Mac workflows · PDF review
How to compare engineering PDF revisions on a Mac
To compare PDF revisions on a Mac, start by confirming the two source issues, matching the correct sheets and checking their alignment. Then inspect the differences and save an annotated record that another reviewer can follow. The comparison output helps locate changes; the engineering review determines their significance.
- Match drawing identifiers and revisions before comparing page images.
- Check alignment and source quality before trusting a difference highlight.
- Hand over both the findings and the source versions used to produce them.
Prepare the two source issues
Keep unchanged copies of the original PDFs and use separate files for review markups. Record their document identifiers, issue dates and revisions in the review note. Choose a naming convention that identifies the package, sheet and revision, while retaining the original document-control information.
For a drawing set, compare the sheet registers first. Match by drawing number and sheet identity. Added, removed or renamed sheets need explicit handling; pairing page 14 with page 14 can compare unrelated content after a set has been reorganised.
Choose the comparison method for the document
For a short review, opening both PDFs alongside each other and marking findings may be sufficient. Apple’s Preview supports notes, shapes and text annotations, so it can be used to record a manual review. For dense drawing packages, look for a tool with revision comparison and overlay views, then assess its output against representative project sheets.
Apple Preview guide: annotate a PDF on Mac
| Method | Useful for | Check before relying on it |
|---|---|---|
| Side-by-side review | Reading notes, schedules and local details in context. | Both views show the matching sheet and location. |
| Overlay view | Locating moved, added or removed drawing elements. | Rotation, scale, crop and alignment are comparable. |
| Text comparison | Inspecting wording changes in selectable text. | The text was extracted accurately and page context is retained. |
Check alignment before interpreting the highlights
Inspect the page size, rotation, crop and drawing scale in both files. Use stable features, such as an unchanged grid intersection, to confirm that equivalent content lines up. A shifted scan or a different print scale can make most of a sheet appear changed.
Where your comparison tool offers alignment controls, check the result at more than one unchanged location. If the files cannot be aligned reliably, record that limitation and use a manual review of the affected areas. Keep any transformed comparison copy separate from the source PDF.
Review changes in their drawing context
Inspect candidate differences at a readable zoom and return to the source sheets when a result is ambiguous. Review additions and deletions, revised dimensions, note changes, material schedules and references to other details. A moved element may affect a related sheet even when that second sheet has no visible difference.
Scanned documents require particular care. Search and text comparison depend on the quality of any recognised text. Check important values against the visible source, including decimal points, units and drawing identifiers. If a measurement is part of the review, calibrate against a known dimension for that sheet and confirm the units.
- Separate design changes from annotation, print and scan differences.
- Check changes outside the issuer’s revision clouds.
- Keep unclear findings open until the source or design owner resolves them.
Export a record the next reviewer can use
Give each material finding an identifier and record the old and new revisions, sheet location, observed change, reviewer and follow-up action. Use a short explanation alongside a cloud or highlight so the mark remains understandable without the original conversation.
Save a working version with editable annotations when further review is expected. If the recipient needs a flattened issue copy, keep it alongside the working file and unchanged source documents. Reopen the delivered PDF in the recipient’s expected viewer to check the page order and annotation visibility. Also check any exported findings list against the marked sheets.
In Preview, Apple documents Save and Export as options that preserve editable annotations, and Print followed by Save as PDF as a way to flatten them. Confirm the required deliverable format with the project’s document process.
Apple’s guidance on saving editable and flattened PDF annotations
Evaluate OpenBeam for the workflow
OpenBeam is Newport Resonance’s macOS tool for PDF markup, takeoff, revision comparison and conversion. Its public product page describes comparison with change clouds and overlay views, together with markup export to Excel or CSV. The current release is available through an early-access trial.
Use representative documents to evaluate fit: a clean drawing export, a scanned sheet and a package with added or removed pages. Check comparison readability, annotation preservation and the usefulness of the exported review record before adopting it for a project workflow.
View OpenBeam capabilities, system requirements and trial access
Before you close the review
- Unchanged source PDFs and their issue details are retained.
- Sheets are paired by identity, with additions and deletions recorded.
- Scale, rotation and alignment have been checked.
- Important differences have been verified against the visible source sheets.
- Findings include a location, explanation, owner and next action.
- The exported PDF and findings list have been reopened and checked.
OpenBeam for Mac
Explore PDF markup, calibrated takeoff, revision comparison and export in the OpenBeam early-access trial.