Blogger Image Lazy Loading for SEO

The short answer: You can still use Blogger image lazy loading for SEO without losing image crawlability, provided the image URL appears in the src attribute of the <img> element in the rendered HTML. Important images near the top of the post should not be deferred; images farther down can use loading="lazy" or automatic loading when they approach the viewport. Then inspect the rendered HTML in Search Console rather than looking only at the initial source code.

The process below is suitable for Blogger authors and requires no server changes. You need permission to edit the post or theme, a desktop browser, and a Google Search Console account with the blog verified. The ultimate goal is for readers to see the post load quickly while Googlebot can still discover the content and image URLs.

Why can Blogger image lazy loading affect SEO?

Lazy loading defers images that are outside the viewport to reduce the number of resources loaded when the page first opens. This technique can help performance, but images should not become content that appears only after an action Googlebot does not perform, such as clicking a button, swiping, or manually scrolling. Google recommends that deferred content appear automatically as it approaches the viewport; Google Search does not interact with pages like a real user (according to Google Search Central).

The issue is usually not the keyword or file name, but how the image URL is placed in the HTML. If the image element contains only a placeholder in src, while the real URL is hidden in a custom attribute such as data-src and JavaScript replaces it only after the user scrolls, Google may not process the image reliably. Conversely, Google may find images in the src attribute of the <img>element, even when that element is inside a <picture> structure (according to Google Search Central).

Guidelines for classifying images before optimization

Image type	Recommended loading method	Reason
Featured or primary image at the top of the post	Load normally, without lazy loading	This is content that readers and search engines need to see early.
Illustrative image immediately after the introduction	Consider normal loading if it is near the viewport	Avoid delaying the image when readers have just opened the post.
Illustrative image in the middle or at the end of the post	Use `loading="lazy"`	This reduces the initial load while allowing the browser to load the image automatically as it approaches the viewport.
CSS background image	Do not use for images that need to be indexed	Google recommends using an HTML `<img>`element; CSS images are not a suitable choice for discovery in Google Images.

Do not add lazy loading to every image mechanically. Google also warns that deferring content likely to be visible when the page opens can make the initial experience slower (according to Google Search Central).

How to implement Blogger image lazy loading safely for SEO

Step 1: Insert images using an HTML element with the real URL

In the Blogger editor, switch to the post's HTML view and inspect each image. A basic structure should include the real URL in src, alternative text in alt, and the expected dimensions using width and height if you know the exact image ratio:

<img src="https://blogger.googleusercontent.com/img/b/example-image.webp"
     alt="Ảnh minh họa cách tối ưu ảnh Blogger"
     width="1200"
     height="675"
     loading="lazy"
     decoding="async">

For the first or primary image in the post, remove loading="lazy" if the image appears in the first viewport. For images farther down the page, keeping this attribute is simpler than writing custom JavaScript.

The URL in the example is for illustration only. When publishing, you must use the actual image URL generated by Blogger. Do not replace the real URL with a placeholder such as a transparent 1×1-pixel image, because Google may see only the placeholder instead of the content you want indexed.

Step 2: Write alt text and file names for both SEO and accessibility

The alt attribute should accurately describe the image's content or function, not serve as a keyword list. For example, alt="Kiểm tra thuộc tính src của ảnh trong HTML Blogger" is more useful than alt="Blogger lazy loading ảnh SEO ảnh Blogger Google SEO". Google uses alt text together with page content and image-recognition systems to understand an image’s subject; keyword stuffing can degrade the user experience and be considered inappropriate behavior (according to Google Search Central).

Place images near the relevant paragraphs, use descriptive filenames where possible, and keep a stable URL for the same image across pages. Reusing the same URL allows Google to cache the resource and avoids requesting the same asset unnecessarily often (according to Google Search Central).

Step 3: Optimize dimensions without removing the fallback URL

Large images are a common reason Blogger posts become heavy. Export images at the closest practical display size, compress them before uploading, and prioritize modern formats such as WebP or AVIF when your workflow supports them. If you use srcset to serve different screen sizes, you must still keep src as the fallback URL:

<img src="anh-800.webp"
     srcset="anh-480.webp 480w, anh-800.webp 800w, anh-1200.webp 1200w"
     sizes="(max-width: 600px) 100vw, 800px"
     alt="Ảnh minh họa tối ưu ảnh Blogger"
     loading="lazy">

Google recommends always providing a URL in src when using srcset, because not every browser or crawler handles responsive-image attributes in the same way (according to Google Search Central).

Check Images in the HTML and Confirm That Googlebot Loads Them

Quick Browser Check

Open the published post in an incognito window.
Right-click, select Inspect , then find the <img>tag.
Confirm that important images have a real URL in src, not just data-src.
Scroll slowly to the end of the post and check whether the images appear automatically without requiring a button click.
In the Network tab, filter by Img to verify that image URLs return successfully, without 403 or 404 errors or unusual redirects.

Do not check only View page source. If the interface or JavaScript changes the HTML after loading, the initial source may differ from the HTML visible to the browser and Google.

Check Using Search Console

Open the URL Inspection tool in Google Search Console.
Paste the post URL and choose to inspect the published version.
If necessary, select Test Live URL, then open the crawled-page view or rendered HTML section.
Find the <img> tags and confirm that important images still have a URL in src.
Also check resource accessibility: images must not require sign-in, be blocked by robots.txt, or return server errors.

Google recommends using URL Inspection to confirm that lazy-loaded content appears in the rendered HTML; if the image URL is in the src of the <img>tag, that indicates the implementation is working correctly at a basic level (according to Google Search Central).

You can also use the Blogger Help to review additional theme settings that may affect speed and crawlability. If interaction performance is affected after adding a script, measure it again with PageSpeed Insights and DevTools rather than relying solely on subjective impressions.

Common Errors and Fixes

Image exists only in data-src: move the actual URL to src or replace the JavaScript mechanism with the browser’s loading="lazy" .
The first image appears late: disable lazy loading for the main image and recheck its dimensions, format, and delivery server.
Image returns a 404 or 403 error: Open the image URL directly, check its access permissions, and replace the broken link.
Images blocked by robots.txt: Only block decorative resources that are not needed to understand the content; do not block directories containing images that need to be indexed.
Overly complex lazy-loading script: Revert to standard HTML, reduce reliance on JavaScript, and then check the rendered HTML again.

Lazy loading does not guarantee that images will rank in Google Images. It only lets you defer image loading while preserving discoverability, provided that the HTML, URL, alt text, accessibility, and page quality are all appropriate. After making changes, request that Google recrawl the URL; crawling and indexing do not happen immediately.

Completion checklist: The lead image is not deferred; images farther down the page load automatically as they approach the viewport; every image that needs to be SEO-friendly has a src real source URL; natural, descriptive alt text; is not blocked by robots.txt; appears correctly in the rendered HTML in Search Console; and the page still achieves acceptable performance on mobile devices.

Reference source

Fix Lazy-Loaded Website Content — Google Search Central
Google Image SEO Best Practices — Google Search Central
Troubleshoot Google Search Crawling Errors — Google Search Central
Prepare for mobile-first indexing — Google Search Central Blog

Blogger Image Lazy Loading for SEO: Crawlable Pages