What is Image Alt Text?

Image alt text (sometimes called an alt tag or alternative text) is a short written description added to an image to explain what the image shows.

Its main purpose is to help people who cannot see the image, including users who rely on screen readers or other assistive technology. It can also help provide context if an image does not load properly, and it gives search engines a better understanding of the image content.

For organisers using ShowOff, you do not need to add any code to include alt text. ShowOff includes alt tag fields throughout the platform when adding imagery, so you can add this information wherever images are used in the CMS.

What Does Alt Text Do?

Alt text has three main functions:

Accessibility

Alt text helps visually impaired users understand the purpose or content of an image. Screen readers will read the alt text aloud, so the user still gets the context the image provides.

Context

If an image fails to load, the alt text may be shown in its place or used to explain what should have appeared.

SEO

Alt text helps search engines understand what an image relates to. While alt text should never be written just for SEO, adding clear and accurate descriptions can support your page’s overall relevance.

Why Alt Text Is Important

Alt text is important because images often carry useful meaning.

For example, an image might show:

• a speaker on stage

• an event floorplan

• a sponsor logo

• a product image

• an infographic

• a call-to-action banner

If that image has no alt text, some users may miss important information completely.

Good alt text helps make your website more:

• accessible

• user-friendly

• search-engine friendly

• professionally maintained

What Makes Good Alt Text?

Good alt text should be:

Accurate

It should describe what is actually shown in the image.

Concise

It should be clear and useful without becoming overly long.

Relevant

It should focus on the part of the image that matters in the context of the page.

Natural

It should read like a normal description, not a list of keywords.

Alt Text Should Match the Purpose of the Image

A good alt text description depends on why the image is being used.

For example, if the image is being used to show a venue entrance, the alt text should describe that.

If the image is being used to highlight a keynote speaker, the alt text should focus on the speaker.

This means the same image could have different alt text depending on where and how it is used.

Examples of Good Alt Text

Here are some examples of strong alt text:

Example 1: Event photo

Image: A speaker presenting on stage to a large audience
Good alt text:
Keynote speaker presenting on stage to attendees at a live conference

Why this works:

• clear

• descriptive

• explains the important content of the image

Example 2: Venue image

Image: Main entrance to an exhibition venue
Good alt text:
Main entrance to the exhibition venue with event branding displayed outside

Why this works:

• tells the user what the image shows

• gives useful context

Example 3: Registration area

Image: Attendees checking in at registration desks
Good alt text:
Attendees registering at the event welcome desk

Why this works:

• short

• specific

• relevant to the page topic

Example 4: Floorplan image

Image: A map of the event floor
Good alt text:
Floorplan showing exhibitor stands, theatre areas and registration points

Why this works:

• explains the content clearly

• useful for accessibility and context

Example 5: Sponsor logo

Image: A sponsor logo used on a sponsorship page
Good alt text:
ABC Events sponsor logo

Why this works:

• simple

• appropriate for a logo

• clearly identifies the image

Examples of Poor Alt Text

Too vague

image
photo
banner

These do not tell the user anything useful.

Too keyword-focused

event conference exhibition business expo event venue conference visitors

This is not natural and is not helpful for accessibility.

Too generic

people at event

This may be technically true, but it is not very useful if the image shows something more specific.

Too long

A very long description can be difficult to read and is often unnecessary unless the image contains important detailed information.

Should Alt Text Always Describe Every Detail?

No. Alt text should describe the important content, not every visual detail.

For example, you usually do not need to include:

• clothing colours unless relevant

• exact numbers unless important

• unnecessary background detail

• phrases like “image of” or “picture of”

Most screen readers already announce that the content is an image, so writing “image of” is usually unnecessary.

For example:

Less effective:
Image of people networking at an event

Better:
Attendees networking in the exhibition hall

Decorative Images

Some images are purely decorative and do not add meaningful information to the page.

For example:

• background textures

• design flourishes

• decorative shapes

• purely visual dividers

In these cases, the image may not need descriptive alt text at all. The aim is to avoid adding unnecessary noise for screen reader users.

However, where an image is informative, functional, or important to the content, alt text should always be considered.

Alt Text for Functional Images

If an image acts as a link or button, the alt text should describe the action or destination, not just the appearance.

For example:

If a banner links to registration, a good alt text might be:

Register now for the event

This is more useful than:

Blue banner with event logo

The user needs to know what the image does, not just what it looks like.

Alt Text in ShowOff

In ShowOff, organisers do not need to write HTML or add image code manually. The CMS handles the technical side for you.

Importantly, ShowOff includes various alt tag fields throughout the platform when adding imagery, so you can add alt text wherever images are used across the site.

This makes it easier to ensure your pages remain:

• accessible

• informative

• better structured for search engines

When uploading or inserting images in ShowOff, it is good practice to complete the alt text field with a clear description of the image and its purpose.

Best Practice for Writing Alt Text in ShowOff

When adding images in ShowOff, try to:

• describe the image clearly

• keep the wording concise

• focus on what matters most

• write for people first, not search engines

• make sure the alt text matches the page context

For example, if you upload a venue image to a travel information page, the alt text should support that topic.

Good example:
Entrance to the venue from the main road

Less useful example:
Building

Common Alt Text Mistakes to Avoid

Leaving it blank for important images

This can make the content less accessible.

Using file names

For example:
IMG_2048.jpg

This is not useful to users or search engines.

Stuffing keywords

Alt text should describe the image naturally, not try to force SEO terms in.

Writing overly long descriptions

Keep it useful and focused.

Describing only what the image looks like, not why it matters

The context of the page matters just as much as the image itself.

A Simple Rule to Follow

A useful question to ask is:

“If someone could not see this image, what would they need to know?”

The answer to that question is usually the basis of good alt text.

Key Takeaways

• Image alt text is a short description added to an image.

• It is mainly used for accessibility, but also helps with context and SEO.

• Good alt text should be clear, concise, accurate, and relevant.

• It should describe the purpose of the image, not just fill space with keywords.

• In ShowOff, organisers do not need to add code to manage alt text.

• ShowOff includes alt tag fields throughout the platform when adding imagery, making it easy to add this information wherever needed.

Adding good alt text is a small step that can make a big difference to the quality, accessibility, and usability of your website.