Website slow to respond to taps and clicks? Causes and fixes

Key takeaways

A website that is slow to respond to taps feels broken, even if it loaded quickly. The visitor presses the menu, a filter or a button and nothing happens for a noticeable moment. The cause is nearly always too much script running on the phone at once. Google measures this as Interaction to Next Paint (INP). Reducing and delaying scripts is the fix, and it is felt on every page.

• 200 milliseconds or less is Google's threshold for a good INP.
• 7% more sales followed redBus's work on responsiveness.
• The usual cause is script from chat, tracking, sliders and page builders.
• Mid-range phones suffer most, and they are what most customers carry.

What does slow to respond mean?

A page is slow to respond when there is a visible delay between a visitor's action, such as a tap, click or key press, and the screen showing any reaction.

Interaction to Next Paint measures that delay across a whole visit and reports one of the slowest interactions. A result of 200 milliseconds or less is good. Above 500 milliseconds is poor. INP became a Core Web Vital in March 2024, replacing an earlier measure that only looked at the first interaction.

• How website speed affects customer experience and conversions
• Core Web Vitals for business websites

Why does responsiveness matter to customers?

Responsiveness matters because it is what makes a visitor feel in control. The Nielsen Norman Group puts 0.1 seconds as the limit for an action to feel instant. A tap that takes half a second to register breaks that, and the natural reaction is to tap again, which often triggers the action twice.

The bus ticketing site redBus reported that improving INP increased its sales by about 7%. The work targeted the search and booking steps, where customers interact most.

• Perceived vs actual website speed: which one matters?

What makes a site slow to respond?

A browser can only do one main job at a time. If it is busy running script when the visitor taps, the tap waits. The more script a page runs, and the slower the phone, the longer the wait.

• Third-party scripts: chat, adverts, tracking and review widgets.
• Page builders and themes that load large script bundles.
• Sliders and animation libraries running continuously.
• Very long pages with thousands of elements.
• Handlers that do heavy work before showing any feedback.

• Third-party scripts: the hidden reason your site is slow
• Tracking tags and pixels: how marketing slows your site
• Does a live chat widget slow down your website?

How do you make a site respond faster?

Give the browser less to do, and make it show feedback before it does the rest.

• 1. Remove scripts that are not used.
• 2. Delay non-essential scripts until after the page is usable.
• 3. Show an immediate visual change on every tap.
• 4. Break up long script tasks so taps can be handled in between.
• 5. Simplify very long or deeply nested pages.
• 6. Test on a mid-range Android phone, not a new flagship.

• Website animations: when motion makes a site feel slow
• Which devices should you test your website on?

When is a rebuild the only fix?

A rebuild becomes the realistic fix when the delay comes from the platform itself. Some page builders and themes ship so much script that no amount of tuning brings response times into the good range. Diagnose before deciding. If removing third-party scripts on a test copy does not help, the theme or builder is the likely cause.

• Is your page builder slowing your website down?
• Slow website: fix it or rebuild it?

What does this look like in practice?

A pattern we see on sites that pass their loading tests: the page appears quickly, and for the next three seconds the menu button does nothing, because chat, a slider and several tags are all starting up. Visitors tap twice, the menu opens and closes, and they conclude the site is faulty.

Delaying those scripts until the page is idle gives the first taps a clear run. Global Bridge Labs (GBL) tests the first tap on every key page for this reason.

• See client work
• Website Design & Development for UK businesses

Responsiveness checklist

• Tap the menu the moment each key page appears.
• Check INP in PageSpeed Insights field data.
• List scripts that start during the first few seconds.
• Delay or remove the non-essential ones.
• Add a pressed state to every button.
• Re-test on a mid-range phone.

• The website speed scorecard: score your site in an hour
• How to test website speed the way customers feel it

Next step

A site that answers every tap at once feels fast even on a slow connection. We will test yours on an ordinary phone and find what is holding it up.