Choosing and Optimising Photographs for Your Website

Images are both the most persuasive and the most slowing element of a site. Here are the rules for choosing the right photograph and publishing it without hurting performance.

A visitor's first impression forms through imagery before they read a word. At the same time, images are the largest contributor to page weight. In other words, the most persuasive element and the slowest element are the same element. The balance is struck both in what you choose and in how you prepare it.

Choosing the right photograph

The problem with generic stock imagery is not that it looks bad but that it says nothing. A smiling group around a meeting table fits every industry and therefore belongs to none. Wherever possible use photographs of your own work, your own team and your own premises. An imperfect real photograph inspires more trust than a flawless artificial one.

If you must use stock, avoid the most popular images. Finding the same photograph on a competitor's site undermines you both.

Preparation before publishing

• Serve at real size: Uploading a very high-resolution file for a small display area burdens the browser for nothing. Prepare the image at the size it will be used.
• Use modern formats: Current formats deliver the same visual quality at a substantially smaller file size. The saving is significant and usually invisible to the eye.
• Decide the crop yourself: If an image will be cropped differently across screens, decide where the important element sits. Otherwise faces and products get cut at the edges.
• Name files meaningfully: Descriptive filenames beat random characters, and they matter in image search.

Alt text: accessibility and search

Alt text is the verbal equivalent of an image for people who cannot see it; screen readers read it aloud. It also helps search engines understand the image. Two mistakes are common: leaving it empty entirely, and turning it into a keyword list. The correct approach is a short, plain sentence describing what the image shows.

Do not take licensing lightly

Not every image found online is free to use. Unlicensed use of a copyrighted photograph can return as a serious claim years later. Keep a record of the source and licence of every image you use. That record becomes your strongest defence if a claim ever arrives.

Final check

Before launch, review your images on a mobile device and a weak connection. A gallery that loads flawlessly on office wifi can lose you the visitor on mobile data.