Core Web Vitals Checker
Check and understand your Core Web Vitals (LCP, INP, CLS, FCP, TTFB, TBT) with educational guidance and optimization tips.
LCPLargest Contentful Paint
LCP is one of the three Core Web Vitals used by Google as a ranking signal. A fast LCP reassures the...
INPInteraction to Next Paint
INP captures overall page responsiveness, not just the first interaction. Google uses it to ensure p...
CLSCumulative Layout Shift
Unexpected layout shifts frustrate users and can cause mis-clicks. CLS is the third Core Web Vital a...
FCPFirst Contentful Paint
FCP is an important diagnostic metric that complements LCP. A fast FCP provides visual feedback earl...
TTFBTime to First Byte
TTFB is a foundational metric. A slow TTFB delays every subsequent metric (FCP, LCP, etc.) because n...
TBTTotal Blocking Time
TBT is a lab proxy for INP. It helps identify heavy JavaScript execution that makes the page feel un...
Frequently Asked Questions
What is the Core Web Vitals Checker?
The Core Web Vitals Checker is a free online tool that check and understand your core web vitals (lcp, inp, cls, fcp, ttfb, tbt) with educational guidance and optimization tips.. It runs entirely in your browser with no installation or sign-up needed.
Does this measure my site automatically?
No. Enter values from PageSpeed Insights, Lighthouse, or CrUX. The tool evaluates them against Google thresholds with color-coded results and optimization tips.
What are the three Core Web Vitals?
LCP (loading), INP (interactivity, replaced FID in March 2024), and CLS (visual stability). All three must be "Good" to pass Google CWV assessment.
What are the thresholds?
LCP: <2.5s good, >4s poor. INP: <200ms good, >500ms poor. CLS: <0.1 good, >0.25 poor. FCP: <1.8s good, >3s poor. TTFB: <800ms good, >1800ms poor. TBT: <200ms good, >600ms poor.
Is the Core Web Vitals Checker free to use?
Yes, the Core Web Vitals Checker is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.
Is my data safe with this tool?
Absolutely. The Core Web Vitals Checker processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.
Does the Core Web Vitals Checker work on mobile devices?
Yes, the Core Web Vitals Checker is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.
Do I need to create an account to use this tool?
No account or registration is needed. Simply open the Core Web Vitals Checker in your browser and start using it immediately. There are no sign-up walls or usage restrictions.
Does this tool follow Google's latest guidelines?
Yes, the Core Web Vitals Checker is built following current Google Search guidelines and best practices. We regularly update the tool to reflect changes in search engine requirements.
How do I use the Core Web Vitals Checker?
Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.
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About Core Web Vitals Checker
Core Web Vitals Checker is a free, browser-based tool in our SEO Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.