OpenSpeedTest

OpenSpeedTest is a free and open-source HTML5 network performance estimation tool written entirely in vanilla JavaScript. It uses only built-in web APIs like XMLHttpRequest (XHR), HTML, CSS, JS, and SVG — no third-party frameworks or libraries are required.

Started in 2011, OpenSpeedTest has grown into a reliable and widely-used tool for measuring internet connection speed. It supports all modern browsers across desktop and mobile, providing accurate measurements of download speed, upload speed, and latency without any plugins or installations. The test automatically selects the nearest server for optimal results.

Being fully self-hostable, OpenSpeedTest can be deployed on any web server, making it ideal for organizations that need private, internal network testing without relying on third-party services. Its lightweight design — a single HTML page with embedded CSS and JavaScript — makes deployment trivial.