GTmetrix vs. PageSpeed Insights - which tool provides more actionable insights for website speed optimization?

GTmetrix and PageSpeed Insights are both excellent tools for analyzing website speed, but they offer different features and insights:

GTmetrix

Detailed Performance Metrics: Provides a thorough analysis with a performance score (based on Lighthouse and Web Vitals) and detailed metrics like Fully Loaded Time, First Contentful Paint (FCP), and Time to Interactive (TTI).

Waterfall Chart: Offers a detailed waterfall chart that shows how individual elements load on your website, helping you pinpoint issues like slow-loading images or scripts.

Recommendations: Provides actionable suggestions, including caching recommendations, image optimization, and script deferral.

Historical Data: Allows you to track performance over time with detailed history and compare how changes affect speed.

Free & Paid Plans: Free version available with limited reports, and the paid version offers advanced features like more frequent testing and additional performance insights.

PageSpeed Insights

Google’s Official Tool: Analyzes site speed and provides scores based on Google’s Lighthouse and Core Web Vitals (Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS)).

Actionable Insights: Provides detailed recommendations on performance optimization like image resizing, efficient cache usage, and script optimization.

Mobile & Desktop Insights: Gives separate reports for mobile and desktop performance, allowing you to target optimizations for each.

Suggestions for Improvement: Focuses heavily on actionable Core Web Vitals metrics that impact Google rankings, such as LCP, FID, and CLS.

Free Tool: Completely free with no limitations on usage.

Conclusion:

GTmetrix offers a more detailed view of website performance, with a focus on load times, a waterfall chart, and historical data. It's great for pinpointing issues and tracking improvements over time.

PageSpeed Insights is ideal if you want to focus on Core Web Vitals and optimize your site based on Google's SEO standards. It’s more targeted towards improving Google’s ranking factors for speed and user experience.

For actionable insights focused on Google's optimization criteria, PageSpeed Insights is better. However, for detailed performance tracking and historical comparisons, GTmetrix provides a more comprehensive analysis.

>> Let’s review some of the top performance testing features of PageSpeed Insights and GTmetrix :

PageSpeed Insights

• Cost: Free to use.
• Focus Areas: Analyzes four key areas: Performance, Accessibility, Best Practices, and SEO.
• Core Web Vitals Assessment: Provides metrics for Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS) based on a 28-day collection period.
• Performance Metrics: Includes measurements for First Contentful Paint (FCP), Largest Contentful Paint (LCP), Total Blocking Time (TBT), Cumulative Layout Shift (CLS), and Speed Index.
• Device Analysis: Supports analysis on desktop and mobile, but device selection is not customizable.
• Testing Options: Limited; does not allow choosing device, location, or connection type.
• HTTP Requests: Does not provide a detailed list of HTTP requests.
• Recommendations: Offers actionable suggestions organized into over 35 categories to improve performance.

GTmetrix

• Cost: Paid tool with several subscription plans.
• Focus Areas: Evaluates website Performance and Structure.
• Core Web Vitals Report: Includes insights into key metrics like LCP, TBT, and CLS.
• Performance Metrics: Covers First Contentful Paint (FCP), Time to Interactive (TTI), Speed Index, Total Blocking Time (TBT), Largest Contentful Paint (LCP), and Cumulative Layout Shift (CLS).
• Device Analysis: Allows testing on both desktop and mobile, with the ability to select specific devices.
• Testing Options: Offers customization for testing, including device selection, test location, and connection speed.
• HTTP Requests: Provides a detailed Waterfall Chart for HTTP requests, allowing precise resource analysis.
• Additional Features: Includes monitoring capabilities, historical performance tracking, and comparative analysis for tracking improvements.

For beginners or those focusing on SEO and Core Web Vitals, PageSpeed Insights is highly recommended also it is free for use.

Let’s review some of the top performance testing features of PageSpeed Insights and GTmetrix.

PageSpeed Insights

• It is free to use
• We can test website in four key areas: Performance, Accessibility, Best Practices and SEO
• Core Web Vitals Assessment (LCP, INP and CLS) - report for 28-day collection period
• Performance metrics for First Contentful Paint, Largest Contentful Paint, Total Blocking Time, Cumulative Layout Shift and Speed Index
• Analysis on desktop and mobile devices (we cannot choose device)
• It does not offer any options for testing 
• No list for HTTP requests files
• It provides actionable recommendations and organizes them into more then 35 categories.

GTmetrix

• Usage is paid and there are several plans
• We can test website for Performance and Structure
• Core Web Vitals report
• Performance metrics for First Contentful Paint, Time to Interactive, Speed Index, Total Blocking Time, Largest Contentful Paint and Cumulative Layout Shift 
• Analysis on desktop and mobile devices (we can choose device for both mobile/desktop)
• Offers testing options like select device, location, connection type
• Waterfall Chart (HTTP requests)
• It provides the option of monitoring and comparative analysis

I recommend using PageSpeed Insights because it is a free tool provided by Google.