Uptime monitoring

Reviewing 3 freemium website uptime monitoring services

Do you know whether your website is currently accessible from different locations around the world? Site24x7, StatusCake, and Uptime Robot all try to answer that question by automatically checking your website and keeping an eye out for trouble. But which service does the best job at it?

All of these services work more or less in the same way. Users create monitors by adding IP addresses or URLs and configuring some condition

Each service offers some unique features and they each offer different check-intervals and numbers of monitors. I’ll focus on some specific features common to each service and then go through pricing and service offerings before I get to the conclusion towards the end.

Incident reports

When something does go wrong with your website you want to know what happened so you can best assess how to fix the problem quickly. The more detailed the report the more likely you are to quickly identify and resolve any unexpected issues.

Site24x7 gives you a lot of details when something is amiss including a screenshot of the webpage (or a browser’s error page), traceroute and DNS anomalies, and ping response times. These are all neatly packaged in a per-incident Root Cause Analysisreport.

StatusCake can display traceroute information in an unfriendly JSON format but otherwise leaves you guessing at what might be wrong. I’ve set up a few monitors with StatusCake that never seem to get started and I couldn’t figure out why they were always reporting the server as down even though it was most definitely up. More on this in the “False positives” section below.

Uptime Robot can only tell you if your service is up or down. There is no details offered to help you identify and troubleshoot any service issues. I’ve contacted their support team asking about one specific incident, and was told “We are working on introducing more logs and reports regarding […] downtimes.

Response time

Website loading performance is super important and a factor in web search rankings. Keeping an eye on performance over time is important as it will let you know if you deployed a stupid change to your website that ought to be reverted.

Site24x7 doesn’t produce any reports except from average response times for the last 24-hours on the free tier, but produces by far the best report on their paid tier. The reports can be filtered per day, week, or custom period and you can see a separate report per testing location. Each performance report shows you DNS resolution time, connection time, and how long it took to receive the first and last byte. They also assign your website an Application Performance Index score (Apdex) per-location, which is an easy number for you to monitor over time. Based on your server’s response time, they will also produce a Busy Hour report that shows very accurately when your website receives the most traffic by hour of the day or day of week. (Slight Future receives the most traffic on Wednesdays when the email newsletter is sent out.)

StatusCacke produces the prettiest reports of the bunch and it can be broken down by hour, day, week, or year. However, they don’t differentiate between test locations so repose times will fluctuate from check to check, and they don’t break it down to total averages or averages per location.

Uptime Robot gives you last 24 hours on a graph and the average response time from one location. No historical data.

Mobile, apps, and notifications

Site24x7 has the only working official app for Android app out of the three evaluated service providers. Their app for iOS is prettier and seems to have received all of the developers’ love. Acceptable mobile website but with limited feature set. The design of their website and apps suggests that a design freeze went into effect around 2008.

StatusCake also has an official app for Android and its description advertises mobile notifications when monitors go down. However, the Android app seems to have been abandoned in October 2014 and it’s no longer possible to login to the app and it’s just sitting on Google Play Store collecting negative reviews. There is no app for iOS, but they have a mobile friendly website. The mobile website is a bit underdeveloped, though. It’s not possible to see the uptime or load averages for the last monitor in the list because it’s covered up by a fixed navigation bar at the bottom of the screen. The data tables are a bit crammed but it’s absolutely usable if your website goes down and you need to take a quick peek at it.

There are a few third-party options for apps that use Uptime Robot’s API. None of them are all that great, have received good reviews, nor are all that reliable. Even though app developers are supposed to use API keys from Uptime Robot, some also ask for your account password. An official app would have felt safer, even if it was just a web wrapper with native notification support. From glancing at the iOS App Store, the situation is mostly the same there. Their mobile website is minimalistic to match the service’s feature set.

Uptime Robot can, however, integrate with Twitter and sent you direct messages which will trigger a notification from the Twitter app. This is by far the best experience I’ve found for mobile-integration of Uptime Robot and it will work with Twitter on Windows Mobile, Android, and iOS.

False positives

StatusCake has got some serious problems. I see their monitors connect to my site, fetch a working web page that meets all criteria, complete the TCP connection, and still report 0 % uptime for that website. Other pages from the same webserver work just fine. With very little feedback in their incident reports, it’s hard to say what is going on, and StatusCake’s support haven’t been able to identify the problem either.

I’ve actually used Uptime Robot for two years already. However, the service started randomly firing false positives a dozen times or more per day following a server upgrade from an Nginx server with SPDY protocol support to an Apache httpd server with standard HTTP/2 protocol. I’ve contacted Uptime Robot, and they say it’s caused by an interoperability problem with their Node.js server. After a few days with constant alarms proclaiming that my websites where all but dead, I started looking for alternative providers. Prior to this, I’ve not had any issues with false positives from Uptime Robot.

Site24x7 has yet to give me any unexplained outages or problems, other than with IPv6. More on that next.

IPv6 capabilities

Traffic over IPv6 accounts for nearly 10 % of this website’s monthly traffic. Monitoring IPv6 uptime is becoming increasingly important to assure everyone has full access to a website.

Service name Ping monitor Web page check[1] IPv6-only domain Tests both dual-stack addresses[2]
Site24x7 No No Unreliable[3] Unreliable[3]
StatusCake No No No Unreliable[3]
Uptime Robot Unreliable[3] No No No

[1] Directed test at IPv6 address using literal-address format (RFC-2732).

[2] For a domain with IPv4 and IPv6 records, both versions should be tested to ensure availability.

[3] Some test locations support IPv6, others don’t – resulting in constant up/down alert triggers. No IPv6-aware control over test locations to make it more reliable.

Ouch. This isn’t looking good for any of the services. The user interface for managing monitors is also behaving inconsistently and can be very confusing. IPv6 support has clearly not been on anyone’s mind when validating user input. After having a quick look at other options on the market, the story is the same with all but the most expensive options. These are priced far out of my range.

I’ve contacted Site24x7 and StatusCake regarding their lack of IPv6 support. Site24x7 have answered all my other support inquiries but have chosen to ignore those mentioning IPv6 completely. StatusCake have acknowledged the problems and say they will work on it within weeks or months.


Site24x7 takes you from 10-minute intervals to 5-minute intervals for 5 USD per month. Both the Free and Basic tiers only include 5 monitors, but the next level up gives you 10 for 9 USD. All of Site24x7’s plans are very conservative with the number of monitors they give you. The killer feature you get as a paying Site24x7 user is the excellent and detailed performance and uptime reports from several locations worldwide.

StatusCake gives you an unlimited number of 5-minute interval monitors for free, and charge 25 USD per month to upgrade to 1-minute intervals. They could benefit from having more price tiers available with a limited number of one-minute monitors for smaller websites. Hook’em while they’re young.

Upgrading Uptime Robot takes you from 5-minute intervals to 1-minute with 1-year log retention for 6 USD per month. Both the free and paid plan includes 50 monitors, but you can buy as many paid subscriptions you want to add more monitors.


I’m going to stop using Uptime Robot in favor of Site24x7. Site24x7’s Basic paid tier’s performance reports over time are well worth the monthly charge and really sets it apart from the other services. They will let me evaluate server deployment changes and where in the world I should focus performance work. These reports require a paid subscription, and without the reports the service is essentially the same as Uptime Robot’s. Site24x7’s mobile apps give them a good edge on their competition, even on the free tier.

StatusCake charges a premium price for what appears to be a broken product for the time being. Their prices aren’t competitive compared to the two other services I’ve looked at, but they are competitive when compared to more expensive options in the same market. I expected to like them above the two other options as their website has the prettiest visuals of the bunch. Site24x7 has a worse interface and very outdated visuals, yet their service offer more data value and have proven far more reliable.

None of these services has good IPv6 service support, and I’m likely to change my preference towards whoever first adopts full support for IPv6. Given the business these services are in, not supporting IPv6 stopped being an option when the web hit 5 % IPv6 traffic four years ago.

Honorable mentions: These are all cheaper alternatives to Pingdom; which is the most popular uptime monitoring service at the time. However, Pingdom have dropped their free tier and their prices really need challenging as automating a few ICMP-pings-as-a-service shouldn’t need to be expensive.

4 thoughts on “Reviewing 3 freemium website uptime monitoring services”

  1. I’ve also tried using monitoring services for an IPv6-only domain (using a dynamic dns provider). My experience is different however from yours. I did not try Site24x7, but with UptimeRobot the site shows 100% uptime (until manually taken down) and everything seems to work perfectly for my IPv6-only domain.

    With StatusCake however the site shows about 80% Uptime and in the “Downtime causes list” it shows a mixture between “timeout / connection refused” and “domain not found” messages. Strangely, StatusCake – just like UptimeRobot – does not notify me of a downtime even though it claims the host is only 80% up until I manually take it down. The problem that some of their testing hosts are not IPv6 capable seems to be caught before alerting me by the “3 confirmation servers” I guess.

    So regarding IPv6-Only Domains I would summarize: UptimeRobot works, StatusCake is 80% there 🙂
    (my tests were done between September 10 – September 13 2016)

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