Did the web actually get faster?

The spliced headline

The raw fact is real: CrUX's headline share of origins passing Core Web Vitals rose from 43.0% in January 2023 to 55.9% in May 2026. The trap is reading that +12.9-point jump as one measurement, because in March 2024 Google replaced First Input Delay (FID) with Interaction to Next Paint (INP) as the responsiveness vital. The start of that span is on the FID basis and the end is on the INP basis: it is a splice, not a series.

INP is the stricter bar. CrUX published both headlines for seven consecutive months, August 2023 through February 2024, and the INP figure was lower every single time — by 3.2 to 3.7 points (mean 3.5), the gap narrowing as INP pass rates rose. All seven pairs are in the CSV below.

That fixes the direction. Because INP scores lower at the same date, putting the whole span on one metric raises the measured gain rather than shrinking it. From the earliest month CrUX published an INP substitution — 41.6% in August 2023 — to May 2026 the like-for-like move is +14.3 points, against +10.6 for the official headline over that identical span. Three other comparisons are worth having straight, and they are not interchangeable:

• +12.9 pp — the quoted headline, Jan 2023 → May 2026. Spliced across two metrics.
• +14.3 pp — like-for-like on INP, Aug 2023 → May 2026. No estimation needed; both endpoints published.
• +9.1 pp — the official INP era only, Mar 2024 (46.8%) → May 2026.
• +10.1 pp — Jan 2024's INP substitution (45.8%) → May 2026. This is the window the origin panel below covers, so it is the figure the decomposition targets.

What we cannot do is convert January 2023 itself to an INP basis: CrUX published no INP substitution before August 2023, and the seven observed gaps are aggregate, not a per-origin conversion factor. So there is no single “corrected 2023–2026 number,” and any source offering one is estimating.

Two narratives die here. The web did not “get faster because INP replaced FID” — the switch lowered the reported pass rate. But the climb since the switch is far too big to wave away as just the transition: the official INP era alone runs +9.1 points (46.8% in March 2024 to 55.9%). The real, unresolved question is how to split a gain of that size between four very different forces — and the answer is not visible in any trend chart.

The documented shocks — and what's actually moving

Google's own CrUX release notes and Chromium changelogs date the discontinuities. Several explicitly are not ordinary site optimization. The component view shows where the headline comes from: LCP is the main mover (≈ +6 points), with CLS and INP improving from already-high bases.

The events sort into families: metric-definition (FID→INP; the August 2024 scroll exclusion; the June 2024 modal-dialog timing change), browser-side (Chrome scheduler and Android cookie-caching gains; bfcache fixes; a March 2026 Android flagship boost Google measured at 4–6% faster loads), data-quality / coverage (the 2025 Android issue and fix; the ECT→RTT coverage change), and genuine site/platform work (WordPress LCP-image improvements; Google Publisher Tag and consent-platform yielding; Duda removing Cache-Control: no-store on ~40,000 origins).

What it means for performance teams

The decomposition isn't academic — it changes what you do:

• Don't lower your budget on a YoY win. If much of an improvement is metric or browser change, your site didn't actually get faster — cutting the performance budget banks a gain you never made.
• Govern platform defaults, not just pages. If gains concentrate in WordPress, GPT or Duda defaults, the lever is vendor/default governance, not another one-off audit.
• Check bfcache before another image sprint. If browser navigation-cache fixes explain a chunk, removing bfcache blockers (no-store, unload) is higher-return than re-compressing images.
• Label composition on dashboards. If origin churn explains movement, a public “web got faster” chart should say so rather than celebrating optimization that didn't happen.

And it reframes the speed-vs-revenue question our sister study “The cost of a millisecond” tackles: if your CrUX improved but the cause was a browser change, don't expect the conversion lift a real site optimization would have bought.

Data, code & sources

The reproducibility pack is published under CC BY 4.0: the source-coded headline series, the dated event ledger, the window accounting, the BigQuery extraction (panel, constant-origin panel, exposure features and a CSV export step), and an R/fixest event-study skeleton that runs the three exposure-gradient models. Be clear about what that is and isn't: it is the extraction and the event-study layer. The balanced-panel runs, the technology strata and the additive/Shapley allocation described above are specified here but not implemented in the shipped code — you would write them.

Key sources

• Chrome UX Report. Release notes, methodology & CrUX on BigQuery.
• Pollard, B. & Henkel, J. (2025). LCP image subparts and RTT now available in CrUX. Chrome for Developers.
• Chromium (2024). INP changes in Chrome 128 (scroll-starting exclusion).
• Chromium (2025). Cross-origin LCP renderTime change — “did not affect CrUX” (the negative control).
• Pollard, B. & Wagner, J. (2025). Time to First Byte. web.dev (Early Hints; Chrome 133 responseStart revert).
• Seckler, E. (2026). Android Sets New Record for Mobile Web Performance. Google Chromium Blog.
• Jariyal, H. et al. (2026). Performance. The Web Almanac 2025, HTTP Archive.

Cite this study

PageSpeedAudit Research (2026). Did the web actually get faster? A causal
decomposition framework for 2023-2026 Core Web Vitals improvement.
https://pagespeedaudit.com/research/did-the-web-get-faster

@misc{pagespeedaudit2026webfaster,
  title  = {Did the web actually get faster? A causal decomposition framework
            for 2023-2026 Core Web Vitals improvement},
  author = {{PageSpeedAudit Research}},
  year   = {2026},
  url    = {https://pagespeedaudit.com/research/did-the-web-get-faster},
  note   = {Headline series + event ledger + BigQuery/R code, CC BY 4.0}
}