How to Check Logo Similarity During a Redesign Audit

Before you start

A logo similarity check is a review step, not a legal or mathematical proof. During a redesign audit, you compare a proposed mark with the current logo and, if needed, with other marks in the same product category. You can do this manually in an image editor or visual workspace. Some dedicated services offer automated similarity scoring, but do not assume a specific score exists in your tool unless the interface shows it. Check whether your image files are raster files such as PNG or vector files such as SVG. Keep the proposed redesign in the same format and approximate display size as the reference mark so differences in smoothing or sharpness do not look like real changes in shape.

Step-by-step instructions

These steps are ordered for a visual comparison in a browser-based image tool or a local design application. Adapt the names of controls to your software.

• 1. Open the current logo and the redesigned logo as separate layers.
• 2. Align both marks by their optical center, not the exact corner of the canvas.
• 3. Set both layers to the same height and preserve each mark as a separate movable layer.
• 4. Temporarily reduce the redesigned layer opacity to between 40 and 60 percent.
• 5. Move the redesigned layer over the current logo and compare the outer silhouette first.
• 6. Compare the internal negative space around the symbol and wordmark.
• 7. Restore the redesigned layer to full opacity and place the marks side by side.
• 8. Record the strongest shared features and the clearest differences in a short note.

If you are checking similarity across a larger set, repeat the comparison one pair at a time. Do not compare several marks at once, because the eye tends to blend details and produce a false sense of closeness. For a reversible check, keep the original files untouched and work only on copies or adjustment layers.

Check the output

Look at the comparison at a small size around 32 to 48 pixels high. If the marks still read as nearly the same shape at that size, their similarity is visually high. Then inspect a larger preview for differences in stroke weight, letter spacing, color, and detail. A useful result is a list of shared structural features and distinct visual differences. Do not treat a visual check as proof of trademark safety or uniqueness. Automated similarity tools may give a percentage, but the calculation method and reference library affect the meaning of that number.

Common problems and next steps

A common problem is comparing logos of different heights, which makes small shapes look more different than they are. Resize by height first and compare again. Another problem is checking only the color version; a logo can look similar in outline even when the palette differs. Convert both marks to grayscale or a solid silhouette and repeat the check.

If the redesigned mark keeps the same silhouette and changes only a small detail, consider whether the redesign is too close for its purpose. If the similarity check is part of a brand audit, document the comparison conditions: file type, approximate display size, background, and whether color or shape was prioritized. Use the check as one input for a design decision, not as the only gate.