How do you find number of people using a SaaS app?

Public companies (like Twilio) share this information with you ✨

Other companies sometimes volunteer their metrics here on Indie Hackers or Baremetrics. Companies also sometimes mention metrics in announcement posts: "Big day, everyone! We hit 1000 customers 🎉!"

Here's an imperfect proxy: Count app store or package (like npm) installs. You could also skim social media follower counts, search rankings, and press to get an idea about a service's popularity.

If all else fails, you can ask someone at the company or even survey the public.

My advice? Don't worry too much about your competitors. Focus on carving your own portion of the market and serving those customers the best you can.

There isn't a lot you can do to find this out, assuming that the SAAS isn't publically talking about their numbers.

If you're using the product yourself and you know what to look for, you can sometimes get lucky. For example, one of my competitors uses incremental ids for users, so whenever I want to check on their growth over a period I will just create a new account and see what number I am in the URL. You can also check network requests for any incremental ids.

Newer apps have moved towards using uuids for ids, which look more random (like 1aeea404cd) so it's not always possible. IndieHackers for instance, you would have no way of knowing what user # you are or what post # this is

Try also SimilarWeb and G2

try publicwww :)

It's a broad Q but if it's a paid SaaS you may check the invoice number. Most are numbered in order. If it's an app there are many platforms that will share estimates, like App Annie and sensortower.