Polygon Editing Suite

Resize and general

Drag the bar beside the Polygons panel to resize it (arrow keys when it has focus; double-click resets). Everything is also in the toolbar on the map and the right-click menu. Polygons are saved in this browser only.

Basics

Click	Click a polygon to edit it: drag corners, drag a midpoint to add a corner (or double-click a side to add one right there), drag the move handle (four arrows) to move it, the rotate handle (circular arrow) to rotate it (hold Shift to snap to the step set in Settings). Enter or Esc finishes; Delete removes it.
Right-click	Menu: square / round corners, extrude, slice, carve, merge, reference line.
`Esc`	Esc (when nothing is selected): hide or show the reference line.
Undo / Redo	Undo (`Ctrl+Y` or Shift+`Ctrl+Z` redo).
Units	Settings > Units: US (ft, ft²; acres from half an acre; the default) or Metric (m, m²). It changes every length and area shown and the array and Shift step sizes; the polygons themselves are always stored and exported in metres.

Phone and tablet

On a phone or tablet: tap to place points (Rectangle, Extrude and the other tools take taps, then the bottom bar's Finish). Drag a corner to move it; drag a midpoint to add a corner. Long-press the map for the menu. The bottom bar has Finish, Cancel, Undo, Redo, Back and Delete. Pinch with two fingers to zoom.

Draw	Draw an outline: click corners, click the first point (3+ corners), double-click or Enter finishes, Backspace undoes a corner, Esc cancels. Shift = 45-degree steps, Ctrl = no snapping.
Rectangle	Rectangle: click two corners, pull to the width, click. Shift = 45-degree steps (and rounds the width), Ctrl = no snapping.
Circle	Circle (toolbar): click the two ends of a diameter. Hold `Alt` while setting the radius to draw from the center (the first click is the center). Shift = 45-degree steps, Ctrl = no snapping.
Extrude	Extrude / indent: edit a polygon, click two points on a side, pull, click. Shift rounds the distance, Ctrl = no snapping.
Slice	Slice: click a line across a polygon (the edited one, or every polygon the line splits when none is edited), Enter or double-click slices. Rays (`I`) extend the line endlessly.
Carve	Carve: click the corners of a shape, Enter or double-click removes it from every polygon it overlaps (it must reach a polygon's edge).
Copy outline	Copy outline (also the toolbar Copy outline button and right-click menu): hover a polygon on any layer that is switched on, drawn or imported (such as a City footprint); the nearest edge within 10 px wins, else the smallest outline around the cursor; it lights up white; click copies it as a polygon opened for editing. Esc cancels.
Array	Array: copies the polygon being edited (or the one you click) into rows and columns. The wheel = column gap (`Alt`: row gap; 1 cm / US 1 in per step, `Ctrl`: 1 mm / US 1/16 in; `Shift`+wheel zooms the map); arrows = rows / cols, click a line or edge to run the columns along it (`Ctrl`+click: free direction), click or Enter places, Esc cancels. Afterwards drag the handles in the gaps to change one gap, or the master handle past the grid end to space all gaps equally (drag freely, no steps; `Ctrl`+drag moves the gap at a tenth of the mouse speed; `Shift`+drag snaps to 0.1 m / 1 ft; double-click or `Enter`: average). Wheel over a handle, or Tab to it and use the arrows: 1 cm (US 1 in); `Ctrl`: 1 mm (US 1/16 in); `Shift`+wheel zooms the map. A whole selected array shows only its thin dashed frame. In the Polygons list, groups fold away and the pencil (or double-click) renames a polygon or group. Clicking any copy selects the whole array (like a group): arrows nudge all copies, Delete removes all (after the confirm), Ctrl+click toggles the whole array. Double-click a copy to edit that one polygon; Esc goes back to the whole array, Esc again clears. The selected array has a dashed frame: drag the frame or its inside to move it, drag the round knob above its top edge to turn it about its center (`Shift` snaps to the Settings angle step, 15° by default), drag a corner handle to scale it, polygons and gaps together, about its center (`Alt`: about the opposite corner); Esc during the drag cancels it; while you drag the frame, knob, a corner or a gap handle, the original shapes fade to 30% so the dotted preview stands out. Ctrl+Z undoes the whole array.
Curves	Side types (Line while drawing, Arc, End arc, Bézier, Tangent) are in the bottom bar while drawing or with one side selected (or right-click a side). Arc and End arc (like the ArcGIS endpoint arc): click the end point, then move the cursor: the arc follows it with both ends fixed, and a second click sets the point the arc passes through (on a selected side, one click). Bézier: click the end, then two pull points. Tangent: click the end (continues the previous side’s direction). Esc drops the pending clicks.
Skewed extrude	Extrude: after the first point, press `Alt` to lock the second point, move the mouse left / right to set the skew angle, click to confirm. The far side passes through the clicked point.
Skewed rectangle	Rectangle: after the first corner, press `Alt` (or the Skew button) to lock the second corner, move the mouse left / right to set the skew angle, click to confirm, then pull out and click: the result is a parallelogram.
Taper	Select two sides (click, Ctrl+click), then `Alt`-drag a corner of one of them: both sides tilt together.

Auto merge

Auto merge (toolbar switch or right-click > Auto merge): a polygon you draw, rectangle or copy that overlaps or touches another polygon is merged with it into one (one Ctrl+Z undoes both); refused when it only touches at a corner or would leave a hole. Merge tolerance (right-click menu; pick the unit with the unit button, default 0, max 50 cm / about 20 in) also joins shapes that are that close.

Editing tools

Explode	Explode array: with one whole array selected, turns its polygons into plain polygons (also the Explode button on the array heading and right-click > Explode array). Ctrl+Z undoes.
Group	Group: with two or more polygons, arrays or groups selected, ties them into one group (also the Group button, `Ctrl+G`). Click a member to select the whole group; move, rotate and scale act on it as one. With exactly one group selected it ungroups. Ctrl+Z undoes.
Merge	Merge: click one polygon, Ctrl+click others, press `G` (or right-click > Merge).
Several polygons	Ctrl+click polygons (on the map or in the Polygons list) or Ctrl+drag a lasso on empty map: every polygon whose center is inside is added. The toolbar Select group (click and hold, or its corner triangle) picks Lasso, Box or Line-crossing: then a plain drag on empty map selects (Shift adds, Esc ends); a line selects every polygon it crosses. Then drag one to move them all, arrows nudge (Shift ×5), [ ] rotate, Delete asks once, `G` merges. Esc or a click on empty map clears. Alt = alternate, Ctrl = free / multi-select, Shift = snap. The count is announced in the Status line.
Sides	Click a side; Ctrl+click toggles a side; Ctrl+drag lasso adds sides, Alt+drag lasso removes sides (start on an empty spot of the map); drag to move them.
Edge snap	Moving a polygon (move handle, frame or several at once), scaling it, dragging a side or a corner snaps its corners and sides onto the corners and edges of other polygons (and imported layers) within about 9 px; pull further and it lets go. Hold `Ctrl` for no snapping. Hold `Shift` while dragging a corner or side to snap it onto a neighboring polygon's corner first, else its nearest edge (within 10 px).
Align sides	Select sides, set a reference line, right-click > Align sides to reference line: each side turns about its middle to parallel or perpendicular, whichever is closer.
Straighten	Right-click a curve > Straighten this curve turns it back into one straight side. Dragging a curve’s end re-fits it; editing inside a curve flattens it to corners.
Arrows	While editing: nudge by the step set in Settings (Shift: 5 times that), the selected corner if one is selected (click it); with sides selected, each side moves along its own axes (along and across it; Shift: 5 times); `Ctrl`+arrow (Cmd on a Mac) nudges the same selection (sides, a corner or the whole polygon) straight along the screen: up is north, right is east, whatever the side direction. `[` `]` rotate 0.5 degree (Shift: 2 degrees).
Hide	Hide / show your outlines.
Check	Check (bottom bar while a polygon is edited or selected): marks overlaps in red and gaps under 0.3 m in yellow. Click a highlight to zoom to it; Clear check removes them.
History	History button: every undo step with its time; click one to go back to it.

Reference layers

Import reference layer (Layers panel): view and snap to a GeoJSON/JSON file, a zipped shapefile or an ArcGIS REST layer address (ArcGIS Online, gis.nola.gov, maps.nola.gov or eocgis.nola.gov only). Imported layers are not editable, show only what lies inside the image, and are gone when you reload; the Hidden snap switch also covers them. Q copies an imported polygon's outline.

Imagery site

Imagery site (Layers panel): the Imagery button switches between the RPC 2026 site and the Cemetery site; your polygons stay as they are, and the choice is remembered in this browser. Each imagery site keeps its own drawings.

Drawn layers

Drawn layers	Layers panel, Polygons: each drawn layer has its own color, a show switch, a Fields button and a remove x (only while it holds no polygons). Click a name to draw on that layer; the Layer select in the bottom bar moves the selected polygons to another layer.
New layer	New layer adds another layer to draw and edit polygons on. Import reference layer adds a file or ArcGIS layer for viewing and snapping only (not editable, not saved).
Fields	Fields (the button on a layer row): define extra columns for that layer (text, number, date or choice). Every polygon on the layer then has them.
Attributes	Attributes (boxed under the edited row in the Polygons list): Name, Notes and the layer's fields for the one selected polygon. Each change is one undo step.
Skeleton view	Skeleton view: cycles off, white, black. Your polygons show as a thin dotted outline with a faint fill (display only); handles stay usable. Also the Skeleton toolbar button.
Guide rays / Lock ray	Guide rays on / off; lock the ray direction (Esc unlocks).
Google Maps / Pictometry	Open Google Maps, Pictometry (Assessor Beacon) for the polygon being edited, else the map center. Opens a new window; nothing is embedded.
Export	Export GeoJSON: saves the active layer only (EPSG:6344); polygons on other layers are not in the file.

Edit an ArcGIS Online layer

Sign in with your ArcGIS account, then load a polygon feature service layer as an editable layer with its own fields. Your edits stay in this browser until you save them.

In the Layers panel, choose + by Drawn layers, then From ArcGIS Online, then Sign in with ArcGIS (the page reloads and returns here; Sign out forgets it on this browser tab).
Paste an item address, a 32-character item id or a .../FeatureServer/<n> layer address and choose Load. If the service has several layers, pick one and choose Load layer.
Only single-ring polygons load (a polygon with holes or several parts is not editable here), and at most 2,000 features inside the image.
Edit as usual. The layer row shows Save to ArcGIS (n), n being the unsaved changes. It asks you to confirm, naming the layer and the counts of features added, updated and deleted. Ctrl+Z cannot undo a save.
If a save fails part way (uncertain), Save to ArcGIS is disabled for that layer: load the layer again from ArcGIS before saving again.

Customize the toolbar

Toolbar: tools that do not fit move into the More (...) menu at its right end. More > Customize toolbar (or right-click > Customize toolbar) lets you show, hide and reorder tools (drag, or the arrow buttons); hidden tools still work from the right-click menu and their keys. Saved in this browser.

Polygon Editing Suite - demo

Settings

App

Selection

Segments

Reference line

Array grid

Handles

Add layer

New layer

Fields

Import reference layer

Reference layer

Edit an ArcGIS layer

Delete polygon?

Help