On 20 January, Google announced that it will discontinue Google Optimize.
Google Optimize is a tool where you could easily perform A/B tests on your website. It has been a well-used tool for us at Contitude as we have been able to easily test improvement opportunities on websites.
Until 30 September, Google Optimize will continue to collect data, but after that you will no longer be able to use the tool.

Is there an alternative to Google Optimize?
Google's own plan is to create A/B testing capabilities in Google Analytics 4 (GA4).
They have not gone out with exactly when these features will be launched and how they will work and look but most likely some sort of version will come before September 30.
Otherwise, there are many other tools for setting up A/B tests. Here is a small list of alternative tools:
AB Tasty
Adobe Target
Convert
Kameleoon
Maxymizer
Monetate
Omniconvert
Optimizely
VWO
Webtrends Optimize
Why is Google discontinuing Google Optimize?
According to the news published by Google about the discontinuation of Google Optimize, the primary reason is that the functionality sought after by A/B testers is not available in Google Optimize. Therefore they think it is better to invest in a new version of A/B testing in GA4 instead.
I disagree with Google themselves there but think that Google Optimize filled a great function with a free tool for simple and easy A/B testing. The alternatives that are free are not as good as Google Optimize in my opinion.
Here you can find the full message from Google.
Google Optimize Sunset