PCB revision comparison
Compare schematic netlists, PDF drawings, BOMs, Gerbers, drill files, pick-and-place data, ODB++ and IPC-2581 exports between PCB revisions—without uploading your project to a hosted comparison service.
Runs locally · Seven comparison types · Runs on Windows · Review-ready exports
Interface illustration based on the Kontr-Owl comparison workflow.
Revision control
Replacing an unavailable part, correcting a footprint or refining the layout can change multiple design and manufacturing files. Kontr-Owl helps you verify that the final revision contains the changes you intended—and no surprises.
A substitution or layout adjustment may affect more than the file you were editing.
Compare the previous version with the revised version and create a clear record of what changed and what remained identical.
Project coverage
Check the principal design, manufacturing and product-exchange files produced for a PCB revision.
Compare connectivity between revisions—nets, pins, components, footprints and values—and flag nets that lost their expected connections.
Identify added, removed and modified component records using a designator or reference column.
Inspect complete ODB++ products and IPC-2581 exports for manifest, stackup, component, netlist, drill, outline and layer-count changes.
Compare copper, mask, paste, silkscreen and supported mechanical layers using a visual overlay. Layers are paired automatically by content, so renamed or extensionless board-house files still line up.
Review hole additions, removals, movement, size changes and plating changes across Excellon drill spans.
Compare component population, position, rotation, value, footprint and board side using configurable tolerances.
Compare any drawing pair page by page—schematic prints, fabrication or assembly drawings—and highlight the regions that differ.
Combine selected comparison records into one PDF, HTML or CSV summary for review and project documentation.
Real-world file support
Kontr-Owl supports standard output from Altium Designer, KiCad, OrCAD/Allegro, EAGLE, Fusion 360, EasyEDA, DipTrace, PADS and other tools that produce the underlying supported formats.
Gerber, drill, pick-and-place, ODB++ and IPC-2581 inputs are not rejected solely because a board house used an unusual or missing extension.
Gerber layers are paired by comparing the images themselves, not the filenames, and a shifted or mirrored board-house set is aligned automatically.
Units are normalised to millimetres. Text parsers tolerate common line endings and byte-order marks, while pick-and-place columns, delimiters and units are detected automatically.
If a file cannot be parsed, the tool reports the reason instead of silently producing an empty or misleading comparison.
| Comparison | Accepted input | Typical sources | Files per revision | What is compared |
|---|---|---|---|---|
| Schematics | KiCad netlist Altium Wire List Protel .NET EAGLE netlist pin-list CSV | Altium, KiCad, EAGLE and generic exported pin lists | One file | Nets, pins, components, footprints, values and connectivity regressions. |
| Bill of Materials | .csv .xlsx .xls | Altium, KiCad and generic spreadsheet exports | One file | Added, removed, changed and unchanged component records. |
| PCB Data | .tgz .tar.gz .zip unpacked folder IPC-2581 .xml any extension | Altium and other ODB++ or IPC-2581 capable PCB tools | One product | Manifest, metadata, stackup, components, nets, drill spans, board outline and feature counts. |
| Gerber | RS-274X any extension extensionless | Altium, KiCad, EAGLE, Fusion 360, OrCAD/Allegro and board-house outputs | Multiple layers | Rasterised visual differences across paired Gerber layers. |
| Drill | Excellon .txt .tx1 .drl .drd any extension | Altium, KiCad, EAGLE, Fusion 360, EasyEDA, DipTrace and PADS | Multiple spans | Hole additions, removals, movement, resizing, slots and plating. |
| Pick & Place | .csv .txt .pos .mnt .mnb delimited text | Altium, KiCad, EAGLE, Fusion 360, OrCAD/Allegro, EasyEDA, DipTrace and PADS | One file | Population, movement, rotation, side, value and footprint changes. |
| Any CAD tool or PDF producer | One PDF | Pages paired by index, visual changes and changed regions. |
File extensions shown above are common examples, not always strict requirements. Gerber, drill, pick-and-place, ODB++ and IPC-2581 parsers inspect content because manufacturing files are frequently renamed or supplied without a conventional extension.
.SchDoc,
.kicad_sch and .dsn should be printed to PDF
and compared on the PDF tab. BOM text or TSV files should be converted
to CSV or XLSX. Unsupported netlists such as EDIF, Telesis, PADS ASCII
or SPICE should be exported as a KiCad netlist, Protel
.NET or a pin-list CSV.
Comparison reports
Build a consolidated PDF, HTML or CSV summary from selected comparisons, including identified changes and verified-identical results.
How it works
A focused workflow for checking a personal PCB project or reviewing a complete manufacturing release.
Load the previous version and the revised version of the files you want to compare.
Choose the relevant page, Gerber layer, drill span, ODB++ or IPC-2581 step, or structured file pair.
Inspect visual overlays, changed regions and structured summaries using appropriate tolerances.
Save comparison outputs and optionally combine selected results into a consolidated report.
Product demonstration
Watch how Kontr-Owl loads two PCB revisions, identifies differences and produces a reviewable output.
Open on YouTubeProduct principles
PCB project files are processed on the machine running Kontr-Owl, not uploaded to a hosted comparison service.
Kontr-Owl runs locally on Windows. Linux and macOS are not supported yet.
Cyan and magenta distinguish old and new content without relying on the conventional red-and-green pairing.
Export visual comparisons and structured summaries for build notes, project documentation or formal review.
Early access
Request access for a personal project, open-source design, university project or professional engineering workflow.
Available for Windows
Privacy and responsible use
The access form collects only the information needed to understand your request, assess compatibility and contact you about Kontr-Owl.
Last updated: 25 August 2026
When you request access, the form asks for your name, email address, user type and primary PCB design tool. If you contact Kontr-Owl directly, the contents of your message and any information you choose to provide will also be received.
Your information is used only for administering your request, communicating with you about Kontr-Owl and providing support you request. It is not sold, rented or shared with data brokers, and it is not used for unrelated advertising or marketing campaigns.
The Kontr-Owl application performs comparisons locally on the machine where it is running. PCB design and manufacturing files loaded into the application are not sent to this landing page or uploaded to Kontr-Owl during the normal comparison workflow.
If you voluntarily send example files for troubleshooting, they will be used only to investigate the issue for which they were provided. Do not send confidential files unless authorised.
The access form is processed by Formspree, which receives the submitted form data to deliver your request. The demonstration uses YouTube's privacy-enhanced domain. External services are also governed by their own privacy policies.
Incomplete requests, requests that cannot be progressed and requests where no access relationship is established will be deleted no later than 12 months after the most recent relevant communication.
If access is provided, the minimum records reasonably needed to administer that access may be retained while the relationship is active and for any period required for security, dispute resolution or legal obligations.
You may ask what personal information is held about you, request a correction or request deletion, subject to any information that must be retained for legal or security reasons. Contact kontrowl.tool@gmail.com.
Last updated: 25 August 2026
Kontr-Owl is a comparison and review-assistance tool. It helps users identify differences between PCB revisions and create review records. It does not design a PCB, perform complete electrical or manufacturing verification, or certify a design as correct or ready for production.
A clean or “identical” result means that no difference was detected by the selected comparison using the supplied files, settings, tolerances and supported parser behaviour. It does not prove that the design is correct, safe, manufacturable or compliant.
Kontr-Owl must not be treated as the person or authority signing off a fabrication release, tapeout or production order. The user remains responsible for the final engineering decision.
Support applies to the documented formats and parser behaviour of the installed version. Real CAD exports may contain malformed, proprietary, ambiguous or previously unseen constructs. A file extension alone does not guarantee compatibility.
Visual results can be affected by resolution, coordinate precision, page order, file pairing and tolerances. Structured comparisons depend on the quality and meaning of supplied fields.
To the maximum extent permitted by law, Kontr-Owl is provided “as is” and “as available”, without warranties that it will detect every change, operate without interruption or suit a particular project, production process or regulatory requirement.
To the maximum extent permitted by law, the developer is not responsible for fabrication losses, component losses, redesign costs, production delays, lost data, lost profits or other indirect or consequential loss arising from reliance on the tool or outputs.
Nothing in these terms excludes responsibility that cannot lawfully be excluded or limited.
Use Kontr-Owl lawfully and only with files you are authorised to access and process. Do not distribute malware, interfere with systems, violate another party’s rights or process unlawfully obtained confidential information.
Kontr-Owl uses third-party libraries and may call independently installed tools such as gerbv. Those components remain subject to their own licences and terms.
These terms and the supported-format list may be updated as the software changes. Review the terms supplied with the version you use before relying on it for production. Questions: kontrowl.tool@gmail.com.