Compare two scans and see what changed

When you have more than one flight of the same property, the Compare tab lets you put two dates against each other and see exactly what moved, grew, or got built between them — no guesswork, no flipping between windows. It all runs right in your browser.

Open Compare

Find the Compare tab (the split-rectangle icon, labeled Cmp on phones) in the row of tabs along the top of the viewer. It shows up whenever your project has a 2D map.

• If your project has only one flight so far, Compare puts a satellite base map on the left and your drone map on the right, with a slider you drag to reveal one beneath the other.
• If your project has two or more flights, you get the full set of comparison tools below.

Pick your two dates

Two chips sit at the top of the view — a Left scan picker and a Right scan picker. Click either one and choose a flight date from the dropdown (each is listed by date and label). You can also choose Satellite Base on a side to hold a flight up against plain satellite imagery.

When you have three or more flights, a timeline appears along the bottom. Each dot is a flight date — click a dot to load it, and the colored band shows the span you're currently comparing.

The two maps stay locked together — pan or zoom one and the other follows, so you're always looking at the exact same spot on both dates.

Choose how to compare

A mode switcher sits in the top bar (keys 1–4 are shortcuts):

• Side by Side — a draggable slider that reveals one date over the other as you slide.
• Before / After — a swipe divider you drag left and right to wipe between the two dates. Nudge it with your arrow keys.
• Difference — a change heatmap laid over the map. Areas that stayed the same read green; areas that changed light up red — the fastest way to spot new construction, cleared ground, or moved material at a glance.
• Elevation Change — a height-difference overlay showing where the ground rose or dropped. Blue is cut (lower), red is fill (higher), gray is unchanged. This mode needs elevation data on both dates.

Use the Overlay Opacity slider to fade the heatmap up or down against the map underneath.

Read the numbers

In Difference and Elevation Change modes, a Change Summary panel gives you real figures: the percent of area changed, the changed area in square feet, and — for elevation — the average and range of height change in feet. You'll get a Full extent figure for the whole property, and in Difference mode a Current view figure for just what's on screen.

Save it and share it

From the Change Summary panel you can export your comparison:

• PDF Report — a clean, branded change report you can hand straight to a stakeholder.
• CSV — the raw change numbers for your own records.
• GeoJSON — the changed area as a map polygon for use in other software.

Tip: If your project is on recurring monitoring, every new flight can produce a change-report link that opens Compare directly in the difference view — the new date versus the one before it — so what changed is the first thing you see.

These figures are engineering-grade mapping meant for planning and tracking progress over time, not a legal land survey.