I've been using Pingdom's free plan to monitor one site for many, many years. I'm guessing that SolarWinds has had this in the plan for a while, as the free tier likely has very few conversions since going from free to paid is a bit of a jump to ~$10/month ($120/year).

For someone who just wants to know if a site is up or down, and has a dozen cheap or free services to choose from (I also sometimes use UptimeRobot), it's not a market Pingdom really caters to anymore.

Anyways, this is also the reason I built Server Check.in[1] a few years back[2]; mostly for my use, and it's been a fun ride! Building a distributed, microservice-ish thing over the course of 7 years has been interesting. Would love to answer questions about it if you have any.

[1] https://servercheck.in/ [2] https://news.ycombinator.com/item?id=4901350

What is the tech stack for Check.in?

I use WebSitePulse (https://www.websitepulse.com/). After the free trial, they offer a free plan. Unfortunately, they ping your target just once a day. The good thing about them is they don't offer prepaid plans - just pay for what you use at the end of the month.

Check out Freshping by Freshworks - offers 50 checks at 1 min interval & public status pages for free.

Disclaimer: I'm a maker of Freshping (https://www.freshworks.com/website-monitoring/)