6 free patent search tools you can use right now
In a series of blog posts, Marco Coolen provides insight into his work as a Dutch and European patent attorney at AOMB.
Published on November 9, 2025
Marco, a patent attorney at AOMB since 2013, shares his expertise on IO+ about patents—how they work, why they matter, and when they lose their value.
Before you develop a new machine, build a smart algorithm, or enter an international market, you want to be sure of one thing: does this already exist?
Patent research is your first port of call. It prevents you from reinventing the wheel or, worse still, from unintentionally infringing on someone else's rights.
The good news is that you don't need to purchase expensive software or licenses. There are excellent free tools that can take you surprisingly far.
And the best part? You can start using them today, without a business case or approval rounds.
Marco Coolen, photo © Bart van Overbeeke
1. Espacenet – the European leader
My personal favorite. Espacenet is the European search engine for patents and offers free access to over 150 million patent publications worldwide.
What makes Espacenet so great?
- Translation function (useful if you come across Japanese or Chinese patents).
- Smart filters to quickly work through large search results.
- Easy search by keywords, numbers, or classifications.
If you want to search seriously, this is your first stop.
2. Google Patents – simple but surprising
Google Patents searches the way you are used to with Google: fast, broad, and accessible.
- Don't expect in-depth analysis.
- But you will find surprising discoveries if you search creatively.
- Especially useful for gathering ideas and exploring existing solutions in the early stages.
3. WIPO Patentscope – global overview
WIPO (World Intellectual Property Organization) offers a broad overview of international patent applications.
- Not limited to one region.
- Useful if you are or want to become internationally active.
- Also provides access to PCT applications (international provisional applications).
4. USPTO Patent Public Search – focus on America
If you are looking towards the United States, this is a must.
- Very detailed.
- Perfect for looking up specific American patent applications.
- Definitely useful if you already have a patent number.
5. EPO Deep Tech Finder – for the strategists among us
This tool combines patent data with financing information from deep tech startups.
- Ideal if you want to know which young companies are active in your field.
- Perfect for competition and investment analysis.
- A relatively unknown but very valuable tool.
6. AI tools such as ChatGPT and Perplexity – smart assistants
Don't let these tools search patents independently just yet – they still lack accuracy and complete coverage.
But they are excellent at:
- Search assistance: which terms and variants can you use?
- Summarizing found patents (after copying the text).
- Refreshing your search strategy.
Think of AI as your digital assistant that helps you search better in the real patent databases.
Six free tools, countless valuable insights
You don't need an expensive subscription to get started with serious patent research. With these free tools, you can do a lot of the groundwork yourself.
Do you want to dig really deep? Then it is still wise to engage a Qualified Patent Information Professional or your patent attorney. They will help you to interpret search results correctly and identify hidden risks in good time.
But: you can start for yourself today. And it won't cost you anything. Just a little curiosity.
The World of Patents
Every Sunday, Marco Coolen shares his insights from the world of patents. Read the entire series here.