Drag a .geojson, .json, .tif, or .tiff file anywhere on the map to add it straight away, choose one below, or paste GeoJSON in the box.
Vertexer is a spatial data tool for Humanities projects that need to create, edit, and export geographic features in GeoJSON or TEI XML format, and overlay georeferenced historic scans (GeoTIFF) for tracing or comparison against a modern basemap. It supports vector tile layers, geodesic measurement, and an extensible gazetteer registry for place-name search.
Vertexer was developed in the Humanities Computing and Media Centre by Greg Newton.
Vertexer lets you create, edit, and export spatial features (points, lines, polygons) for Humanities projects using TEI XML or GeoJSON output. Search multiple gazetteers to find and import existing place geometries, draw your own, or drag-and-drop a GeoJSON or GeoTIFF file.
The Drawing toolbar draws points, lines, and polygons, and provides merge/subtract/undo controls.
The Action cluster imports, exports, zooms, clears, and downloads a map image.
Search queries gazetteers; results can be added as points or in their original geometry.
The Legend shows map centre, cursor position, and zoom.
Drag a georeferenced .tif or .tiff onto the map, or choose one
from the Import panel, to add it as an overlay.
Overlays draw beneath your features, so you can trace directly over a georectified scan.
Files must be in EPSG:4326 or EPSG:3857, 8-bit, and north-up. Anything else is refused
with a note on how to convert it — reproject in QGIS, or with
gdalwarp -t_srs EPSG:3857, first. Large rasters are downsampled to fit;
ones beyond what the browser can decode are refused. Transparent edges in the source
stay transparent, so a scan's black collar will not hide the basemap beneath it.
Manage overlays in the Layer panel (Alt+L): set opacity or remove. With more than one overlay loaded, the arrows beside each name move it up or down the stack; the list reads top-down, so the first row draws over the rest.
Overlays appear on the primary map, the secondary map, or both. That is one setting for every overlay at once — see Settings, above. Send them to the secondary map, choose a modern basemap as the primary, and drag the swipe bar to compare the two. With no secondary layer active, overlays sent to it are simply not drawn until you pick one.
Overlays last for the session only. They are not saved in the URL and disappear when you reload.
Click a feature to edit it, and its vertices appear as handles. Click one to select it, Shift+click more to add them, or Shift+drag a rectangle to add every vertex it touches at once. There is no separate tool to turn on — the rectangle is just another way of building the same selection, so the three can be mixed freely.
Dragging any selected vertex moves the whole selection together. Delete or Alt+X removes all of them in one undoable step. Removing vertices never leaves a broken shape behind: a line dropped below two points, or a polygon ring below a triangle, takes its feature with it rather than leaving an invalid geometry on the map.
To add a vertex, double-click (or Ctrl+click) anywhere on a line or polygon edge — the new vertex lands at the nearest point on that edge, and the feature stays in edit mode so you can drag it straight away.
A rectangle only picks up vertices of the feature you are editing. With no feature under edit, Shift+drag keeps its usual meaning of selecting whole features.
Snapping is active by default — vertices and edges of existing features will attract the cursor. Hold Alt to bypass snapping for a single placement.
Double-click to finish a polygon or line. Press Esc to finish and deselect.
Click a feature to select it and open the info popup.
Undo (Ctrl+Z) covers all draw and edit operations.
The URL updates automatically with your current view. Bookmarkable parameters:
c=lng,lat — map centre (EPSG:4326)z=12 — zoom levelp=3857 — display projectionl=basic — primary layer keys=sat — secondary layer keyg=osm — geocoder providerb=ca — region preset