What are the tools to monitor website performance?

What is Website Performance Monitoring 
In order to prevent performance and availability issues, your enterprise needs to be able to examine each part of your web infrastructure in real-time. Now the question is how do you do this? By using website monitoring tools you can constantly observe website’s performance. Performance monitoring involves the measurement of performance over time against indicators of performance or key performance indicators or KPIs. The ultimate goal of website performance monitoring is to supply end users with a top quality end-user experience. Monitoring tools give administrators the information they need to quickly figure out issues which negatively impact an website’s performance. Picking the right website monitoring service is difficult. They perform regular tests and alert you whenever your site is down, making it easier I am going to enlist some best tools. Continue reading till end.
List of Website Performance Monitoring 

1. Sematext.com: Sematext Cloud is an all-in-one log management and monitoring solution that provides end to end visibility and observability. When it comes to website monitoring, we offer Sematext Experience, our real user monitoring (RUM) solution, and Synthetics, our synthetic monitoring tool. With this tool you’ll get a report on the actual experience and satisfaction of your users while providing key pieces of information as to how your website or application is performing in different locations, devices, or different connection speeds. Every plan has a risk-free, 30-day trial that does not require any credit card to be added. It also offer granular control over what you pay for as every product is individually priced. This way you can pay only for the products and features he needs.
2. Uptime Robot: It’s probably one of the greatest best value for money solutions, especially if you are looking for just a simple tool that will tell you when your services are down. The free account gives you 50 monitors which are plenty enough for most small websites or web apps along with 5-minute monitoring intervals from 12 locations around the globe and 2 months of log storage. As the name suggests it focuses on performing synthetic checks on your site and APIs every 5 minutes and provides alerts through a number of integrations with tools like Slack, Pagerduty, OpsGnie, Telegram, and VictorOps.
3. Pingdom: Pingdomis an uptime monitoring service that will send out detailed alerts whenever an application or website goes down. It is in the list of the top monitoring services by offering a wide range of capabilities, including website performance monitoring. While you are able to monitor a large number of endpoints, performance seems to suffer especially when viewing individual items. Its instantaneous alerting system makes it unique. In this SMS and email notifications are available.
4. New Relic Browser: With New Relic Browser you can expect more modern metrics that are centered around the users’ needs rather than just plain old load times. Browser will help you understand how code changes impact end customers by monitoring contentful paint times and interactivity metrics. This tool provides you full Support for Google’s Core Web Vitals and advanced alerting systems. 
5. AlertBot: It is a monitoring platform that integrates website monitoring alongside web application, mobile website, and service monitoring capabilities. In addition to checking a website’s availability, AlertBot examines critical website elements (such as scripts and interactive code) and scans for errors.