Let me tell you about a recent performance optimization challenge we faced at Pagecloud and how we tackled it.
It involved Interaction to Next Paint (INP) a crucial Core Web Vitals metric and a surprisingly subtle culprit: the viewport meta tag.
This isn’t your typical run-of-the-mill performance tweak; it’s a into the nuances of web responsiveness.
Understanding INP: Beyond First Input Delay (FID)
INP or Interaction to Next Paint measures the responsiveness of your website to user interactions. Unlike First Input Delay (FID) which only looks at the very first interaction INP considers all interactions a user makes during their session – clicks taps keystrokes – providing a more comprehensive view of the user experience. A high INP translates to a sluggish frustrating experience for your visitors directly impacting user satisfaction and potentially your bottom line.
Imagine a user trying to navigate your site.
They click a button and there’s a noticeable delay before anything happens.
This isn’t just annoying; it breaks the flow of their interaction.
A high INP indicates the presence of such delays across numerous interactions painting a clear picture of poor responsiveness.
This is where INP significantly improves upon the older FID metric; it captures the full picture of interaction delays rather than just the first one.
In a complex web application with many interactive elements FID could appear fine while INP could expose a widespread problem with responsiveness.
Thinking about it this way INP offers a far more holistic and realistic representation of the user’s experience.
It’s the cumulative effect of all those small delays that truly matters.
The Importance of Core Web Vitals and Lighthouse
INP is part of Google’s Core Web Vitals a group of essential metrics designed to measure user experience.
Want to learn more about the unexpected culprit of our 200ms INP spike? Dive into the blog post and discover the hidden culprit! 🤯
These aren’t just some arbitrary numbers; they directly impact your site’s ranking in search results and more importantly the satisfaction of your users.
Besides INP Core Web Vitals also include Largest Contentful Paint (LCP) which measures loading performance and Cumulative Layout Shift (CLS) which assesses visual stability.
These metrics when optimized create a smooth engaging user experience.
Google’s Lighthouse tool is your best friend in analyzing and improving your Core Web Vitals.
Lighthouse provides a detailed breakdown of your website’s performance offering specific recommendations to address any issues.
It’s more than just a score; it’s a diagnostic report pinpointing areas for improvement.
A high Lighthouse score isn’t just about SEO bragging rights; it reflects a truly well-optimized website that delivers a consistently positive user experience leading to higher engagement and conversion rates.
It’s about building a site that genuinely delights its visitors.
The higher your Lighthouse score the smoother the user experience is likely to be.
It’s a holistic metric of how well your site performs looks and feels to the end-user.
Our INP Challenge: A 200ms Mystery
Recently our team at Pagecloud observed a concerning spike in INP.
Chrome’s Web Vitals tool flagged a 200ms increase pushing our INP score into the “needs improvement” territory and dragging down our overall Lighthouse score.
This wasn’t just a minor blip; it was a significant performance regression that demanded immediate attention.
This impacted not only our own internal scores but could have potentially impacted our customers’ website experiences highlighting the crucial need for vigilant monitoring of key performance indicators.
We immediately sprang into action to pinpoint and resolve the issue working diligently to maintain a consistently positive user experience.
The Culprit: A Fixed Viewport Width
The root cause was unexpected: a fixed viewport width defined in the HTML meta tag <meta name="viewport" content="width=468">. This seemingly innocuous tag designed to control the scaling and dimensions of the viewport was causing significant interaction delays.
Want to learn more about the unexpected culprit of our 200ms INP spike? Dive into the blog post and discover the hidden culprit! 🤯
It’s important to note that although the tag in itself is not inherently bad practice its impact within our specific context led to noticeable performance issues.
Removing the tag was not a viable solution given that it would have required updating thousands of customer websites – a logistical nightmare.
We needed a more surgical approach one that would address the problem without causing widespread disruption.
We couldn’t simply delete the line of code; we needed to find a way to mitigate its negative impact without affecting the functionality of the existing websites.
This required careful consideration and testing to avoid any unintended consequences.
This made it crucial to find an alternative solution; one that would rectify the problem without disrupting the countless websites using the existing viewport settings.
The Solution: CSS to the Rescue
Our solution involved adding the CSS property touch-action: manipulation; to the <body> element of affected pages.
This seemingly simple addition made a world of difference.
The touch-action property controls how the browser handles touch events specifically preventing default browser behaviors that might interfere with responsiveness essentially improving the way the user interacts with the page on touchscreen devices.
The inclusion of this property enabled us to improve responsiveness enhancing the user experience and reducing unnecessary delays.
By adding this CSS rule we effectively addressed the interaction delays caused by the fixed viewport width.
We effectively circumvented the problem without altering the underlying viewport settings.
The result was a dramatic improvement: our INP dropped to approximately 32ms a phenomenal improvement from the previously reported 200ms.
This substantial reduction in INP directly translated to an improved user experience.
Our Lighthouse score also saw a welcome increase further reinforcing the positive impact of our solution.
This success underscores the importance of careful and strategic implementation to achieve optimal performance results.
A Curious Mystery and the Importance of Continuous Monitoring
While we successfully resolved the INP issue the exact reason why the fixed viewport width caused such a significant delay remains somewhat of a mystery.
Our initial hypothesis pointed to an older mobile browser tap delay issue but the available documentation was scarce and outdated.
This highlights the constantly evolving nature of web development and underscores the importance of keeping a watchful eye on emerging trends and performance issues.
This experience is a valuable reminder of the critical role of continuous performance monitoring and optimization.
Even seemingly harmless code can have unexpected consequences and the only way to guarantee optimal performance is to consistently monitor key metrics like INP LCP FID and CLS.
We must remain vigilant in monitoring performance metrics.
Technology is ever-evolving; the issues we face and the solutions we implement today might evolve over time.
The Bigger Picture: User Experience and SEO
Improving your site’s performance isn’t just about technical metrics and SEO scores; it’s about providing a positive user experience.
A faster more responsive website leads to happier users increased engagement and ultimately higher conversion rates.
Google acknowledges this and incorporates Core Web Vitals into its search ranking algorithms.
Beyond the Numbers: A User-Centric Approach
Focus on the user experience; everything else falls into place.
A high Lighthouse score is a great indicator but it’s the user’s actual experience that truly matters.
Focus on providing a smooth seamless experience.
Want to learn more about the unexpected culprit of our 200ms INP spike? Dive into the blog post and discover the hidden culprit! 🤯
This isn’t about ticking boxes; it’s about creating something people genuinely enjoy interacting with.
Remember optimizing for performance is an ongoing process.
New technologies and browser updates continuously emerge potentially introducing new performance challenges.
A robust monitoring strategy coupled with a willingness to adapt and experiment is the key to maintaining a high-performing website.
Stay up-to-date be proactive and remember that the user should always be the focus of any design decisions.
Final Thoughts
Our INP journey taught us a valuable lesson: even small changes can have a significant impact on website performance.
The interaction between viewport settings and INP isn’t widely documented making our experience a potentially valuable contribution to the community.
Let’s remember that consistently monitoring performance metrics utilizing tools like Lighthouse and always prioritizing user experience will make our websites faster and more delightful to use.
It’s about a continuous process of learning adapting and optimizing to provide the best possible experience to our users.
The website development journey is full of such lessons; embrace the challenges and let them guide your way towards creating highly optimized websites!