The choice between a patent and a trade secret is a choice between two incompatible ways of paying for exclusivity. A patent buys you a 20-year right to exclude everyone, including independent inventors, and the price is telling the world exactly how your invention works. A trade secret costs no disclosure and can last indefinitely, but it protects only against people who take the information improperly. Anyone who figures it out honestly owes you nothing.
That asymmetry, not term length and not filing cost, decides most real cases. The useful question is never “which is stronger.” It is whether your advantage can be seen in the thing you sell.
A patent under 35 U.S.C. § 154 confers the right to exclude others from making, using, offering to sell, or selling the claimed invention for 20 years from the earliest non-provisional filing date. Infringement is a strict-liability matter. A competitor who never heard of you, never saw your product, and developed the same thing in a clean room is still liable.
A trade secret has no registration and no term. Under the Defend Trade Secrets Act, 18 U.S.C. § 1839(3), information qualifies if the owner takes reasonable measures to keep it secret and it derives independent economic value from not being generally known or readily ascertainable. Protection lasts exactly as long as those two conditions hold and evaporates the moment they do not. Liability attaches only to misappropriation, which means acquisition by improper means or breach of a duty of confidence.
Coca-Cola is the canonical illustration of the upside. The formula has been a trade secret since 1886. A patent filed then would have expired before the First World War and put the formula in the public domain forever.
Section 1839(6)(B) of the DTSA says the plain text out loud: improper means “does not include reverse engineering, independent derivation, or any other lawful means of acquisition.” The Uniform Trade Secrets Act, adopted in some form by nearly every state, says the same thing in its commentary. The Supreme Court blessed the principle in Kewanee Oil Co. v. Bicron Corp., 416 U.S. 470 (1974), holding that trade secret law coexists with the patent system precisely because it is the weaker right and does not remove anything from the public domain.
So run the test in this order:
Manufacturing know-how, process parameters, customer data, and negative know-how, meaning the expensive knowledge of what does not work, all cluster on the secret side. Products, formulations, and anything a teardown reveals cluster on the patent side.
People underrate how badly a failed application can go. Under 35 U.S.C. § 122(b), applications publish 18 months after the earliest priority date. Publication is not conditioned on allowance. If your application is rejected, or you abandon it after an unfavorable office action, the disclosure has already happened and the secret is gone with nothing received in return.
There is a nonpublication request available, but only if you certify that the invention will not be the subject of an application filed abroad. That is a real forfeiture for anything with an international market.
Section 112 compounds it. The specification must enable a person of ordinary skill to make and use the invention, and post-AIA law still requires disclosing the best mode known to the inventor even though failure to do so is no longer a ground for invalidity or unenforceability in litigation. You cannot file a hollow application that patents the concept while hiding the part that makes it work.
A trap that catches sophisticated companies: secretly using your process commercially can start the clock against your own later patent application. Judge Learned Hand’s decision in Metallizing Engineering Co. v. Kenyon Bearing & Auto Parts Co., 153 F.2d 516 (2d Cir. 1946), held that an inventor who commercially exploits a secret process forfeits the right to patent it after the statutory period, on the theory that you may not extend your monopoly by keeping it quiet first and patenting later.
The Supreme Court confirmed the modern statute follows the same logic in Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA, Inc., 586 U.S. 123 (2019), holding that a sale to a third party bound by confidentiality still triggers the § 102 on-sale bar. The AIA’s phrase “otherwise available to the public” did not repeal decades of precedent. Practical consequence: trade secret first, patent later is not a strategy you can run indefinitely.
Because independent invention is no defense to infringement, the trade secret holder faces a nightmare: a rival independently invents the same process, patents it, and sues the company that has been quietly using it for a decade.
The AIA answered this with the prior commercial use defense in 35 U.S.C. § 273. If you commercially used the subject matter in the United States in good faith at least one year before the earlier of two dates, the patent’s effective filing date or the inventor’s qualifying public disclosure under § 102(b), you have a defense to infringement. It is narrow and worth reading closely: it is personal to you, not a license, it is not transferable except with the business, it does not invalidate the patent, and asserting it without a reasonable basis triggers fee shifting. It is a shield that lets you keep doing what you were doing. It is not a shield that lets you grow.
Sophisticated portfolios rarely choose once. They partition:
For the step-by-step version of this decision applied to a specific invention, see the guide below.
What is the difference between a trade secret and a patent? A patent is a limited monopoly the government grants in exchange for publishing the invention in full. It lasts 20 years from filing and is enforceable against everyone, including someone who invented the same thing independently. A trade secret is not granted by anyone. It exists as long as the information stays secret and gives you a competitive advantage, so it can last forever, but it protects only against acquisition by improper means.
Can reverse engineering defeat a trade secret? Yes, and this is the decisive asymmetry. Reverse engineering a lawfully obtained product is not misappropriation under the Defend Trade Secrets Act or the Uniform Trade Secrets Act, and independent development is equally lawful. Neither is a defense to patent infringement. If your advantage is visible in the product you ship, a trade secret is protecting almost nothing.
Does filing a patent application destroy a trade secret? Usually. U.S. applications publish 18 months after the earliest priority date whether or not the patent ever issues, so an application that is abandoned or rejected still hands the disclosed method to the public. Nonpublication requests are available only if you forgo foreign filing, and the specification must enable the invention regardless.
Can I use both a patent and a trade secret? Often, on different subject matter. The common hybrid patents what a competitor could detect or reverse engineer, such as a device or a claimed composition, and keeps as a secret the manufacturing parameters and know-how that never leave the plant. What you cannot do is keep the best mode of a claimed invention out of the application and expect the claim to survive Section 112 scrutiny.
Going further: Patent vs. trade secret, a decision walkthrough .
This page is general legal information, not legal advice, and it does not create an attorney-client relationship.
The Federal Circuit voided reissue handguard claims for lack of written description while finding a trade secret could cover what the patent never disclosed.
Judge Posner upholds the loss of a trade-secret verdict, explaining that a process published in a patent application ordinarily loses secrecy and that BondPro showed no measurable value.
The Supreme Court scrapped the decades-old 'substantial competitive harm' test and held that commercial data is confidential under FOIA Exemption 4 when it is kept private and shared with the government in confidence.
A half-century after the Supreme Court blessed trade secrets, Kewanee Oil v. Bicron remains the clearest map of when to file and when to keep quiet.
When Stiffel's lamp patents were held invalid, the Supreme Court ruled that no state unfair-competition law could stop Sears from copying the unpatented design, establishing that exclusivity flows only from the federal patent bargain.
Judge Learned Hand held that an inventor who commercially exploits an invention in secret beyond the grace period forfeits the right to patent it, forcing a choice between trade-secret protection and the patent monopoly.
A unanimous Supreme Court struck down Florida's anti-plug-molding statute, holding that a state may not grant patent-like protection to an unpatented design already disclosed to the public, and explaining why trade-secret law survives the same test.
The Supreme Court held that federal patent law does not bar a state-law contract requiring perpetual royalties on a keyholder design whose patent application was rejected, a foundational endorsement of the license-instead-of-patent strategy.
