KordFree diff tool
Compare two Visio files
Diff two Visio diagrams in your browser, free, no account: see what changed between two .vsdx revisions of a P&ID or process diagram without opening Visio. Built by Kord; opens with a sample P&ID pair loaded.
Free, no account. Opens with a two-revision feed P&ID drawn in Visio loaded.
Plenty of real P&IDs and process diagrams are drawn in Visio - not the CAD department's, but the ones process engineers actually iterate on. Visio itself has no usable way to compare two saved .vsdx files, and the usual workaround is exporting both to PDF and comparing those, which works right up until nobody does it.
Drop the two .vsdx revisions here and see them against each other in the browser - no Visio license on the machine required. It opens with a sample feed-section P&ID at two revisions, which is a fair preview of what your own diagrams will look like.
What the comparison shows
What you get on screen once both files are in, and why each piece is there:
- The diagram, rendered. Both revisions drawn and compared as diagrams - shapes, connectors, and labels - not as two XML trees.
- No Visio required. The reviewer with a Mac and no Office plan sees the same comparison you do.
- A link, not an export. Share the comparison directly instead of exporting two PDFs and mailing both.
How to compare two Visio diagrams
Three steps, none of which is signing up:
- Open the diff tool - it loads with a two-revision feed P&ID drawn in Visio already compared, so you see the result shape before committing your own files.
- Drop your two Visio diagrams into the Before and After slots - up to 25 MB each.
- Read the comparison. If someone else needs to see it, Share turns it into a link.
FAQ
The questions people ask before dropping real files on a free tool, answered plainly:
Is it free?
Yes. No account, no trial clock, no watermark. The tool exists because we build Kord, version control for engineering document sets, and a diff you can run in ten seconds explains the product faster than any brochure.
Do my diagrams get stored?
Files are kept only as long as it takes to draw the comparison. Most formats render in your browser; Word and PowerPoint are converted to a preview by our servers in memory, and a file too big to ride a request travels through a short-lived upload that is deleted automatically. There is no account, so there is no history to attach anything to. The longer answer is at work.withkord.com/security.
Why is there no compare inside Visio?
Visio once shipped a Compare Drawings feature; current Visio does not expose a usable one for .vsdx revisions. Most teams fall back to exporting PDFs. Diffing the .vsdx directly skips the export step and the discipline it depends on.
Our P&IDs live next to datasheets and calcs. Can the whole set be tracked?
That is Kord: version control on the document set, this same visual diff between revisions of each file, review sessions with sign-off, and an AI check that flags when the P&ID and the line list disagree.
When two files aren't the real problem
A one-off diff answers a one-off question. If your team compares Visio diagrams every revision cycle - and the revision that matters sits next to drawings, specs, and calc sheets that have to agree with it - that is the job Kord exists for: version control on the whole document set, this same visual comparison between any two revisions, and review sessions with sign-off before anything is issued. The longer argument is in Git for documents.
Compare other formats
The same tool reads eleven formats - the full list is on the compare index. Nearby: Compare two PDF files · Compare two SVG files · Compare two DXF files.