Patent prior art is earlier information that may affect whether an invention is new or nonobvious enough for patent protection.
Prior art can include earlier patents, published applications, articles, products, public uses, sales, or other disclosures.
Why patent prior art matters
Patent rights depend on what was already known or available before the relevant filing date. Prior art can narrow claims, block patentability, or support an invalidity argument.
Understanding prior art helps explain why patent claims are written carefully and why patent searches matter.
Where patent prior art appears
Prior art appears in patent examination, patent applications, office actions, patent litigation, licensing due diligence, freedom-to-operate reviews, and invalidity defenses.
It is often compared to the claimed invention element by element.
How it differs from nearby terms
A patent is the legal right granted for an invention. Prior art is the earlier information used to test whether that right should exist or how broad it should be.
Patent licensing concerns permission to use patent rights, not whether the invention was patentable.
Practical example
An inventor claims a new device feature, but an earlier published patent application describes the same feature. That publication may be patent prior art.
Related Terms
Quick check
Question: Does prior art help test whether a patent claim is new or nonobvious?
Answer: Yes. Prior art is earlier information used in that analysis.