Free drawing comparison for construction
A new revision.
A different job?
A moved wall. A revised level. A detail that changes the work. Upload the earlier and the new revision of one sheet and see every change pinned on the drawing, with what it is likely to affect.
Compare two revisionsFree. No sign-up needed. For whole drawing sets, a change register and RFIs raised from the changes, use PlanOps.
The internal wall shifts into the adjoining room.
Does the revised layout affect setting out or the room fit-out?
Free tool
Compare two revisions
One sheet, two issues. PDF, PNG or JPEG, single page each. The drawing number is read from both first, so two different drawings are refused rather than compared.
Getting ready…
This is an automated comparison of two single sheets by software. It finds what looks different and says where; it has no sight of the rest of the drawing set, the specification or the work on site, and it is not a substitute for a check by the person responsible for the drawing.
Find the change. Understand the consequence.
From drawing to decision
The useful bit is
what happens next.
A revision letter tells you the drawing has changed. Your team needs to know what that means for the work.
- 01
Upload the two revisions.
The earlier issue and the one that has just arrived. Both must be the same drawing: the number and revision are read from each title block first and two different sheets are refused before the comparison starts.
- 02
Look at what changed.
Each change is pinned on the new revision and described in plain words - what moved, where and whether it is one to check before you build. Flick between side by side, a wipe and an overlay to see it for yourself.
- 03
Decide what it means for the job.
Check the findings against the issued drawings. Does the change affect setting out, materials or work already planned? Your team makes the call and PlanOps can carry the changes into a register and raise the RFIs.
The bigger job
Comparing the sheet is
one step out of six.
A revision does not start as two files on a desk and it does not end with a list of changes. Here is the whole run on a PlanOps project, with the part this page does marked.
- 01
The revision arrives
A new issue lands from the designer. The drawing number and revision are read from the sheet and it is filed against the drawing it revises, so the set always knows which issue is current.
- 02
It is compared with the one beforeYou are here
Every revision is compared with the previous issue as it arrives, and any two revisions of a drawing can be compared on request - P04 against P06, say - not only the latest pair.
This page does this one step, for one sheet. It compares the two revisions you give it and keeps nothing afterwards.
- 03
Each change becomes a record
Every difference found is written to the project as a change: what moved, where on the sheet in words, how much it matters and whether it is likely to cost something. Re-running a comparison refreshes a change rather than duplicating it.
- 04
Someone decides what to do about it
From the change itself: mark it seen, ask the engineer by raising an RFI, give it to someone as a task, or flag it to commercial. The RFI or task stays linked to the change that caused it.
- 05
It is tied to the work it affects
A change carries the packages its drawing is linked to, so the subcontractor whose RAMS and programme rest on that sheet can be told. Where the project assesses quantities, the quantity changes are recorded as well.
- 06
It stays on the record
A drawing change register - by issue or by package - is generated, versioned, printed and exported like any other project register, with the issue named by its sheets, sender and date and a count of what is still open.
On this page
- One sheet, two revisions, uploaded by hand
- Single-page files only; drawing numbers checked first, so a mismatched pair is refused
- Findings pinned on the sheet, with a plain description of each
- A private link that expires, then the images and findings are deleted
- No drawing set, no register, nothing linked to the work
On a PlanOps project
- Every revision compared with the one before as it arrives, and any two on request
- Each change kept as a record with a state, an owner and a history
- RFIs and tasks raised from the change and linked back to it
- Changes carried to the packages the drawing is linked to
- A drawing change register by issue or package, printed and exported
- The rest of the project alongside - RAMS, RFIs, programme and documents
Beyond one sheet
Your drawings already
have a home in PlanOps.
Whole drawing sets, a change register that keeps every finding with its drawing and RFIs raised from the changes - alongside the rest of the project.
Data handling
What happens to your drawings.
What we keep, what we delete and when.
- Your files are not kept
- Your two files are used to make one image of each sheet and are not saved. The images are kept while your result link works.
- The result and its page images expire
- Your result link works for a limited time. When it expires, the page images and the findings are deleted together, automatically. Your result page shows when its private link expires.
- Only revisions of the same drawing are compared
- The drawing number and revision are read from each sheet first. Two different drawings are refused and nothing is compared; if a number cannot be read, the result says so and marks the drawing number as not confirmed.
- No account, no sales call
- You do not need an account to compare two drawings. An email address is optional: give one and we will send your result link, leave it out and the link stays in your browser.
A few useful details.
What is drawing comparison?
Drawing comparison reviews two revisions of a construction drawing to identify differences in geometry, dimensions, notes or details. It helps a project team understand what needs checking when a revised drawing arrives.
What can I upload?
Two single-page files - PDF, PNG or JPEG - that are revisions of the same drawing. Multi-page PDFs are refused: export the one sheet you want compared. A PDF with a text layer gives the best result because the drawing number and revision can be read from it before the comparison starts.
How do you know the two files are the same drawing?
The drawing number is read from each sheet's text layer first. If both are readable and differ, the pair is refused and nothing is compared. If a number cannot be read, the comparison goes ahead and the title blocks are read during it; if the title blocks disagree, the changes aren't shown, and if a title block can't be read, the result says the drawing number is not confirmed so you know to check it yourself.
Are my drawings stored?
The uploaded files are not. We make one image of each sheet, keep those images only for as long as your private result link works so the findings can be drawn on them and then delete the images and the result together.
Does AI replace the drawing review?
No. The findings are a starting point for review. Check them against the issued drawings and use the appropriate designer or engineer to resolve anything unclear before work proceeds.
What does PlanOps add?
Whole drawing sets rather than one sheet, a change register that keeps every finding with its drawing, RFIs raised from the changes and the rest of the project's documents, programme and quality records alongside. The free tool is one sheet at a time.