Core Web Vitals Thresholds (February 2026)
Current Metrics
| Metric |
Good |
Needs Improvement |
Poor |
| LCP (Largest Contentful Paint) |
≤2.5s |
2.5s–4.0s |
>4.0s |
| INP (Interaction to Next Paint) |
≤200ms |
200ms–500ms |
>500ms |
| CLS (Cumulative Layout Shift) |
≤0.1 |
0.1–0.25 |
>0.25 |
Key Facts
- INP replaced FID (First Input Delay) on March 12, 2024. FID was fully removed from all Chrome tools (CrUX API, PageSpeed Insights, Lighthouse) on September 9, 2024. INP is the sole interactivity metric.
- Evaluation uses the 75th percentile of real user data (field data from CrUX).
- Google assesses at the page level and the origin level.
- Core Web Vitals are a tiebreaker ranking signal — they matter most when content quality is similar between competitors.
- Thresholds unchanged since original definitions — ignore claims of "tightened thresholds" from SEO blogs.
- December 2025 core update appeared to weight mobile CWV more heavily.
- As of October 2025: 57.1% desktop sites and 49.7% mobile sites pass all three CWV.
LCP Subparts (February 2025 CrUX Addition)
LCP can now be broken into diagnostic subparts:
| Subpart |
What It Measures |
Target |
| TTFB |
Time to First Byte (server response) |
<800ms |
| Resource Load Delay |
Time from TTFB to resource request start |
Minimize |
| Resource Load Time |
Time to download the LCP resource |
Depends on size |
| Element Render Delay |
Time from resource loaded to rendered |
Minimize |
Total LCP = TTFB + Resource Load Delay + Resource Load Time + Element Render Delay
Use this breakdown to identify which phase is causing LCP issues.
Soft Navigations API (Experimental)
Chrome 139+ Origin Trial (July 2025) — First step toward measuring CWV in SPAs.
- Addresses the long-standing SPA measurement blind spot
- Currently experimental, no ranking impact yet
- Detects "soft navigations" (URL changes without full page load)
- May affect future SPA CWV measurement
Detection: Check for SPA frameworks (React, Vue, Angular, Svelte) and warn about current CWV measurement limitations.
Measurement Sources
Field Data (Real Users)
- Chrome User Experience Report (CrUX)
- PageSpeed Insights (uses CrUX data)
- Search Console Core Web Vitals report
Lab Data (Simulated)
- Lighthouse
- WebPageTest
- Chrome DevTools
Field data is what Google uses for ranking. Lab data is useful for debugging.
Common Bottlenecks
LCP (Largest Contentful Paint)
- Unoptimized hero images (compress, use WebP/AVIF, add preload)
- Render-blocking CSS/JS (defer, async, critical CSS inlining)
- Slow server response (TTFB >200ms — use edge CDN, caching)
- Third-party script blocking (defer analytics, chat widgets)
- Web font loading delay (use font-display: swap + preload)
INP (Interaction to Next Paint)
- Long JavaScript tasks on main thread (break into smaller tasks <50ms)
- Heavy event handlers (debounce, use requestAnimationFrame)
- Excessive DOM size (>1,500 elements is concerning)
- Third-party scripts hijacking main thread
- Synchronous XHR or localStorage operations
- Layout thrashing (multiple forced reflows)
CLS (Cumulative Layout Shift)
- Images/iframes without width/height dimensions
- Dynamically injected content above existing content
- Web fonts causing layout shift (use font-display: swap + preload)
- Ads/embeds without reserved space
- Late-loading content pushing down the page
Optimization Priority
- LCP — Most impactful for perceived performance
- CLS — Most common issue affecting user experience
- INP — Matters most for interactive applications
Tools
# PageSpeed Insights API
curl "https://www.googleapis.com/pagespeedonline/v5/runPagespeed?url=URL&key=API_KEY"
# Lighthouse CLI
npx lighthouse URL --output json --output-path report.json
Performance Tooling Updates (2025)
- Lighthouse 13.0 (October 2025): Major audit restructuring with reorganized performance categories and updated scoring weights. Lighthouse is a lab tool (simulated conditions) — always cross-reference with CrUX field data for real-world performance.
- CrUX Vis replaced the CrUX Dashboard (November 2025). The old Looker Studio dashboard was deprecated. Use CrUX Vis or the CrUX API directly.
- LCP subparts added to CrUX (February 2025): Time to First Byte (TTFB), resource load delay, resource load time, and element render delay are now available as sub-components of LCP in CrUX data.
- Google Search Console 2025 features (December 2025): AI-powered configuration for automated analysis. Branded vs. non-branded queries filter. Hourly data available in API. Custom chart annotations. Social channels tracking.
Mobile-first indexing is 100% complete as of July 5, 2024. Google now crawls and indexes ALL websites exclusively with the mobile Googlebot user-agent. Ensure your mobile version contains all critical content, structured data, and meta tags.
1---2name: core-web-vitals-thresholds-february-20263description: Use this breakdown to identify which phase is causing LCP issues.4---5<!-- Updated: 2026-02-07 -->6# Core Web Vitals Thresholds (February 2026)78## Current Metrics910| Metric | Good | Needs Improvement | Poor |11|--------|------|-------------------|------|12| LCP (Largest Contentful Paint) | ≤2.5s | 2.5s–4.0s | >4.0s |13| INP (Interaction to Next Paint) | ≤200ms | 200ms–500ms | >500ms |14| CLS (Cumulative Layout Shift) | ≤0.1 | 0.1–0.25 | >0.25 |1516## Key Facts17- INP replaced FID (First Input Delay) on **March 12, 2024**. FID was fully removed from all Chrome tools (CrUX API, PageSpeed Insights, Lighthouse) on **September 9, 2024**. INP is the sole interactivity metric.18- Evaluation uses the **75th percentile** of real user data (field data from CrUX).19- Google assesses at the **page level** and the **origin level**.20- Core Web Vitals are a **tiebreaker** ranking signal — they matter most when content quality is similar between competitors.21- **Thresholds unchanged since original definitions** — ignore claims of "tightened thresholds" from SEO blogs.22- December 2025 core update appeared to weight **mobile CWV more heavily**.23- As of October 2025: **57.1%** desktop sites and **49.7%** mobile sites pass all three CWV.2425## LCP Subparts (February 2025 CrUX Addition)2627LCP can now be broken into diagnostic subparts:2829| Subpart | What It Measures | Target |30|---------|------------------|--------|31| **TTFB** | Time to First Byte (server response) | <800ms |32| **Resource Load Delay** | Time from TTFB to resource request start | Minimize |33| **Resource Load Time** | Time to download the LCP resource | Depends on size |34| **Element Render Delay** | Time from resource loaded to rendered | Minimize |3536**Total LCP = TTFB + Resource Load Delay + Resource Load Time + Element Render Delay**3738Use this breakdown to identify which phase is causing LCP issues.3940## Soft Navigations API (Experimental)4142**Chrome 139+ Origin Trial (July 2025)** — First step toward measuring CWV in SPAs.4344- Addresses the long-standing SPA measurement blind spot45- Currently experimental, **no ranking impact yet**46- Detects "soft navigations" (URL changes without full page load)47- May affect future SPA CWV measurement4849**Detection:** Check for SPA frameworks (React, Vue, Angular, Svelte) and warn about current CWV measurement limitations.5051## Measurement Sources5253### Field Data (Real Users)54- Chrome User Experience Report (CrUX)55- PageSpeed Insights (uses CrUX data)56- Search Console Core Web Vitals report5758### Lab Data (Simulated)59- Lighthouse60- WebPageTest61- Chrome DevTools6263> Field data is what Google uses for ranking. Lab data is useful for debugging.6465## Common Bottlenecks6667### LCP (Largest Contentful Paint)68- Unoptimized hero images (compress, use WebP/AVIF, add preload)69- Render-blocking CSS/JS (defer, async, critical CSS inlining)70- Slow server response (TTFB >200ms — use edge CDN, caching)71- Third-party script blocking (defer analytics, chat widgets)72- Web font loading delay (use font-display: swap + preload)7374### INP (Interaction to Next Paint)75- Long JavaScript tasks on main thread (break into smaller tasks <50ms)76- Heavy event handlers (debounce, use requestAnimationFrame)77- Excessive DOM size (>1,500 elements is concerning)78- Third-party scripts hijacking main thread79- Synchronous XHR or localStorage operations80- Layout thrashing (multiple forced reflows)8182### CLS (Cumulative Layout Shift)83- Images/iframes without width/height dimensions84- Dynamically injected content above existing content85- Web fonts causing layout shift (use font-display: swap + preload)86- Ads/embeds without reserved space87- Late-loading content pushing down the page8889## Optimization Priority90911. **LCP** — Most impactful for perceived performance922. **CLS** — Most common issue affecting user experience933. **INP** — Matters most for interactive applications9495## Tools9697```bash98# PageSpeed Insights API99curl "https://www.googleapis.com/pagespeedonline/v5/runPagespeed?url=URL&key=API_KEY"100101# Lighthouse CLI102npx lighthouse URL --output json --output-path report.json103```104105## Performance Tooling Updates (2025)106107- **Lighthouse 13.0** (October 2025): Major audit restructuring with reorganized performance categories and updated scoring weights. Lighthouse is a lab tool (simulated conditions) — always cross-reference with CrUX field data for real-world performance.108- **CrUX Vis** replaced the CrUX Dashboard (November 2025). The old Looker Studio dashboard was deprecated. Use [CrUX Vis](https://cruxvis.withgoogle.com) or the CrUX API directly.109- **LCP subparts** added to CrUX (February 2025): Time to First Byte (TTFB), resource load delay, resource load time, and element render delay are now available as sub-components of LCP in CrUX data.110- **Google Search Console 2025 features** (December 2025): AI-powered configuration for automated analysis. Branded vs. non-branded queries filter. Hourly data available in API. Custom chart annotations. Social channels tracking.111112> **Mobile-first indexing** is 100% complete as of July 5, 2024. Google now crawls and indexes ALL websites exclusively with the mobile Googlebot user-agent. Ensure your mobile version contains all critical content, structured data, and meta tags.
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