Free INP check after a click: Milten analyzes Interaction to Next Paint, finds slow handlers, long animation frames, and third-party scripts that delay interface response.
How it works
How Milten checks INP
From URL to engineering tasks: the service replays important page actions, measures delay until next paint, and shows the technical causes of poor responsiveness.
01 · URL
Enter a URL with important actions
Check a form, catalog, cart, checkout, menu, or account area. Milten opens the page in a browser and applies the selected region, network, and device.
SSLhttps://your-site.com
What INP is
INP is the pause between an action and the visible page response
The metric is not about how fast the page loaded, but how fast it responded after a click, tap, or input. That makes INP especially important for forms, filters, carts, menus, search, and account areas.
Interaction example
How one click becomes INP
The browser has to receive the event, run the handler, recalculate the interface, and show the next frame. INP measures this whole path.
Event breakdown
example INP386ms
click · user pressed a buttonnext paint · interface showed a response
FAQ
Frequently asked questions about INP checks
Short answers about Interaction to Next Paint, Core Web Vitals, SEO, and practical interface optimization.
What is INP and why does it matter?
INP is the Core Web Vitals metric for interface responsiveness. It shows how much time passes between a user action and the page's next visual response. A good value is up to 200ms at the 75th percentile.
How can I check my website INP for free?
02 · SCENARIO
We check interactive scenarios
Clicks, taps, and input that create noticeable delay appear in the report: input delay, synchronous JavaScript, layout/render, and the next paint.
Analysis42%
03 · PLAN
Get causes and a fix order
The report groups issues by impact: what will make the interface respond quickly, where a handler refactor is needed, and what can stay in the performance backlog.
64
Split the checkout handlerP1
Show feedback before calculationsP2
Isolate the chat widgetP3
Input delay
58ms
the event waits for the main thread
JS handler178msvalidation, state recalculation, synchronous logic
Layout / render83msthe browser recalculates DOM and styles
Next paint67msthe new frame finally reaches the screen
0ms58ms236ms319ms386ms
Paste the URL into the form above, choose a mobile or desktop profile, and click “Check INP”. Milten opens the page in a browser, checks interactive scenarios, and shows delays, long animation frames, and initial recommendations.
How is INP different from TBT?
TBT is a lab signal for main-thread blocking during loading. INP evaluates real user interactions after the page has loaded: clicks, taps, input, and the next paint.
What should I do with poor INP?
First find the specific interaction with the highest contribution: a button, filter, form, menu, or checkout. Then check long tasks, synchronous handlers, unnecessary render work, forced reflow, and third-party scripts.
How long does INP analysis take?
A quick check usually takes less than a minute, but exact timing depends on the selected region, network profile, CPU throttling, and number of interactive scenarios. For stable conclusions, compare several runs under the same conditions.