Describe and lighten images so that they support the text
Description
This criterion checks the images of the page. Among content images (visible, at least 50 × 50 px, not marked as decorative), at least 90% must have alternative text and 90% must declare their dimensions. At least 80% of raster images must be in WebP or AVIF (SVG files are not counted), and no image may exceed 500 KB.
iPand checks that alternative text is present, not that it is accurate, and does not judge the visual quality of images.
Why it matters for AI engines
A robot that reads the page text only sees an image through its alternative text. Google uses it, together with computer vision and the page content, to understand what an image is about, and recommends supporting your text with high-quality images. Images are also often the largest part of a page’s weight.
- Precise alternative text says what the image shows: a product, a place, a person.
- WebP and AVIF compress much better than JPEG and PNG: the page loads faster.
- Declared dimensions reserve the image’s space and stop the page from shifting while it loads.
How to fix it
- 1 Describe each image in its alternative text Fill in the alt attribute of each useful image with a short sentence: “Blue electric cargo bike in front of the workshop” rather than “image1” or a list of keywords. For a purely decorative image, leave the alt empty (alt=""): it is not counted.
- 2 Convert images to WebP or AVIF Export photos and illustrations as WebP or AVIF, from your editing tool or a plugin of your CMS. To keep a JPEG fallback, offer both in a <picture> element: the browser only downloads the first format it can read.
- 3 Lighten heavy images No image should exceed 500 KB. Resize each image to its display size, compress it, and offer several sizes with srcset and sizes so that mobile devices receive a suitable version.
- 4 Declare width and height Add the width and height attributes to each <img> tag, matching the image’s proportions, or reserve its space with the CSS aspect-ratio property. The browser then keeps the space while loading, even if the stylesheet later adjusts the size.
Key takeaway
Described, light images with declared dimensions help search engines understand the page and make it faster. iPand checks these four points at every analysis; the accuracy of your alternative texts is still yours to review.
