Free website speed test with Core Web Vitals
Find out how fast your site loads on mobile or desktop, which Core Web Vitals need work and which fixes will make the biggest difference. No signup needed for a single audit.
What it checks
Everything the website speed test looks at
Lighthouse performance score
A 0-100 score from Google PageSpeed Insights that summarises how quickly your page loads and becomes usable.
Largest Contentful Paint (LCP)
Measures how long the main content takes to appear, which is what visitors judge your speed on.
Cumulative Layout Shift (CLS)
Shows how much the page jumps around while loading, a common cause of mis-taps and frustration.
Total Blocking Time (TBT)
Captures how long scripts block the main thread, a lab indicator of how responsive the page will feel.
First Contentful Paint (FCP)
Records when the first text or image appears so visitors know the page is loading.
Speed Index and Time to Interactive
Additional Lighthouse timings that show how quickly the page fills in visually and becomes fully usable.
Mobile or desktop strategy
Test the way Google tests: mobile with a throttled connection, or desktop for office-based audiences.
Top improvement opportunities
The biggest fixes, ranked by estimated time saved, so you know where to start.
Real-user field data (CrUX)
When Google has enough Chrome user data for your site, we show how real visitors experience it.
How it works
Three steps, about a minute.
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1
Enter your URL
Paste any public web address and choose mobile or desktop.
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2
We run Lighthouse
Your page is tested through Google PageSpeed Insights and the results are scored and explained.
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3
Fix what matters most
Work through the opportunities in order of estimated time saved, then re-test to confirm.
What a website speed test actually measures
A good website speed test does more than time how long a page takes to load. It looks at when the first content appears, when the largest element is visible, how long scripts block interaction and whether the layout shifts as images and adverts arrive. MakeItFlow uses Google PageSpeed Insights, which runs Lighthouse in a controlled lab environment, so you get the same performance score and metrics that Google itself reports. Because lab tests use a fixed device and connection, results are repeatable, which makes them ideal for checking whether a change has helped. Where Google has collected enough Chrome user data for your site, we also show field data, so you can compare the lab picture with what real visitors see.
How to improve your Core Web Vitals score
Most slow sites share a handful of causes: oversized images, render-blocking CSS and JavaScript, slow server response times and third-party scripts such as chat widgets and tag managers. Our report lists the opportunities Lighthouse finds, ordered by the time each one could save, so you can tackle the highest-value fixes first. For LCP, start with the hero image and server response time. For CLS, set width and height on images and reserve space for embeds. For responsiveness, reduce or defer heavy JavaScript. After each change, re-run the speed test on the same strategy to confirm the improvement, and keep in mind that field data in Google Search Console updates over a rolling 28-day window.
Why it matters
Know what to fix first
Opportunities are ranked by the time they save, so you avoid spending a week on a change worth 50 milliseconds.
Lab and field data together
Lab results show what to change today, while real-user data shows how visitors actually experience your site.
Part of a full audit
Performance makes up 30% of your overall A-F grade, alongside SEO, security, email and DNS checks.
Who it is for
Small business owners
Get a plain-English view of whether your site is slow and what to ask your developer to change.
Agencies
Show clients a clear before and after, with a shareable report link and PDF.
Developers
Jump straight to the Lighthouse opportunities and Core Web Vitals that need attention.
Learn more
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WordPress Core Web Vitals: Which Plugins Actually HelpWebsite Speed · 5 min read
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Best Cloudflare Free Plan Settings for a Small Business SiteWebsite Speed · 11 min read
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Core Web Vitals Explained: LCP, INP and CLS ThresholdsWebsite Speed · 12 min read
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PageSpeed Insights Score Explained: Why It Keeps ChangingWebsite Speed · 7 min read
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How to Improve Largest Contentful Paint (LCP), Step by StepWebsite Speed · 8 min read
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How to Eliminate Render-Blocking Resources (CSS, JS and Fonts)Website Speed · 7 min read
Yes. You can run a single audit without signing up, and the free plan includes 5 scans a day. Paid plans add saved sites, scheduled re-scans and more.
Mobile tests simulate a mid-range phone on a slower connection, so heavy pages are penalised more. Most of your visitors are likely on mobile, so it is usually the score to prioritise.
Lighthouse results vary slightly with server load, network conditions and third-party scripts. Small swings of a few points are normal; look for consistent trends rather than a single run.
Lab data comes from a single controlled test and is useful for debugging. Field data comes from real Chrome users over the past 28 days and is what Google uses for its page experience signals.
Free website audit
See how your site scores, free
Speed, SEO, DNS, email (SPF/DKIM/DMARC) and security in one scan, with a prioritised fix list.