Free Lazy Loading Checker: Find Images Slowing Your Site Down
Scan any page to see which images and iframes load lazily, which do not, and get clear fixes to speed up your site. Results in seconds.
Spot Missing Lazy Loading
See every image and iframe on the page that loads eagerly when it could wait, wasting bandwidth on first load.
Protect Your Core Web Vitals
Lazy loading images near the top of the page can hurt LCP. We flag ones that should load right away.
Get Clear Fix Recommendations
Each finding comes with a plain-language recommendation, including the exact loading attribute to add or remove.
A lazy loading checker inspects which images and iframes on your page defer loading until they near the viewport. You enter a URL and it reports which elements use native lazy loading, which load eagerly, and whether above-the-fold media is wrongly deferred. It helps you balance faster initial loads against content that must appear immediately for users and crawlers.
What the lazy loading checker detects
The checker scans your page for images, iframes, and background media, then records how each one is set to load. It flags elements carrying the loading attribute set to lazy, those left eager, and any relying on script-based lazy loading libraries. It also identifies media positioned above the fold that has been deferred, along with off-screen assets still loading eagerly and consuming bandwidth up front. Where dimensions are missing, it notes the layout shift risk that deferred images can introduce. The result is a clear inventory of what loads immediately versus on demand, so you can spot both wasted requests and harmful delays.
How to fix misconfigured lazy loading
Use the report to correct two opposite mistakes. Media inside the initial viewport, especially your Largest Contentful Paint image, should load eagerly so it renders without delay, so remove lazy loading from those elements. Everything below the fold should defer, so add loading set to lazy to offscreen images and iframes that still load up front. Always pair deferred images with explicit width and height to prevent layout shift as they appear. Prefer the native loading attribute over heavier JavaScript libraries where browser support allows. Recheck after edits to confirm the fold boundary is respected and no critical asset waits behind a scroll.
Why lazy loading affects page speed and SEO
Lazy loading trims the initial payload so pages become interactive sooner, which improves Core Web Vitals and the experience search engines reward. Get it wrong, though, and the effects invert: deferring the hero image inflates Largest Contentful Paint, while eager offscreen media wastes bandwidth and slows everything above it. Improperly deferred content can also be missed if crawlers do not trigger the load. Checking your configuration keeps the speed benefit without sacrificing visibility of important media. Correct lazy loading lowers bounce rates on slow connections and protects the performance scores that underpin technical rankings, making it a small change with outsized impact.
Frequently Asked Questions
What does the Lazy Loading Checker actually check?
It fetches your URL and scans every image and iframe for the loading attribute. You get a list of elements that load lazily, elements that load eagerly, and recommendations on which ones to change for faster page loads.
Does lazy loading really affect SEO?
Yes, indirectly. Lazy loading cuts initial page weight, which improves load speed and Core Web Vitals. Google uses page experience signals in ranking, so faster pages tend to perform better in search and keep visitors around longer.
Is the Lazy Loading Checker free to use?
Yes. Create a free Brainito account and you can run the Lazy Loading Checker on any URL, along with the rest of our SEO tools. There is no credit card required, and each scan finishes in seconds.
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