What changed
between two revisions
Two PDFs, two scans or two photos of the same plan: the tool aligns them on each other and highlights what was added, what disappeared and how big the change is.
Both images are overlaid automatically, even when the framing differs.
Two distinct colours: what appears in revision B, what disappears from revision A.
A percentage of changed pixels gives the size of the change in one number.
Revision C lands, and nobody says what moved
A new print arrives by email marked minor update. Two partitions moved, a door swapped its swing, a duct appeared. Nobody wrote it down, and the quote sent last week rests on the old plan.
Visual comparison settles it in thirty seconds. The two versions are aligned, the difference is painted on top, and you see exactly where to look before re-running an analysis or fixing a price. The images stay the ones you supplied: nothing is redrawn.
What the comparison shows
Aligned overlay
Both versions are aligned before comparison, so a scanning offset does not create false differences.
Additions layer
Everything present in the new revision and absent from the old stands out in a dedicated colour.
Removals layer
What disappeared appears in a second colour, usually the hardest thing to spot by eye.
Change figures
Percentage changed, share added and share removed: enough to judge whether the pricing must be redone.
Side-by-side view
The two revisions can be examined separately or merged, depending on what you want to show.
Exportable image
The overlay downloads so you can attach it to a query email or a meeting report.
Plan comparison questions
Do both files need the same size?
No, the alignment handles differences in framing and display scale. Two plans that do not show the same area will give an unreadable comparison though: this is a tool for successive revisions, not for different storeys.
Can I compare a scan with a vector PDF?
Yes. The comparison works on the rendered image of both documents, so the origin of the file hardly matters. A scanned print against a recent PDF export is in fact the most common case in renovation work.
Do I need to re-run the analysis afterwards?
It depends on the size of the change: below a few per cent of pixels changed, a local fix to the takeoff is often enough. Above that, re-running the analysis on the new revision costs thirty seconds and gives you complete, current quantities.
Other features
Comparisons
Use cases
From the blog
Check the latest revision you received
Load the old and the new plan and see in thirty seconds what the email did not mention.