- 1Choose file
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Core Web Vitals Risk Check online, free
Find markup that risks poor LCP, CLS and FCP. It reads the HTML and does not measure the page; use Lighthouse Audit for measured values.
- Runs in your browser — no upload
- Free, no sign-up, no watermark
- HTML
- TXT
How to use Core Web Vitals Risk Check · Core Web Vitals Risk Check — frequently asked questions
How to use Core Web Vitals Risk Check
- 1
Add your HTML and TXT file
Drop a file on the page, paste it, or click Select Files. Nothing is uploaded — it opens straight in your browser.
- 2
Fine-tune the settings
Set device viewport in the Fine-tune panel, or keep the defaults — they suit most files.
- 3
Run Core Web Vitals Risk Check
Press the start button. Processing happens on your device, usually in seconds.
- 4
Download the result
Save the finished file, or continue with another tool without downloading in between.
What Core Web Vitals Risk Check can do
- Device Viewport: mobile and desktop
- Private by design — files are processed in your browser and never uploaded
- Free with no sign-up, no watermark and no daily limit
Common tasks
Core Web Vitals Risk Check — frequently asked questions
What are Core Web Vitals?
Core Web Vitals are a set of specific real-world metrics defined by Google to measure user experience, including loading speed (LCP), visual stability (CLS), and responsiveness (INP).
What is Largest Contentful Paint (LCP)?
LCP measures perceived load speed by identifying when the main content of a webpage has likely loaded. A good LCP score is 2.5 seconds or faster.
What is Cumulative Layout Shift (CLS)?
CLS measures visual stability by tracking unexpected layout shifts during the page lifecycle. A good CLS score is 0.1 or less.
What is Interaction to Next Paint (INP)?
INP assesses overall page responsiveness by measuring latency of user interactions like clicks, taps, and key presses throughout the entire visit. A good INP score is 200 milliseconds or less.
Does this audit run privately?
Yes, this audit executes privately in your browser or against public endpoints with zero user tracking, accounts, or analytics logging.
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