Vehicles, contracts, finances, inventory — all in a single modular app.
Your data stays on your device. Always.
No credit card · No mandatory account for the Free plan
Every module is designed for a real need. Activate only the ones you use, pay only for the active ones.
No server installation, no mandatory account to get started.
Sonnet is local-first: all data is saved exclusively on your device. There are no servers storing your company or client information.
Single-activation modules. Change your plan whenever you want. No hidden costs.
Choose from: Hobby · Business · Creative · Freelance · Commerce · Finance
All prices include VAT · Cancel at any time · No charge without consent
Answers to the most frequent questions. Can't find what you're looking for? Write to us.
No. All operational data (vehicles, contracts, finances, clients, etc.) is saved exclusively in your browser's localStorage. It does not pass through any external server. The only communication with the backend concerns license validation: the server checks that the key is valid and replies with the active plan. It neither knows nor receives your company data.
Sonnet is a Progressive Web App (PWA): you use it directly in your browser, with no mandatory installation. On mobile and desktop you can add it to your home screen for an experience similar to a native app. It also works offline after the first load.
Data is local, so it doesn't move automatically between devices. However, you can export a JSON backup with one click from the sidebar and import it onto any other device in seconds. A cloud sync module is planned as a future premium feature, without ever removing local mode.
The license is tied to the email you purchased with. The key can be activated on a limited number of personal devices. Commercial sharing is not allowed and leads to automatic revocation. The 3 Modules plan includes the ability to use the app on multiple devices belonging to the same professional.
Yes, upgrading is instant. In case of a downgrade, the modules become inaccessible but the data is never deleted — it's still there, waiting for you to come back. You don't lose any data by changing plan.
For the first launch, yes (to load the app). After that, it works completely offline. The only operation that requires the internet is the periodic license activation/check — a lightweight request about every 7 days. All data is accessible even without a connection.
Free on Dashboard and Tasks forever. Unlock the modules you need when you're ready.
No credit card required · No mandatory account for the Free plan