There are so many better beaches than this one. Topanga Beach is just OK. The beach is clean and the lifeguards are responsive and present. But that is the only thing that I like about this beach. The reason I didn't like this beach is that there is a steep incline where the water meets the beach. The slope is upwards. That means when a small child is playing in the waves, as the wave goes back out to sea, the child is pulled in a downward incline. My daughter fell many times, and not only did the water pull her legs out from under her, because of the incline, but when she caught herself with her hands, she also lost her balance and would fall on her face. We have been to enough level beaches to know that she does not loose her balance from just the waves. And if she does loose her balance she does not fall forward on to her face, but down on her butt. This was all about the incline. That being said, we did have a fun time in the sand.
The parking is steep as it is with all beach parking. It's $9, if you are lucky enough to find parking on Topanga, then parking is free! You might have to walk a bit though.
There are restrooms and showers which is very nice. The restrooms are super clean.
So if you have older children or if it's just adults it is a good beach to come to. It wasn't as busy as some of the other beaches and the restrooms are clean and convenient. If your children are toddlers, then skip this beach and hit Santa Monica beach instead.