Seuil analysisThis is a reporting cleanup, not a production incident. The useful work is to find slow clicks, taps and keystrokes across real journeys, not to replace one acronym in a slide.
Vercel ends new FID collection on November 1
Vercel announced the Speed Insights change on October 1, 2026. New First Input Delay measurements stop on November 1. The company says no user action is required, existing FID measurements remain viewable and its Real Experience Score is unaffected because it already uses INP.
There is no announced breaking API or application change in that notice. A team with a production storefront on Vercel does not need to redeploy simply because collection stops. The immediate surface to inspect is reporting: dashboards, alerts, recurring decks and internal targets that still name FID.
INP measures more of the visit than FID
FID observed the delay before the browser began handling the first interaction. INP observes clicks, taps and keyboard interactions throughout a visit, then reports a representative worst result. Google replaced FID with INP as a Core Web Vital on March 12, 2024.
That difference matters on an interface that feels fast at entry but becomes sluggish later. A product filter may open instantly, while adding an item, changing quantity or submitting checkout stalls after more JavaScript and data have loaded. FID can miss that journey; INP is designed to capture it.
| Metric | What it observes | Useful product question |
|---|---|---|
| FID | Input delay for the first interaction | Did the browser start responding promptly at first contact? |
| INP | Latency of interactions across the page visit | Did the interface keep responding as the person completed the journey? |
The score stays, but your performance conversation should change
Vercel's current Speed Insights metrics documentation says Real Experience Score uses field data collected from actual visits. INP carries 30 percent of that score, alongside First Contentful Paint, Largest Contentful Paint and Cumulative Layout Shift. Vercel labels 200 milliseconds or less as good INP.
A single site-wide number is still not a diagnosis. If a product dashboard reports weak INP, separate routes and interactions. Opening a menu, applying a filter and saving a form create different main-thread work and require different fixes.
Google's Core Web Vitals guidance also treats INP as the responsiveness measure and recommends checking field data in Search Console. Use that view for broader URL patterns, then use your own real-user monitoring to connect slow results to an interaction.
A slow interaction needs context before a fix
Imagine a hypothetical travel platform where the search page has acceptable INP until a visitor selects four filters. The next filter click waits while a large results list rerenders. Removing animation may make the interface look quieter, but it will not solve unnecessary rendering work.
The web.dev INP guidance explains that field measurement can identify which element a person interacted with, while CrUX data is aggregated and does not reveal the cause. Capture interaction context, route, device class and deployed version where privacy and your data policy allow it.
This is the product-design part of performance work. The team needs to know whether the response appeared, whether feedback was visible and whether the person could continue. A technically recorded interaction can still feel broken when the interface gives no sign that work started.
Update reports before November, not the application
First, find every active report that uses FID and replace the current target with INP. Keep a labelled historical snapshot if the old baseline matters, but do not splice FID and INP into one trend line. They measure different portions of the experience.
Next, choose the three interactions most connected to user value. For a commerce site, those might be product filtering, adding to cart and payment submission. Review their field results and reproduce weak cases on representative devices before changing code.
Finally, assign an owner and a release check. A technical SEO audit can reveal measurement, rendering and delivery issues, while a redesign strategy should protect critical journeys when components or data flows change.
Vercel has not announced an end date for historical FID views
The October 1 notice says existing FID data will remain viewable. It does not state a retention period or promise a permanent historical interface. Teams that need an audit record should document the relevant baseline and its date before collection ends.
The announcement also does not prove that a good INP score makes every interaction usable, accessible or correct. Field metrics are evidence, not a verdict. Keyboard behavior, focus, error recovery and task completion still need direct checks.
Speed Insights FID deprecation checklist
If your dashboard shows weak responsiveness but not the interaction causing it, send the route and user journey to Seuil Digital. The useful next step is a focused INP review, not a generic performance makeover.
- Find dashboards, alerts and reports that still use FID.
- Label any preserved FID baseline with its date and metric definition.
- Use INP for current interaction responsiveness.
- Segment weak results by route, interaction and device context.
- Test the highest-value clicks, taps and keystrokes directly.
- Assign a product and engineering owner for the next review.