Your site loads slowly and shifts content around while people try to click. Google measures that — and ranks you lower if you fail.
Slow LCP, jumpy CLS, bad INP — they’re not vague warnings. They’re specific scores tied to real ranking drops. You can check them in seconds.
What Is a Core Web Vitals Checker?
Core Web Vitals Checker is a free browser-based tool that tests your page’s LCP (Largest Contentful Paint), CLS (Cumulative Layout Shift), and INP (Interaction to Next Paint). It runs your URL through Google PageSpeed Insights and shows scores for mobile and desktop side by side — no login needed.
The real issue is most people only test one device. Your mobile speed might be trash while your desktop looks fine. This tool forces you to see both.
Why It Matters for SEO
Google uses Core Web Vitals as a ranking signal. Pages with poor INP or LCP get pushed down — especially in mobile search. Sites scoring below 50 on mobile often lose 20-30% of potential traffic compared to faster rivals.
Most people miss that INP replaced First Input Delay (FID) in 2024. If you're still optimizing for FID, you're chasing an old metric. Here's what actually happens: Google records every click, tap, or keystroke. If your page takes over 500ms to respond to one, that counts against you.
Also, layout shifts (CLS) hurt conversions. A score above 0.25 means buttons jump, banners pop in late, and users misclick. That raises bounce rates — Google notices.
How to Use It
- Go to https://scrawl.tools/tools/core-web-vitals (no login needed)
- Enter your full URL — include https://
- Click "Analyze" and wait 30 seconds for results
It’s free. It pulls live data from Google. You can retest as many times as you want.
What the Results Tell You
You’ll see two speed reports: one for mobile, one for desktop. Each shows LCP, CLS, and INP with clear labels — good, needs improvement, or poor.
LCP under 2.5 seconds is safe. Anything over 4 seconds is bad. CLS should be under 0.1 to pass. INP under 200ms is ideal; above 500ms is failing.
The tool also lists specific failures — like slow-loading images or blocking JavaScript. You don’t get vague advice. You get exact file names and suggestions to fix them.
Most people skip the “Opportunities” section. Big mistake. That’s where you find easy wins — like deferring non-critical scripts or compressing a 4MB hero image.
3 Mistakes Most People Make
- Testing only the homepage. Your blog or product pages might be dragging scores down. Check high-traffic pages, not just the front door.
- Ignoring mobile results. Google indexes mobile-first. If your mobile LCP is 5.8 seconds, your whole site suffers — even if desktop looks fine.
- Waiting months to retest. Speed changes daily. A third-party script update or image upload can wreck your CLS. The fix isn’t permanent. Most people test once and walk away. That’s why their scores decay.
Here's what actually happens: Google recrawls most sites every 3-7 days. If you fix a slow script, you’ll see changes in a week — but only if you check.
Check your site now: Core Web Vitals Checker. It's free, no login needed — just results.
