I have learned to look at 2 sites. One is Mobilize and the other is Indivisible. The Indivisible site usually stops posting their numbers when they hit 1,000 so I get out my trusty calculator and add the numbers myself. I keep track of this stuff, old school. I find this is fairly accurate since the MSM never mentions protests until AFTER they have taken place and even then they grossly under report the actual numbers.
The NO KINGS protest in San Diego had two marches converge into one location and I was standing on an elevated area and I saw the sea of people and I have never seen anything like it before. 80,000 protesters flowing into one area!!!!! I was so proud of my city. A week before this protest an ICE team went into a local restaurant and arrested everyone. This was the first time it happened in San Diego. The residents in the area came out to tell ICE to "get the fuck out" of their neighborhood and it was a big deal for San Diego. That definitely increased the anger and drove locals to protest.