbuild for bundling
- No runtime dependencies
- Single HTML file output (~550kb)
- Works offline in any modern browser
- Progressive Web App (PWA) support
npm run watch # Dev mode with auto-rebuild
npm run build # Production build
npm run typecheck # Type checking
npm test # Run testsThis project uses a dual license model:
- Non-commercial use: Mozilla Public License 2.0
- Commercial use: Requires separate agreement. Contact: milan@stromapp.info
See the LICENSE file for details.
Milan Víšek - stromapp.info
Strom - Your family history, always with you.