What is PDF Reviewer? PDF Reviewer is a cloud-based document collaboration platform designed for engineering, architecture, and construction teams who need to review technical drawings, contracts, and specifications together. Unlike traditional PDF tools that require desktop software, PDF Reviewer runs entirely in your web browser—making it accessible on Mac, PC, and Linux with zero installation. What makes us different: We solve the chaos of email-based document reviews. Instead of tracking 15 different versions of "Drawing_Final_v3_ACTUAL_FINAL.pdf," your team comments directly on a single shared document. Comments are spatially anchored to exact locations on the PDF, so there's never confusion about what someone's referring to. Built for teams, not individuals: PDF Reviewer includes approval workflows (Preparer → Reviewer → Approver), @mentions for notifications, threaded comment discussions, and complete audit trails showing who said what and when. Every action is tracked and immutable—critical for compliance-driven industries. Beyond PDFs: We're the only review platform with native 3D STEP file support. Upload STEP models directly from SolidWorks, Fusion 360, or any CAD tool (up to 500MB) and annotate them with the same commenting tools you use on PDFs. No conversion to 3D PDFs required. Pricing that makes sense: The first 2 seats are free forever. Additional users are $9/month—67% cheaper than Bluebeam Revu. No contracts, no credit card required to start, and all users get the full feature set. We believe great document review shouldn't cost $330/user/year. Who uses PDF Reviewer: Architecture firms reviewing drawing submittals. Manufacturing teams approving ECNs and technical specifications. Construction companies tracking RFIs and change orders. Any team that needs to review documents collaboratively with accountability and audit trails. Real-time collaboration: See who's viewing the document right now. Get instant notifications when comments are added or resolved. Track review progress with visual dashboards showing completion status. It's document review that actually feels modern.