Images on the website: quality, speed and understandable context

Choose an image for the task

In the store, the photo is intended to enable product evaluation; the guide may explain the step. The general illustration does not replace a photo of the connector, dimensions or detail important for purchase. First, decide what you want the viewer to understand from the image.

Google recommends providing images in supported HTML, meaningful context, and descriptive alt text. An image embedded solely as a CSS background is not treated the same as an image in an img element.

Source: Google: good practices for images ↗

Prepare variants instead of one huge file

Adjust widths to actual display locations. The browser can select the variant by srcset and sizes. Check the format and compression on a photo with fine details, not just on a plain background. Too much compression may make it difficult to evaluate the product.

Take care of the place and moment of charging

Provide dimensions or correct proportions so the browser can reserve space. Images far below the first screen may benefit from deferred loading. Don't automatically apply it to the most important photo visible upon entry - check the effect on LCP.

Also evaluate framing on your phone. A technically correct file may truncate an important inscription or product element. Inspection on a wide monitor does not replace evaluation of a small screen.

An alternative description is intended to convey meaning

Describe important content in the context of the page. Do not add a list of positioning phrases. A decorative image can have blank alt text; an important graph needs an accessible explanation of the data beyond the bitmap itself.

After deployment, check for broken links, variant loading, and appearance on slower connections. Optimization is complete when the image still serves its purpose, not just when the file size is smaller.