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Answer: INP watches how long every interaction on a page takes to produce visual feedback, then reports one number that all, or nearly all, of those interactions stayed under. A low INP means the page answered almost every click, tap, or key press quickly. (S1)

What it measures

• A responsive page is one that reacts quickly when the user interacts with it. (S1)
• INP does not try to capture every downstream effect of an interaction; it measures how long the next paint is held up. (S1)
• According to Chrome usage data, about 90% of the time people spend on a page comes after it has loaded, so responsiveness after load matters. (S1)

Target

• Aim for an INP of 200 milliseconds or less. (S2)
• Judge that target at the 75th percentile of page loads, with mobile and desktop measured separately. (S2)
• Collect field data first so you know whether your INP is poor or needs improvement before trying to fix it. (S2)

Claims

• id: C1 claim: INP reports one value covering nearly all interactions. source: S1 evidence: "and reports a single value which all (or nearly all) interactions were beneath."
• id: C2 claim: INP measures how long the next paint is blocked. source: S1 evidence: "but the time that the next paint is being blocked."
• id: C3 claim: Good INP is 200 ms or less. source: S2 evidence: "websites should strive to have an Interaction to Next Paint of 200 milliseconds or less."
• id: C4 claim: Measure at the 75th percentile. source: S2 evidence: "a good threshold to measure is the 75th percentile of page loads"

Sources

• [S1] Interaction to Next Paint (INP)  |  web.dev. Google (web.dev). https://web.dev/articles/inp . License: CC BY 4.0 (web.dev live page footer: 'the content of this page is licensed under the Creative Commons Attribution 4.0 License'; cite the page, not the archived repo). Accessed 2026-11-05.
• [S2] Optimize Interaction to Next Paint  |  web.dev. Google (web.dev). https://web.dev/articles/optimize-inp . License: CC BY 4.0 (web.dev live page footer: 'the content of this page is licensed under the Creative Commons Attribution 4.0 License'; cite the page, not the archived repo). Accessed 2026-11-05.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).

@misc{iil_note_q6xtgs6w,
  author = {{iinventedlight}},
  title = {{Interaction to Next Paint (INP)}},
  howpublished = {iinventedlight Library},
  year = {2026},
  date = {2026-11-04},
  url = {https://iinventedlight.com/library/notes/webdev-inp/},
  note = {Permanent ID iil:note:q6xtgs6w. License: CC-BY-4.0.},
}

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