INP – New Metric in Core Web Vitals
In 2020, Google introduced Core Web Vitals (LCP, FID, CLS), officially making them ranking metrics affecting search engine rankings in February 2022.
As a next step, in April 2023, Google announced the retirement of several ranking systems (Page experience, Mobile-friendly, Page speed, Secure sites), increasing the impact of Core Web Vitals on rankings.
The Decline of FID
The purpose of the First Input Delay (FID) metric is to measure the interactivity of web pages, specifically the time it takes for the browser to process the first user interaction on a page.
More precisely, FID measures the time elapsed between the first user interaction with the page and the moment when the browser is actually able to begin processing events.
The main limitations of this metric are:
- It considers only the first interaction.
- It captures only four types of events (click, keydown, mousedown, pointerdown).
- It measures only the delay to execution, excluding event handling time.
Due to these limitations, work on a new interactivity metric began in June 2021.
Interaction to Next Paint (INP)
The new metric, INP, measures the delay of all user interactions on a page and returns a single value below which all (or nearly all) interactions fall.
A low INP score indicates that the page was consistently responsive to all or the majority of user interactions.
Evaluating INP Score
- Good INP score: less than 200 milliseconds
- INP score needing improvement: between 200 and 500 milliseconds
- Poor INP score: above 500 milliseconds
Optimizing for INP
Actions that can reduce INP values include:
- Identifying and reducing input delays
- Optimizing event callback handling
- Minimizing display delay
In some tools (e.g., Chrome DevTools and Lighthouse), you may find the Total Blocking Time (TBT) value instead of INP.
When Will INP Replace FID?
From May 2023 to May 2023, INP had an “experimental” status. Currently, it is a “pending” metric, and in March 2024, it will replace FID.
INP in Super Monitoring
Super Monitoring has been offering Core Web Vitals monitoring since May 2021.
Since September 2023, we have been collecting and storing INP values as well.
Exceeding the thresholds (“needing improvement” or “poor”) does not trigger issue recording and alerts yet. This functionality will begin after Google officially introduces the metric in March 2024.
At that time, Super Monitoring will stop collecting and storing FID values.
