We examined the response times of nine popular content management systems and eCommerce platforms to user actions, as measured by a key metric called Interaction to Next Paint (INP).

INP is one of Google’s Core Web Vitals, which measures how quickly a page responds when someone clicks, taps, or types. This matters a lot for user experience—slow response times can frustrate visitors and hurt engagement.

Because of its importance, the HTTP Archive tracks INP performance across different CMS platforms. Based on their data, here’s how the top CMSs and eCommerce tools stack up in terms of speed and responsiveness.

What Is Interaction to Next Paint (INP)?

INP is a way to measure how quickly a web page reacts when someone interacts with it. It tracks the delay between a user clicking, tapping, or pressing a key—and the moment the page visibly responds. In short, it shows how responsive and smooth your website feels during real use.

INP gives a better picture of how responsive a website really is—much more so than the older metric it replaced, called First Input Delay (FID). While FID only looked at the first interaction on a page, INP tracks all clicks, taps, and key presses. Then, it highlights the slowest meaningful response time to give a clearer view of how the site performs during an entire visit.

An INP score gives a good idea of how responsive a page usually is. To keep the results accurate and fair, any extreme or unusual delays are left out. This way, the score reflects what users typically experience during the slowest—but still realistic—moments on the site.

When a web page responds slowly, it can frustrate users and make them leave before doing anything. On the other hand, quick and smooth interactions keep visitors happy, encouraging them to stay longer, engage more, and even convert into customers.

How INP Scores Are Rated?

INP scores fall into three simple categories:

  • Good: If your page responds in 200 milliseconds or less, you’re in great shape.
  • Needs Improvement: If the response time is between 201ms and 500ms, there’s room to do better.
  • Poor: Anything over 500ms means your site is likely frustrating users and needs serious attention.

Fast responses keep users happy—so aiming for “Good” is always worth it!

How Top CMSs Stack Up in INP Metrics (And Why It Matters)

The newest INP data is in—and it’s good news (mostly). All major content management systems saw a slight boost in performance from June to July. The improvements weren’t dramatic, but they show steady progress in making websites more responsive.

Joomla led the pack this month, with a 1.12% jump in the number of sites hitting a “good” INP score. WordPress wasn’t far behind, showing a 0.88% improvement. Wix followed with a 0.70% boost, and Drupal also made progress, increasing by 0.64%. These small but steady gains show that platforms are moving in the right direction when it comes to responsiveness.

Duda and Squarespace also made progress, with increases of 0.46% and 0.22%, respectively. While these numbers might seem small, even tiny improvements can make a noticeable difference in how smoothly users interact with websites. It’s great to see that every platform in this comparison is moving forward and improving user experience.

Which CMS Really Has the Best INP Scores?

Looking at monthly improvements shows who’s making progress, but it doesn’t tell us which CMS is the fastest overall. When we check the July INP results, the ranking changes—revealing a different picture of which platforms deliver the best responsiveness across the board.

Squarespace is currently in the lead, with 96.07% of its sites earning a good INP score. Duda comes in second at 93.81%. This is quite different from the usual Core Web Vitals rankings, where Duda often holds the top spot. But when focusing on one of the most important metrics—Interaction to Next Paint—Squarespace takes the crown as the best-performing CMS.

Wix and WordPress fall in the middle of the pack, with 87.52% and 86.77% of their sites achieving a good INP score. Close behind them is Drupal, sitting in fifth place with 86.14%—just a small gap separating it from WordPress.

Joomla comes in sixth place with an INP score of 84.47%. While it’s behind the top five, it’s not far off—just about two to three percent lower than Wix and WordPress. That’s still a respectable performance.

How Does Shopify Measure Up in INP?

Shopify is known for solid Core Web Vitals scores, but how does it stack up against these six popular CMS platforms? At first glance, it might seem like an unfair matchup since online stores often have extra features, images, and videos that can slow things down.

However, since platforms like Duda, Squarespace, and Wix also offer ecommerce options, comparing Shopify to them is actually quite fair and makes sense.

Among the shopping platforms we looked at, BigCommerce takes the lead with an impressive 95.29% of sites hitting a good INP score. Shopify follows with 89.58%, and WooCommerce comes in third at 87.99%.

BigCommerce clearly stands out as the top performer when it comes to this key responsiveness metric.

Verdict

INP is a valuable metric because it shows how quickly a web page responds, which directly impacts user experience. The latest data reveals that while all CMS platforms are making progress, Squarespace, BigCommerce, and Duda lead the pack with noticeably better performance.

Even though there are differences, every platform in this comparison has a high percentage of sites with good INP scores. Shopify, ranked fourth, trails the leader Squarespace by just 6.5 percentage points. Meanwhile, Joomla, at the bottom of the list, still has 84.47% of its sites achieving good INP scores.

Overall, these numbers highlight that no matter which platform you choose, users can expect a solid and responsive experience.

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