What Is Image Optimisation? | Marketing Dictionary
DICTIONARY · WEB

What is image optimisation?

Reducing image size while maintaining appropriate quality and usability.

In plain English

Image optimisation is making images as small as they can be without looking bad. Correct dimensions, a sensible format, sensible quality, and only loading what is needed.

This is the biggest single performance problem on most business websites. A page carrying six photographs straight off a phone camera is downloading many times more data than it needs to.

What to know

Resize before uploading
An image displayed at eight hundred pixels wide does not need to be four thousand. Resizing first is the largest saving available.
Choose the right format
Photographs suit JPEG or WebP, graphics and screenshots suit PNG or SVG. Modern formats are meaningfully smaller.
Compress with judgement
Most photographs tolerate substantial compression invisibly. Compare before and after rather than guessing.
Alt text and file names
Descriptive names and alt text serve accessibility and image search. Optimisation is not only about weight.

Why it matters

Images usually account for most of a page weight, so this is where speed work pays best. It is also the one part of performance a marketing team can do entirely themselves, with no developer involved, on every page they publish from now on.

Common mistakes

×Uploading full-resolution camera or stock files directly.
×Relying on CSS to scale a huge image down, so the browser still downloads all of it.
×Using PNG for photographs, which multiplies file size.
×Leaving alt text empty on images that carry meaning.

FAQs

What size should images be?

No larger than the space they display in, at most twice that for high-density screens. For most content images, under two hundred kilobytes is a reasonable target.

Should I use WebP?

Yes where supported, and it is now widely supported. Most optimisation plugins will convert and serve it automatically.

WRITTEN BY TARIQ SALLAM
Marketing Consultant. Entrepreneur. Content Creator.

I'm a marketing consultant, entrepreneur and content creator. I help businesses grow through practical marketing, websites, SEO, content and AI.

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