Espacenet

Espacenet is one of the world's largest free patent databases, maintained by the European Patent Office and providing access to over 140 million patent documents from across the globe. What makes Espacenet particularly valuable is its comprehensive coverage — it includes patent data from nearly every patent office worldwide, along with machine translations of documents that would otherwise be inaccessible due to language barriers. The platform offers multiple search interfaces, from a simple smart search that works like a regular search engine to advanced tools for experienced patent professionals. One of its most powerful features is the Common Citation Document, which lets you see how different patent offices have evaluated the same invention. For anyone involved in innovation, intellectual property research, or technology scouting, Espacenet provides free access to a wealth of patent information that would otherwise require expensive commercial subscriptions.