Image SEO that fills the gaps for you.

Why images need SEO

Images do two jobs on a web page. They help people understand and enjoy your content, and they're a source of traffic in their own right through Google Images and the image results that appear in regular search. Neither job works well if the image can't be described.

Search engines can analyse what's in a picture, but they still rely heavily on text around it: the alt text, the file name, the caption and the content nearby. Screen readers rely entirely on alt text to describe images to people who can't see them. An image without alt text is invisible to both.

Yet missing alt text is one of the most common problems on WordPress sites. Images get uploaded in a hurry, imported from old sites or added by people who don't know the field exists. Rilea SEO's image SEO tools close that gap automatically, while leaving you in charge of the alt text that matters most.

What alt text is for

Alt text, short for alternative text, is a short written description of an image, stored in the image's alt attribute. It has three uses:

• Accessibility. Screen readers read it aloud, so people with visual impairments know what the image shows.
• Search. Search engines use it to understand the image and the page, and to decide when to show the image in image search.
• Fallback. If the image fails to load, browsers show the alt text in its place.

Good alt text describes what the image shows, in a way that makes sense in context. "Woman tying the laces of a blue trail running shoe on a rocky path" is useful. "Image1" or "shoes shoes running shoes best shoes" is not.

How Rilea SEO fills in alt text

Rilea SEO works at two points: when you upload an image, and when a page is displayed.

On upload

When you upload an image to the media library, Rilea SEO looks at its file name and turns it into readable text. Hyphens and underscores become spaces, words are capitalised, and the leftovers WordPress adds, such as "scaled" or image dimensions, are removed. A file named blue-trail-running-shoe.jpg gets the alt text and title "Blue Trail Running Shoe".

If the image already has alt text, perhaps because it came with the file, Rilea SEO leaves the alt text alone.

On output

Older images, and images added by other plugins or themes, may still have no alt text. When a page is displayed, Rilea SEO checks the images in the content and the featured image. Any image without alt text gets it from your alt text template. This doesn't change anything stored in your database: it adds the attribute to the page as it's sent to the browser, so the fix applies everywhere at once, including thousands of old posts.

Templates

The alt text template decides what's added on output. The default is the file name, cleaned up as described above. You can use any Rilea SEO variable, such as the post title, the site name or the separator, alongside the file name. For example, a template of the file name followed by the post title gives "Blue Trail Running Shoe - How to Choose Trail Running Shoes".

A separate template controls title attributes, which are off by default. Title attributes show as a tooltip when someone hovers over the image. They have little SEO value and can be repetitive for screen reader users, so only turn them on if you have a reason to.

Images in your sitemap

When image sitemaps are on in Rilea SEO's sitemap settings, every entry in your post, page and product sitemaps also lists the images in that content, including the featured image. Images hosted on your own domain are included, so search engines can find them even if they'd otherwise miss them. The sitemap viewer at /sitemap_index.xml shows the number of images for each URL.

Images on social media

When a page is shared on Facebook, LinkedIn, X and other networks, the share image comes from Rilea SEO's Open Graph tags. Rilea SEO uses the image you set in the Social tab of the Rilea SEO panel, then the featured image, then the first image in the content, then the default share image from your settings. For images in your media library, it also prints the image's width, height, type and alt text, which helps networks display it correctly first time. The social sharing page has more detail.

Writing better alt text yourself

Automatic alt text based on file names is much better than nothing, but it's only as good as your file names, and it can't describe what makes an image important. For images that carry meaning, write the alt text yourself in the media library or the image block's settings. A few guidelines:

• Describe what's shown. Say what the image shows that matters to the page, in a sentence or a short phrase.
• Keep it short. Most alt text should be under about 125 characters. Screen readers read it all, so long descriptions are tiring.
• Use context. The same photo of a shoe might be described by colour on a product page and by activity on a blog post about trail running.
• Include keywords naturally. If the image genuinely shows the thing your page is about, use those words. Don't stuff in keywords that aren't in the picture.
• Skip "image of" and "picture of". Screen readers already announce that it's an image.
• Leave decorative images empty. Purely decorative images, such as background patterns or dividers, should have empty alt text so screen readers skip them.

Naming image files

Because Rilea SEO turns file names into alt text, good file names now do double duty. Before uploading, rename files from camera defaults like IMG_4821.jpg to descriptive names like blue-trail-running-shoe.jpg. Use hyphens between words, keep names short, and describe the content rather than the page. File names also appear in image URLs, which search engines read too.

Image SEO beyond text

Text tells search engines what an image is. Other factors decide whether it helps or hurts your page:

• File size. Large images slow pages down, which hurts visitors and can affect rankings. Compress images before upload or use an image optimisation plugin or your host's image service.
• Format. Modern formats such as WebP and AVIF are much smaller than JPEG and PNG at the same quality. WordPress supports both.
• Dimensions. Upload images at the size they'll be shown, not straight from a camera. WordPress creates smaller versions for different screens automatically.
• Lazy loading. WordPress lazy-loads images below the fold by default, so they don't slow the first view of the page.
• Placement. Put important images near the text they illustrate. Search engines use surrounding text to understand images.

Rilea SEO handles the SEO metadata. For file size and format, pair it with an image optimisation tool.

Image SEO for online stores

Product images are where image SEO pays off most. Shoppers often search Google Images for products, and product photos appear in shopping results. For WooCommerce stores:

• Give product images descriptive file names that include the product name and a distinguishing detail, such as colour.
• Write alt text for the main product image yourself, and let Rilea SEO fill in gallery images if you don't have time for all of them.
• Make sure the main product image is the featured image, because that's the one used in Rilea SEO's Product schema and social tags.

On Shopify, Rilea SEO's grid editor lets you edit alt text for product, collection and article images in bulk, and the content analysis checks that every product image has alt text.

Settings at a glance

• Alt text and title from the file name on upload. On by default.
• Missing alt attributes added on output. On by default.
• Alt text template. The file name by default; any variables can be added.
• Missing title attributes added on output. Off by default.
• Title template. The post title, separator and file name by default.

If you're moving from Rank Math, which also adds missing alt text on output, you'll see the same kind of result with Rilea SEO's defaults. Check your template to match the format you had before.

Checking your images

To see how your site is doing, run a few important pages through Rilea SEO's SEO Analyzer. It counts the images on the page and how many are missing alt text, as the browser receives them, so you'll see the effect of the output fix straight away. In the post editor, the content analysis also checks whether your focus keyphrase appears in image alt text, which is a useful prompt to write descriptive alt text for the main image on each post.

For a full audit, look through the media library in list view, where WordPress shows each image's alt text. Start with images on your most visited pages and your best-selling products, and write proper descriptions for those first. The automatic alt text covers everything else while you work through them.

If a post has no images at all, the analysis suggests adding relevant images with descriptive alt text. Most posts are easier to read with at least one image that illustrates the main point, and it gives the page a chance to appear in image results as well as regular search.

Image SEO is a small habit with a long payoff. Once descriptive file names and alt text become routine, every new post adds images that search engines and screen readers can understand, with no extra work later.