Files and offline use
Sail Design keeps your design in the browser while you work. To keep it for a later session, save a JSON file to your own device. There is no autosave, server-side design library, or cloud recovery copy.
Save a design
Choose File > Save or press Cmd/Ctrl+S.
- In Chrome, Edge, and other browsers that support the system file picker, the first Save asks for a location. Later saves in the same session overwrite that file. File > Save As always asks for a new location.
- In Firefox and Safari, Save downloads a new file. Save As asks for a filename and then downloads it.
- Cancelling the picker or filename prompt leaves the design open and unchanged.
The default name combines the sail type with the local date and time, such as gennaker-20260730-143012.json. You can rename the file without changing its contents.
The filename in the app gains a • when the current design has changes that have not been saved. A successful Save removes that mark.
Keep the downloaded file
The JSON file is the recoverable copy of your design. Closing the tab without one can permanently lose the work.
What the file keeps
A saved file keeps the settings that define the design:
- sail type and dimensions;
- edge shape, section profiles, twist, and mould controls;
- cloth and construction settings;
- panel layout; and
- panel colour choices.
The current Fullness multiplier is applied to the saved section depths, then returns to 1.00×. Reopening the file therefore reproduces the effective shape you saved.
Generated flat panels are not stored in the file. Neither are the current camera, workspace, visible layers, account session, or Apply postprocess choice. Generate panels again after opening if you want to view or export them.
Open a saved design
Save the design currently on screen
File > Open does not ask before replacing an unsaved design. Save the current work first if you may need it again.
Choose File > Open (Cmd/Ctrl+O)
Select a JSON file previously created by Sail Design. A successful open restores the saved shape, cloth, construction, layout, and colours, then recalculates the preview and seam overlay.
Generate panels again when needed
Opening clears any earlier generated panel set and its warnings. Choose Panels > Generate Panels before returning to the panel viewer or a panel-based export.
After Open, the next Save asks for a destination even in a browser that can overwrite files. Opening a file does not give the app permission to write back to that same file.
Supported sail types
Files for all nine sail types can be saved and reopened:
- Gennaker
- Code 0
- Genoa 135%
- Working jib
- High-aspect jib
- Symmetric spinnaker
- Mainsail
- Storm jib
- Storm trisail
The loader also updates several older Sail Design file formats automatically, including former chord, rig, twist, colour, layout, and headsail-tack data. If a file is not a recognised Sail Design file, the app shows a load error: banner instead of partly loading it. Do not edit the JSON to work around that message; return to a known copy or create a new design.
Protect unsaved work
The app handles replacement actions differently:
| Action | Current warning |
|---|---|
| File > New while the design is changed | An in-app confirmation asks before starting over. |
| Reloading or closing a changed tab | The browser can show its native leave-page warning. |
| File > Open while the design is changed | No confirmation; the selected file replaces the design immediately. |
Save before any of these actions. If the tab has already closed and no saved file exists, the app cannot restore the design.
What works without the backend
Once the app page has already loaded, these design-time actions run in the browser:
- create, shape, and inspect a sail;
- use the 3-D, 2-D, and Heatmaps workspaces;
- preview all five panel layouts and their seams;
- edit profiles and Tri-radial colours; and
- save and open local design files.
These actions need a connection to the Sail Design backend:
- Generate Panels; and
- every DXF, PDF, and SVG export.
This is not an installed offline app: loading the site for the first time, or reloading it after browser data has been cleared, can still require a network connection. Sign-in is covered separately in Sign-in and account.