Stack up to five PDF layers, mark up with revision clouds, NURBS curves and calibrated dimensions, collaborate in real time, and track review approvals - all from your browser. Built for architects, engineers, and construction professionals.
Purpose-built for comparing revisions, marking up drawings, tracking approvals, and collaborating in real time - all from your browser.
Stack up to five PDF layers per sheet - a base drawing plus four overlays. Control visibility and opacity independently per layer. Override linework colour on any layer to instantly distinguish revisions. Layers auto-name from the PDF filename, or rename them yourself.
Revision clouds, rectangles, circles, ellipses, diamonds, triangles, polylines, arcs, NURBS and Catmull-Rom splines, freehand pen, highlighter, and image overlays. Convert segments between lines and arcs, polylines and splines - all with per-annotation colour, weight, dash style, and fill controls.
Set a known dimension or paper scale, then measure anything at true scale. Editable geometry properties - radius, diameter, circumference, area, arc length, sweep - update the drawing in real time. All labels are draggable with configurable font size and background.
Resizable word-wrapping text boxes with frame borders and fill. Arrow leaders with four arrowhead styles - filled, open, dot, and circle. Configurable shop drawing examination stamps that scale from A4 to A0. Count markers and issue status badges round out the annotation set.
Invite collaborators to review drawings together in real time. See live cursors, shared annotations, and presence indicators. Role-based access with host and guest permissions. Annotation layers let team members organise markups independently.
Set annotation status - Pending, Accepted, Rejected, For Review - and track approvals across your drawing set. The project dashboard surfaces a review summary showing status counts, dates, and progress at a glance. Export a full markup summary as CSV.
Upload entire drawing sets at once with drag-and-drop column ordering. When new revisions arrive, bulk re-link by filename - all annotations stay in place. Export as annotated PDF, annotations-only PDF, or flattened PDF. Choose your filename and save location on every export.
Works in any modern browser on Mac, Windows, or iPad. Nothing to download, no plugins, no IT department. Your projects live in the cloud - pick up where you left off from any device. PDF exports match your screen display exactly, including layer visibility and transparency.
You shouldn't need a $600/year desktop application to compare two PDFs.
Drop in a base PDF and one or two overlay revisions. Batch upload handles entire drawing sets at once.
Adjust layer opacity to spot differences. Set a known dimension to enable true-scale measurements across the drawing.
Add revision clouds, dimensions, text notes, arrows, shapes - the full toolkit. Everything is editable and repositionable.
Export annotated PDFs for distribution, or save the .overlay project file to return and continue later.
One plan. Everything included. No tiers, no feature gates, no hidden costs.
Five-layer overlays, advanced curves, calibrated measurements, real-time collaboration, and review tracking - without installing a thing.