There isn't a set rule for the ideal number of blocks your maze should have.
However, keep in mind that, in unmoderated testing, testers' attention will significantly drop the longer the maze lasts.
Here are a few factors to keep in mind:
Setting the right expectations
At the start of a maze, it's important to be clear and transparent about all the relevant details.
This includes providing an estimate of the time it will take to complete the maze, as well as whether you will provide an incentive for participation.
To help with this, you can use the Welcome and Context screens to provide testers with the information to fully understand upfront what you expect from them.
Learn more about introducing your maze to testers
Incentives
If you're offering an incentive, the test can be longer.
Without an incentive, a high number of blocks is more likely to result in fatigue impacting the quality of the answers and the abandonment rate. If no incentive is involved, you may have better results if you keep the number of blocks under eight.
You can set up a URL redirect in the Thank You screen to reward testers who completed your maze. For example, you can direct them to an incentives platform where they can claim a reward or use a custom discount code.
Learn more about setting up redirects at the end of a test
Maze panel
If using the Maze panel, you should be especially mindful of the length of your tasks. Make sure you're not asking participants to do too much given the compensation they'll receive.
An unreasonably time-consuming maze may cause testers to feel underpaid and abandon the test, causing your order to go unfulfilled.
Pay attention to blocks that can be particularly time-consuming, such as prototype/website tests, or card sorts.