YSlow Alternatives

GTmetrix is free, web-based website performance monitoring tool. With GTmetrix you can see how your site performs, reveal why it's slow and discover optimization opportunities.

Pingdom is a web-based tool for monitoring website performance and availability. Their service is used by over 30,000+ users including startups and 60% of the Fortune 500 companies. Pingdom can help digital marketers understand the impact performance has on reach and sales, or web developers and devops teams to identify bottlenecks and monitor impact of their latest push to production.

With WebPageTest you can run a free website speed test from around the globe using real browsers at consumer connection speeds with detailed optimization recommendations.

SEMRush is a search engine marketing toolset that is by millions across the globe. SEMRush provides tools for keyword research, competitor analysis, backlink reports and much more. The software is suited for small to mid-size search engine marketing firms or individual organizations looking to improve search engine rankings.

The Swiss Army knife of content marketing, Ahrefs is a set of SEO tools packaged as a service. With Ahrefs, content marketers SEO's can get detail search engine data about their domains, which can be used to further improve the visibility and reach online. The toolset is powered by AhrefsBot, a web crawler that crawls webpages and provide data to analyze both organic and paid results in search engines. Ahrefs is loved by content marketers across the globe, that use the tool for competitor analysis, backlink checking, SERP monitoring and much more.

Google Analytics is the world's leading analytics platform for web and application tracking. With Google Analytics, website and application owners can track user behaviour across their sites or applications, free of charge. Google Analytics provides valuable insight, like how long a visitor stays on page, what country it is from, what type of device it is using, and what links and pages the user it is interacting with. This data can then be used by domain owners and developers to improve content, navigation and structure of site to ultimately provide a better experience for the end user.

StatusCake is a web-based tool for uptime and performance monitoring of websites. The tool is both quick and easy to setup and provides and provides a free-for-life plan for up to 10 websites, with extra functionality for paid subscribers. With StatusCake, website uptime can be monitored through a sophisticated UI and alerts can be sent to third-party applications such as PushBullet Slack, Telegram, Discord, and many more.