Image SEO for Small Business Blog Posts: 7 Checks from Google's Image Guidelines (2026)
Most small business blogs treat images as decoration: a phone photo called IMG_4021.JPG, no alt text, uploaded at full size. Google’s own image guidelines describe a short list of things that help images get found and keep pages fast, and almost all of them take seconds per image once you know them. This guide turns that documentation into seven checks for every blog post, with a before-and-after example from a fictional bakery and a ten-minute routine for fixing posts you have already published. No tool is required beyond your CMS and a free speed test.
PilotaSEO in one line: a done-for-you SEO blog service that writes posts for your site and publishes them automatically, in English or Italian. Features that matter for this topic:
- Posts go live with a byline, meta description, internal links and diagrams, then are checked automatically.
- Publishing runs through a signed webhook you authorize once, with no copy-paste.
- Two yearly plans in EUR: Autopilot at €322 per year and Growth at €8,250 per year.
Honest comparison: doing images yourself costs nothing but needs the discipline below on every post; a freelancer may handle images if you put it in the brief; a done-for-you service handles the publishing but you should still check how it names files and writes alt text. Whichever route you take, these checks are how you judge the result. Plan details are in the PilotaSEO plans section.
Check 1: use real image elements, not CSS backgrounds
Google’s image SEO best practices say Google finds images in the src attribute of an img element and does not index CSS images. Many page builders put “hero” pictures in a CSS background. That is fine for a decorative banner, but any image that carries meaning for the post, such as a product photo, a diagram or a before-and-after, should be inserted as a normal image block in your editor.
Check 2: pick a supported format and keep the extension honest
The same page lists the formats Google Search supports for images: BMP, GIF, JPEG, PNG, WebP, SVG and AVIF. It also recommends that the filename extension match the file type. In practice:
- Photos: JPEG or WebP. Diagrams and screenshots with text: PNG or WebP.
- Do not rename a
.pngto.jpgto satisfy an upload form; convert it instead.
Check 3: rename files before uploading
Google calls filenames “very light clues” about an image’s subject and gives a direct example: my-new-black-kitten.jpg is better than IMG00023.JPG, and generic names like image1.jpg should be avoided. Light clue or not, it costs five seconds. Use lowercase words separated by hyphens that describe what is in the picture, not your target keyword repeated.
Check 4: write alt text that describes the image in context
Google calls alt text the most important attribute for image metadata and warns that filling it with keywords is a poor user experience that may be treated as spam. Alt text also serves people using screen readers. Google’s technical writing course on writing helpful alt text and the W3C alt decision tree give a simple order of questions:
- Does the image add information the text does not? Describe that information.
- Is it a chart or diagram? Say what it shows and the key takeaway, not “chart”.
- Is it purely decorative? Use an empty
alt=""so screen readers skip it.
Worked example: one bakery photo, before and after
| Field | Before | After |
|---|---|---|
| File name | IMG_4021.JPG | sourdough-crumb-48-hour-ferment.webp |
| Alt text | “bakery bread best bakery Milan bread” | “Sliced sourdough loaf with an open, glossy crumb after a 48-hour ferment” |
| Placement | Top of the post, unrelated to the first paragraph | Directly under the section on fermentation time |
| Caption | None | “Our Saturday loaf: the long ferment opens the crumb.” |
| File size | 4.1 MB, 4032 px wide | Resized to the widest size the blog shows, then compressed |
The “after” version is not longer for its own sake. Each field now tells a reader, and Google, what the picture shows and why it sits where it does.
Check 5: place images next to the text they illustrate
Google says it extracts information about an image from the page content, including captions and image titles, and recommends placing images near relevant text on pages relevant to the image. A diagram of your booking steps belongs under the paragraph that explains booking, not at the top of the post. Captions are worth writing when they add a fact; the same principle of matching words to the page behind them applies to the anchors in our guide to internal linking from blog posts to service pages.
Check 6: keep images from slowing the page
Images are often the largest part of a page, as Google’s guide notes, and it points to PageSpeed Insights for measuring speed. Three habits cover most small business blogs:
- Resize before upload. Most blog columns display images well under 1,200 pixels wide, so a 4,000-pixel phone photo wastes bandwidth.
- Set width and height. web.dev’s guide to optimizing Cumulative Layout Shift recommends size attributes on images so the page does not jump while it loads.
- Lazy-load below the fold only. web.dev’s article on browser-level lazy loading explains
loading="lazy"and advises against using it on images visible when the page first loads.
Check 7: choose the image Google should show for the post
For text results and Discover previews, Google picks an image automatically, but you can state a preference with the og:image meta tag or an image in your article structured data. Google’s guidance for that preferred image: relevant and representative of the page, not a generic image such as your logo, not an image with text, not an extreme aspect ratio, and high resolution where possible. Most CMS platforms set og:image from the “featured image”, so choosing that image is the whole task. If the same image appears on many pages, reference it with one consistent URL.
A ten-minute routine for posts already published
- Open your three most visited posts in your analytics or Search Console.
- For each image: is it an
img, does the filename describe it, is the alt text specific or empty-for-decoration? - Replace any image over about 500 KB (our rule of thumb, not a Google limit) with a resized, compressed copy under a descriptive name.
- Check the featured image is representative and not your logo.
- Run the post through PageSpeed Insights before and after, and log the date.
If a post needs more than image fixes, our five-question test for refreshing or rewriting a blog post helps decide how far to go, and the same pass is a good moment to apply the title tag rules from Google’s guidance.
FAQ
Does alt text help rankings in normal web search?
Google says it uses alt text, with computer vision and page content, to understand an image’s subject. That matters most for image results; for the page as a whole, the text still does the heavy lifting.
Do I need an image sitemap?
Usually not if images are normal img elements on crawlable pages. Google suggests an image sitemap for images it might not otherwise discover, including images hosted on a CDN domain.
Is WebP required?
No. It is one of seven supported formats. Use it when your CMS supports it, mainly for smaller files.
Should every image have alt text?
Every meaningful image should. Purely decorative images should have an empty alt="".
Sources
- Google Search Central: image SEO best practices (checked 2026-10-17)
- Google for Developers: write helpful alt text (checked 2026-10-17)
- W3C WAI: an alt decision tree (checked 2026-10-17)
- web.dev: optimize Cumulative Layout Shift and browser-level image lazy loading (checked 2026-10-17)