When two things look alike

Two products on a screen look strikingly similar. You feel certain one came from the other, or you worry that your own work is too close to something you have just discovered. Slow the comparison down. The law never asks one universal question called "How alike are they?" Copyright, trademark and patent law each protect something different, so split the comparison by right before you decide anything.

Start with the part you are comparing

A café menu holds photographs, written descriptions, a logo, prices and ordinary names for dishes. A match in the photographs is a different matter from a match in the price list or the idea of a lunch special. U.S. copyright protects original expression; it does not protect facts, ideas, systems or methods of operation, and it does not protect names, titles, slogans or short phrases 1. Compare whole pages without separating those elements and the evidence looks stronger or weaker than it really is.

Two guides that explain the same gardening technique will share facts and practical steps. A copied drawing or passage is a different concern from a shared subject. The same split helps if you are the one accused: ask what protected expression you are said to have taken, not whether both works belong to the same genre.

Build the comparison element by element:

1. Put each matching feature on its own line: a photograph, a paragraph, a logo, a product name, the way a device works.
2. Next to each, name the right that could cover it. Expression points to copyright. Facts, ideas and methods are outside copyright. Names, titles and slogans are trademark questions, not copyright ones 1. How a product works points to a patent.
3. For each copyright line, write what the other side did with it: copied it, adapted it, distributed copies, or displayed or performed it publicly. Those are the copyright owner's exclusive rights 9.
4. Check whether the work is registered: search the Copyright Office's Copyright Public Records System, which covers 1898–1945 and 1978 to the present 8.
5. Keep the full pages, dates and surroundings, not just cropped pieces. Saving evidence while the facts are still available shows how.

A brand comparison is about meaning in the market

To win a U.S. trademark infringement claim, the owner must show a valid mark, priority (their rights are older, or "senior"), and that the other use is likely to confuse consumers about source or sponsorship 2. Courts weigh how similar the marks are, how closely the goods or services are related, any evidence of actual confusion, the other side's intent and the strength of the mark 2. Identical spelling is not required, and a registration does not cover a word in every setting: how related the goods or services are is one of the key factors.

So preserve the setting, not two cropped logos:

• What each business sells and where customers meet it.
• Whether the use suggests a connection or sponsorship.
• How the name is used: as the seller's own brand, or to refer to someone else's product in a review or comparison. The question stays the same: are customers likely to be confused about who is behind the product 2?
• Any message from a customer who mixed the two up. Actual confusion is one of the key factors 2.

Then look the mark up in the USPTO's Trademark Search system 7. A federal registration on the Principal Register gives its owner a legal presumption that the mark is valid and theirs, which the other side can rebut in court 2.

A patent comparison reads the claims

For a U.S. patent, infringement analysis primarily compares the language of the patent claims with the accused product or process 3. The claims define the invention and come at the end of the specification 5; the drawings on the front page do not define it. Two products can look alike and work differently, or look different and still fall within the same claim.

1. Find the patent in USPTO Patent Public Search and read its claims 6. From November 7, 2026, the search requires signing in with a USPTO.gov account 6.
2. Check that the patent is still in force. A utility patent expires if its maintenance fees, due 3½, 7½ and 11½ years after grant, go unpaid through the grace period; after a patent expires, anyone may make, use or sell the invention unless another unexpired patent covers it 3.
3. Know who decides. The USPTO has no jurisdiction over infringement questions; the patent owner sues in federal court, which makes the final decision, and the accused side commonly argues the patent is invalid 3.

A visual comparison made by a general AI is not a patent opinion. Before you accuse anyone of patent infringement or answer an accusation, have a patent litigation attorney read the claims against the product.

Product shapes and confidential know-how follow their own rules: see When the shape of a product matters and Keeping valuable know-how a secret.

Permission and exceptions belong in the comparison

Using protected material can still be lawful. Look for a license, permission from someone who holds the right, or a legal exception: the copyright owner's exclusive rights are subject to the exceptions in sections 107 to 122 of the Copyright Act 9. U.S. fair use weighs four factors: the purpose and character of the use, the nature of the copyrighted work, the amount and importance of the portion used, and the effect on the market for the original 4. Courts decide case by case, and no percentage or number of words is automatically safe 4. Changing a few details or adding a credit does not answer those four questions.

Finish your comparison with three lines: the matching features, the right you believe covers each one, and the permission or exception that could apply. You end with either a clearer concern or a sharper question for a professional. Both are progress beyond "these look the same." Then decide what you want to happen: What would a good resolution look like.