What are some great free websites for searching patents by keywords, class code or patent owner?

Here at Ambercite we develop tools based on citation searching. We believe the right combination of our large database of patents and their citations – and our unique analytics tools can quickly find you similar patents to relevant patents that you already know about.

However in some cases you may not know what the best starting patents are. You may have some concepts, keywords or potential patent owners you are interested, but little more than that. So what can you do?

The answer to this question is a conventional patent search. There are a number of subscription and free databases out there that you can use for this. I don’t think that paid subscription engines need any promotion from us, but I am happy to recommend the following free patent search engines

 1)  Google Patent If you can use Google, you can use Google Patent – and I know that professional searchers and even patent examiners the world over use Google Patent. What not everybody know is that, besides its simple default box shown below:


There is also an advanced search capability, but you firstly need to run a simple search, and then the advanced search becomes an option. Or you can open this link here



That is the good news. What is not so good that is Google, confusingly, provide two different versions of Google patent – with the second version found here. The second version has some benefits, but overall I prefer the first version. Maybe Google will merge these two versions in the future.


2) “The Lens”. This term is awkward to seach for, but if you use their earlier name “Patent Lens” this will be easy to find.   

When first opened up, it looks like this, with a very simple search interfact



But you select the grey ‘settings’ box to the right, it opens up what is a quite a useful search interface, as shown below. And this includes a greater range of search fields than just ‘Full Text” or “Inventors”


Once you have a set of results, you are provided with a further set of filters and display options, including the ability to sort the results by a number of fields including citation count.


These are my two main ‘goto’ free search engines. In addition, I can list:


Why would Ambercite promote free competitors to our own subscription products?

The answer is – because they are not true competitors. They are instead very useful sources of free keyword, class code or perhaps owner searching – and can help find starting patents for our tools. None of them offer our rapid and productive ability to rapidly find similar patents to a known list of starting patents and so greatly extend the list – or the ability to find patents that fall outside of your list of starting assumptions. This is why our users are so happy with our product.

So in other words, Ambercite offer additional and valuable capability over and above all of these free products – that is well worth the reasonable cost of a subscription.

Would you like to see this for yourself? Please contact us to ask about a demonstration and free trial.


Do you have your own free search engine that you think is better than the one mentioned above?

Come back to us if you do – I would be happy to check them out, and add these to the list if I like them.

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