Interaction to Next Paint (INP): what a good score is and how to improve it
INP measures how quickly a page responds when a shopper taps or clicks. Google rates 200ms or less as good. See what causes a slow INP and how to fix it.
2 min read
Area
Speed
Severity
High
Fix effort
Large
Stores failing
1%
Of 83 stores we scanned where this check applies, 1% fail it and 66% pass. See all benchmarks.
Interaction to Next Paint (INP) measures the delay between a shopper tapping, clicking or typing and the page visibly responding. Google counts 200 milliseconds or less as good and over 500 milliseconds as poor. It replaced First Input Delay as a Core Web Vital in March 2024.
Why it matters
Every tap on a size selector, filter or add-to-cart button is a promise that something will happen. When the page freezes for half a second, shoppers tap again, tap elsewhere or leave. Stores with many third-party scripts feel this most, because those scripts compete for the same browser thread that handles taps.
INP is measured on real visitors, so you cannot fake it with a lab test.
What the audit looks at
INP can only be reported when Google has enough real-visitor data for the page. When it does, the audit reports it. When it does not, the check does not apply to your store.
What usually causes it
- Heavy JavaScript from apps, chat widgets and tag managers running on the main thread
- Large event handlers on filters, variant pickers or carousels that do too much work per tap
- Layout recalculation after a tap, such as a menu that forces the whole page to reflow
- Low-powered phones, which amplify every one of the above
How to fix it
Reduce the JavaScript work that runs when someone taps. The effort is large, development work that takes a project.
- Record a performance trace while interacting with the page and find the long tasks blocking the main thread.
- The usual cause on a store is third-party scripts -- chat widgets, review apps, personalisation -- each adding listeners to every click.
- Remove apps you no longer use. Every one of them costs interaction speed on every page for every visitor.
- Defer whatever is not needed for the first interaction, and break long tasks so the browser can respond between them.
How to check it yourself
- Run PageSpeed Insights on your product page and look for the INP figure in the field data section at the top.
- In Chrome DevTools, open the Performance panel, record a tap on a variant selector, and look for long tasks over 50 milliseconds.
- Remove one third-party script at a time on a staging copy and measure again to find the worst offender.
Frequently asked questions
Why does my store have no INP score?
Google only reports INP when enough real visitors have interacted with the page over the previous 28 days. Low-traffic stores often have no field data, and that is not a fault.
Is INP the same as First Input Delay?
No. First Input Delay measured only the delay before the first interaction was handled. INP looks at all interactions across the visit and reports a near-worst value.
Related checks
- Largest Contentful Paint (LCP): how to get under 2.5 seconds
- Cumulative Layout Shift (CLS): why your store jumps and how to stop it
- Slow product and collection pages: how to compare templates against the rest of your site
Further reading
Check your own store
See whether your store passes this check
Paste your store URL. The audit loads your pages in a real browser and shows the result for this check with the evidence behind it.