Websites used to be simple. A few pages of text and images held on a Web host were easy to monitor. These days, things are a lot more complicated. Content delivery networks and caching servers hold copies of the same website on many different servers around the world to speed up delivery. Services, such as widgets or tracker libraries mean that content from other servers needs to be read into a web page as it is loading into a browser. Websites are no longer delivered from one single server.
Now that the successful delivery of a web page requires many connections to different servers in different places around the globe, there are a lot more things that can go wrong and prevent that page from loading. Monitoring a website yourself to see if it is available from your offices is not enough. You need to check that people all over the world can see your site.
Asking people you know in different countries to look at your website is a non-starter and you can’t expect the general public to contact you if your site isn’t available in a faraway place. So, you need a system that performs automated checks on your site from many locations.
Here is our list of the seven best synthetic monitoring tools:
- Pingdom Synthetic Monitoring EDITOR’S CHOICE A bundle of uptime, response time, and web transaction monitoring that launches tests from more than 100 locations. It includes programmatic and browser-based checks.
- SolarWinds Web Performance Monitor (FREE TRIAL) An on-premises website monitoring system that includes uptime and response time reports plus root cause analysis tools linked to transaction monitoring.
- Dotcom-Monitor (FREE TRIAL) A synthetic monitoring platform that offers a range of browser-based availability and performance tests for websites and web services.
- Datadog Synthetic Monitoring Uptime, response time, and transaction monitoring from multiple locations with CI/CD software development testing and rollout features.
- Site24x7 Synthetic Monitoring Offers a range of synthetics from Ping-based availability checks through to browser-based transaction monitoring from 110 locations.
- Paessler PRTG An on-premises monitoring system that includes the services of remote servers for multi-location synthetic web performance monitoring.
- Google PageSpeed Insights A free online tool for on-demand response time monitoring with detailed analysis of the causes of poor performance.
You can read more about each of these options in the following sections.
Synthetics for websites
Human website checkers cost a lot of money. The only viable method to make sure your website is available everywhere is to use automatic processes driven by software. This is what synthetic monitoring does.
Synthetic monitors remove the need for real people to check on your site from different locations. They emulate the actions of users and report back on statuses. An automated process doesn’t accidentally miss out on checks or forget to write things down. Automated monitoring is free from human error.
There are three levels of synthetic monitors:
- Uptime monitors
- Response time monitors
- Web transaction monitors
An uptime monitor just checks that your site is available. These checks are launched from several locations around the world and they occur repetitively. Some businesses set their uptime monitoring frequency at one minute, while others can work with five-minute intervals or even longer.
A response time monitor will report on how long important elements in a page took to load – these are also called load time monitors. This is because you don’t just need to know how long your web server took to reply to a request; you need to know how long it takes for the banner to appear and also elements such as images. It is important to know when the interactive features on a page, such as links, become active. Generally, uptime monitors work on websites, and response time monitors examine Web pages.
A Web transaction monitor is also known as a Web performance monitor or a Web application monitor. This checks on the elements in a page and makes sure they are working individually and as a suite. The proper way to make sure that a Web page works the way you expect it to is to get a real person to go through all of the utilities in your site, such as input forms or video players, and activate them. However, you don’t want to be reliant on members of the public to email you and tell you that an important part of the site is broken. This is because people won’t bother to do that, they will just move on to a rival site and buy its goods and services.
A Web transaction monitor implements a test script that runs through a sequence of actions on your live site to make sure that any users that arrive will be able to successfully complete an important task, such as ordering a product.
Synthetic monitoring modes
Some of the tasks that check on your live website can be done without actually loading any pages from it. For example, a system doesn’t need to load a page into a browser if it is just checking that the DNS entry for the site is correct or that the SSL certificate is valid. These synthetic monitoring services operate programmatically and are also known as API testers.
Uptime monitors in particular don’t need to get a full page from your site in order to report on its status.
Web transaction monitoring wouldn’t be thorough if a WebCrawler performed it. You can only get a proper user’s eye view of a site if it loads into a browser, so all Web transaction monitors are browser-based. Response time monitors are between these two scenarios because some elements can be tested just by examining the code for a Web page without actually having to render it. Others require the page to be loaded into a browser in order to measure its load time.
So, there are two modes of synthetics – API testing and browser-based tests. Browser-based tests are more expensive than API tests.
Synthetic monitoring frequency
Some factors of a web server’s performance are more vital than others. For example, if a Web server has gone offline, there is no point in launching a Web performance test. So, the different types of tests are performed at different frequencies. The optimal frequency for each type of test is:
- Uptime monitoring: 1 minute
- Response time monitoring: 5 minutes
- Transaction monitoring: 15 minutes
Uptime monitoring is the cheapest form of website checker and so can be performed more frequently without breaking the bank. It is also the most fundamental test that you need. As transaction monitoring is the most expensive type of test, businesses with little money to spend will lengthen the frequency of those tests.
The best synthetic monitoring tools
In this report, we look at synthetic monitoring services that offer uptime monitoring, response time monitoring, and Web transaction monitoring. Some services offer all three in a bundle, while others focus on just one category of synthetics. The common thread is that they will let you know when problems arise without you having to wait for visitor counts to drop in order to figure out that something is wrong.
Pingdom Synthetic Monitoring is a cloud service that operates from more than 100 data centers around the world. As the service’s name suggests, its creation was based on the application of Ping to test the availability of servers. Ping can operate across networks or the Internet and it is the Internet’s performance that is the particular focus of Pingdom.
Ping is very widely used for website availability monitors and it is a synthetic monitoring technique. Pingdom is more than just Ping, however, because it runs a range of tests from a selection of remote sites to examine load times and transaction performance on Web pages.
The Pingdom Synthetic Monitoring service bundles together uptime, response time, and transaction monitoring, giving the subscriber the option of choosing how many of each type of test to run every month. Uptime monitoring is offered at ten times the quantity of advanced tests in each package. The advanced test category covers response time and web transaction monitoring.
Features in the Pingdom package include downtime alerts that notify you when your website is uncontactable and logs the downtime periods. A Timeline Metrics screen in the dashboard ranks page elements by lag time so you can see which features are dragging down the performance of your Web pages. The Transaction Monitoring screen allows users to set up test scripts that walk through user tasks in a site.
Pingdom also offers a Real User Monitoring service and you can get a 14-day free trial that includes both synthetic monitoring and real user monitoring.
Pingdom is our top pick for synthetic monitoring because it operates from 100 locations worldwide. So, you will know immediately if your site becomes unavailable in one part of the world even though it seems to be working fine when accessed from your offices. An alerting and logging mechanism in the service means that you don’t have to constantly watch the monitor, but you will be informed as soon as problems arise. Response time monitoring and transaction monitoring features mean that you can examine the performance of every element on every page of your site, not just the overall availability of the website. Start 14-day Free Trial: pingdom.com/sign-up/ OS: Cloud-based
Pingdom is our top pick for synthetic monitoring because it operates from 100 locations worldwide. So, you will know immediately if your site becomes unavailable in one part of the world even though it seems to be working fine when accessed from your offices. An alerting and logging mechanism in the service means that you don’t have to constantly watch the monitor, but you will be informed as soon as problems arise. Response time monitoring and transaction monitoring features mean that you can examine the performance of every element on every page of your site, not just the overall availability of the website.
Start 14-day Free Trial: pingdom.com/sign-up/
If you are more interested in a monitoring tool that you can install on one of your own servers and run in-house, the SolarWinds Web Performance Monitor is probably your best option. This monitoring system is able to perform constant availability checks on all of your websites.
The SolarWinds Performance Monitor includes synthetic monitoring and real user monitoring tools and there is no per-transaction charge, so you can run tests as often as you like without worrying about the cost.
The highest frequency available for uptime monitoring is five minutes. Those availability checks continue around the clock and any failed connection attempts provoke alerts and a status report, logging the total downtime period. The transaction monitoring and response time testing functions of the software include a drill-down root cause analysis tool to help you fix performance issues quickly.
Response time testing covers a very detailed list of services and events as they render in a browser. This produces a list of load times that are tracked over time, so a one-off infrastructure problem doesn’t make you think that there is a long-term serious problem.
SolarWinds offers the Web Performance Monitor on a 30-day free trial. The software for this system installs on Windows Server.
Dotcom-Monitor offers a range of synthetic monitoring packages that each specialize in a specific type of test. There are Web Services, Web Pages, Web Applications, and Stress Testing.
The Web Services Monitoring plan issues Ping and GET/POST tests from a choice of 30 locations to test availability. These are browser-based tests and they can be aimed at essential services, such as HTTP and HTTPS to check on the availability of the site. There are also tests for APIs and SSL validity.
The Web Pages Monitoring tests are also browser-based and they check on the response times of elements on a page. It checks on content validity and creates a waterfall diagram of dependent applications becoming responsive on a page. This service will also check SSL certificate validity and DNS entries.
The Web Applications Monitoring package offers the ability to step through code and create testing scripts that exercise interactive elements in a Web page. It also validates content and reports on response times.
The Stress Testing service generates volumes of synthetic connection demand to check on the capacity of your Web server.
Whichever plan you choose, you pay for the service by subscription and the price you pay depends on the number of tests that you want to run during the month. You can get a 30-day free trial of all of Dotcom-Monitor’s services.
Datadog is a cloud service that monitors website performance from several locations around the world with synthetics. Uptime checks work with TCP requests, which enable them to check on DNS servers and SSL certificates at the same time. The service also includes an HTTP-based check to ensure that a web server is not only operating but that it can locate and deliver the pages of your site.
Transaction monitoring with Datadog launches browser-based tests, following an action script. The results of each run are displayed as a waterfall graphic that makes the performance of each service that gets triggered by the action clearly. It is easy to see from this visualization which elements are slow and whether any services failed. Datadog also includes an automated transaction testing service that is based on AI machine learning. It explores all of the interactive elements in a page and tests them in combination.
A subscription for programmatic tests cost $5 per month per thousand test runs and browser-based test cost $12 per month per thousand. You can get an unlimited 14-day free trial of Datadog Synthetic Monitoring.
Site24x7 operates its Synthetic Monitoring service from 110 data centers around the world. Its services include both Ping-based tests and browser-based synthetics to provide uptime, response time, and transaction monitoring systems.
The Synthetic Monitoring service is part of the Site24x7 Website Monitoring package. This package includes a number of site checks, which include an SSL certificate monitor, a DNS monitor, and a domain expiry monitor. There is also a system to check the code of a site for errors, called the Website Defacement Monitor. Response time monitoring includes statistics on DNS fetch times, connection establishment times, first byte arrival time, download time, and SSL handshake time.
There is a free version of the Site24x7 Website Monitoring package, which is limited to monitoring up to five websites. There are four paid plans: Starter, Pro, Classic, and Enterprise. Starter, the cheapest plan, includes the ability to monitor up to ten websites. You can get a 30-day free trial for any of the four paid plans.
Paessler PRTG is a package of many monitors for networks, servers, and applications. Each monitor is called a “sensor” and there are some that specialize in website monitoring. The most important of these are the HTTP Sensor, the HTTP Transaction Sensor, and the HTTP Full Web Page Sensor.
The HTTP Sensor is an uptime monitor that tests DNS services as well as server availability. The HTTP Transaction Sensor is a web performance monitor that runs action scripts on a Web page through a browser. The HTTP Full Web Page Sensor is a response time monitor that reports on the load times of different elements in a web site.
Paessler PRTG installs on Windows Server and it is offered on a 30-day free trial. This trial has no limit on the number of sensors that can be activated. So, it gives you an opportunity to try each available monitor and work out exactly which monitors you really need. When you buy the software, its price is levied according to the number of sensors to be activated.
PageSpeed Insights is a free service from Google that lets anyone see the response time statistics. The service is very easy to use. It is presented as a website and the user just needs to enter the address of a Web page in the home page’s only data entry field.
The service produces very detailed results and gives the page an overall score for response times. Score ranges are color-coded as bad, okay, or good. Below the overall score, the user sees a list of different response times from the examined page. Below that, the service recommends improvements that could improve the response times of the page. Two tabs at the top of the results section switch between results for responses on desktop computers and responses on mobile devices.
This is an excellent tool for those who want to analyze a Web page. However, this is an on-demand response time monitor so it won’t help you to check on your website automatically.