Open files or drag them onto the map (GeoPackage, shapefile, GeoJSON, or a .zip of these), Connect to a data provider's API, or Open folder… (Chrome / Edge) to save edits straight back to the files.
Click a layer's features to list their attributes in the right-hand panel. The colour square opens the layer's style; ☰ its attribute table; drag a layer row to change the order.
Edit: press “Edit” under a shapefile or GeoPackage line layer (only line layers can be edited). Then click a line. Drag a vertex to move it, click a mid-point handle to add one, right-click a vertex to remove it. “Move” drags the whole line.
Draw a line: use the pencil tool (top-left of the map). Click to add vertices, click the last vertex to finish. Lines snap to other lines.
Delete: select a line, then Delete (twice to confirm) or the Del key. “Undo delete” restores the last deleted line.
GeoPackage: layers can be opened and edited, but a GeoPackage is read-only: saving downloads the edited layer as a zipped shapefile.
Save: “Save to files” writes the .shp/.shx/.dbf back into the opened folder (original backed up in _backups); otherwise it downloads a .zip.
Measure (ruler button on the map): click points, double-click to finish; Esc clears.