WordPress has introduced block themes since version 6, and since then, it has been pushing users to use these themes.
In this post, we will compare the speed performance of Block themes and Classic themes and see how well they can handle real-world websites.

Block and classic themes have similar speed performance on desktop computers, but block themes lag behind on mobile devices by 10 to 15 points. Classic themes also load faster, with a speed index that is 0.5 seconds shorter on desktop and almost two seconds shorter on mobile.

Block theme vs Classic theme Speed Test

In this post, we compare the default WordPress theme, Twenty Twenty-Four, and the Spectra One theme (created by the same team behind the popular Astra theme) with three classic themes: GeneratePress, Blocksy, and Kadence.
We know that many of you are interested in using these themes for your online stores, so we also added the WooCommerce plugin and ran the speed test on a product page. We repeated the test three times for each theme and calculated the average score to determine the final ranking.

Twenty Twenty-Four

Twenty Twenty-Four, a new WordPress block theme, was released with WordPress 6.4. This theme is significantly faster than previous WordPress themes, and it includes a number of beautiful pre-designed patterns.

In speed tests, Twenty Twenty-Four scored 81 on mobile and 95 on desktop. The speed index of Twenty Twenty-Four is 5.8 seconds on mobile and 1.9 seconds on desktop.
While the scores are promising, this theme could be further optimized for mobile devices.

Spectra One

Spectra One is the most popular block theme for WordPress. While it is not required, installing the Spectra plugin will unlock all of the theme’s features.
In speed tests, Spectra One scored 96 on desktop and 86 on mobile.The theme’s desktop speed index is 2.1 seconds, while its mobile speed index is 5.2 seconds.

Overall, Spectra One is a good choice for WordPress users who want a stylish and customizable block theme. However, it is important to note that the theme could be optimized for mobile devices for better performance.


‌Blocksy is one of the most popular free WordPress themes. The paid version of this theme adds a lot of features, especially for online stores, but the free version is still very capable. In fact, I used ‌Blocksy to design this website!

In speed tests, ‌Blocksy scored an impressive 98 on both mobile and desktop devices. This means that it loads quickly and smoothly on all devices. The theme’s mobile speed index is 3.6 seconds, while its desktop speed index is 1.4 seconds.

Overall, ‌Blocksy is a great choice for WordPress users who want a stylish and functional theme that is also fast and responsive.


Kadence and Blocksy are two very similar WordPress themes. Some people even say that Kadence copied Blocksy’s features. However, Kadence is a reliable and fast theme with a lot to offer.

In speed tests, Kadence scored similarly to Blocksy, and even slightly better in some cases. However, I personally prefer the default appearance of Blocksy to Kadence. Ultimately, the best theme for you will depend on your individual needs and preferences.


If you are looking for the fastest WordPress theme, you can choose between the free and the premium versions of GeneratePress. However, the free version has very few features and is not very practical, while the premium version offers a lot of functionality and performance.
This theme is highly optimized for speed, but it may require some coding skills to customize it to your liking.

This theme has excellent results in the speed test, with 98 points on mobile devices and 99 points on desktop computers.

The speed index of this theme is also impressive, with 3.1 seconds on mobile devices and 1.2 seconds on desktop computers. There is a reason why this theme is known as the fastest WordPress theme!

Final thought

The table below shows the speed performance of the most popular block themes and classic themes. These results are based on my own server, so you may get slightly different outcomes on your server.

Theme nameMobile ScoreDesktop ScoreMobile Speed indexDesktop Speed index
Spectra One86965.2s2.1s
Twenty Twenty-Four81955.8s1.9s
Block theme vs Classic theme PageSpeed Score

The chart above shows that the classic themes perform better on mobile devices than the block themes. This is not to say that the block themes are bad or unsuitable for your final product, but rather that they require more optimization to work well.

If this article is difficult for you to read in text, you can watch the video version below.

What will happen to existing WordPress themes once Full Site Editing becomes the standard?

Existing WordPress themes will continue to work as they always have. However, users may need to switch to a block theme or enable Full Site Editing to take advantage of the new features and customization options.

Are there any performance differences between block themes and classic themes?

Generally, there should not be significant performance differences between block themes and classic themes. Performance is more likely to be influenced by factors such as the hosting environment, plugins, and overall website optimization. However, block themes may offer more efficient ways to manage and reuse design elements, potentially streamlining the development process.

Can I still use page builders like Elementor or Divi with block themes?

Yes, popular page builders like Elementor and Divi are working towards integration with Full Site Editing and block themes. Some page builders already offer compatibility with the block editor, allowing users to create and edit content using a mix of core blocks and custom page builder blocks. However, it’s essential to keep in mind that as Full Site Editing evolves, some page builder functionality may overlap with core WordPress features. Users should check with their preferred page builder for specific compatibility details and recommendations.

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Hi, my name is Maya and I’m a WordPress plugin developer. I created this website to share some of the helpful codes that I’ve used in my own projects.
If you’re looking for a custom plugin for your website, you can contact me by clicking on Hire a developer in the menu. I’d love to hear from you.

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