Home
>
Web Development
>
Writing Effective ALT Text For Images

Writing Effective ALT Text For Images

Anyone who knows anything about web accessibility knows that images need alternative, or ALT, text assigned to them. This is because screen readers can't understand images, but rather read aloud the alternative text assigned to them. In Internet Explorer we can see this ALT text, simply by mousing over the image and looking at the yellow tooltip that appears. Other browsers (correctly) don't do this. The HTML for inserting ALT text is:

img src="filename.gif" alt="Alternative description goes here"

But surely there can't be a skill to writing ALT text for images? You just pop a description in there and you're good to go, right? Well, kind of. Sure, it's not rocket science, but there are a few guidelines you need to follow...

Spacer images and missing ALT text

Spacer images should always be assigned null ALT text, or alt="" . This way most screen readers will completely ignore the image and won't even announce its presence. Spacer images are invisible images that pretty most websites use. The purpose of them is, as the name suggests, to create space on the page. Sometimes it's not possible to create the visual display you need, so you can stick an image in (specifying its height and width) and voli?, you have the extra space you need.

Not everyone uses this null ALT text for spacer images. Some websites stick in alt="spacer image". Imagine how annoying this can be for a screen reader user, especially when you have ten of them in a row. A screen reader would say, "Image, spacer image" ten times in a row (screen readers usually say the word, "Image", before reading out its ALT text) - now that isn't helpful!

Other web developers simply leave out the ALT attribute for spacer images (and perhaps other images). In this case, most screen readers will read out the filename, which could be 'newsite/images/onepixelspacer.gif'. A screen reader would announce this image as "Image, newsite slash images slash one pixel spacer dot gif". Imagine what this would sound like if there were ten of these in a row!

Bullets and icons

Bullets and icons should be treated in much the same way as spacer images, so should be assigned null alternative text, or alt="". Think about a list of items with a fancy bullet proceeding each item. If the ALT text, 'Bullet' is assigned to each image then, "Image, bullet" will be read aloud by screen readers before each list item, making it take that bit longer to work through the list.

Icons, usually used to complement links, should also be assigned alt="". Many websites, which place the icon next to the link text, use the link text as the ALT text of the icon. Screen readers would first announce this ALT text, and then the link text, so would then say the link twice, which obviously isn't necessary.

(Ideally, bullets and icons should be called up as background images through the CSS document - this would remove them from the HTML document completely and therefore remove the need for any ALT description.)

Decorative images

Decorative images too should be assigned null alternative text, or alt="". If an image is pure eye candy then there's no need for a screen reader user to even know it's there and being informed of its presence simply adds to the noise pollution.

Conversely, you could argue that the images on your site create a brand identity and by hiding them from screen reader users you're denying this group of users the same experience. Accessibility experts tend to favour the former argument, but there certainly is a valid case for the latter too.

Navigation & text embedded within images

Navigation menus that require fancy text have no choice but to embed the text within an image. In this situation, the ALT text shouldn't be used to expand on the image. Under no circumstances should the ALT text say, 'Read all about our fantastic services, designed to help you in everything you do'. If the menu item says, 'Services' then the ALT text should also say 'Services'. ALT text should always describe the content of the image and should repeat the text word-for-word. If you want to expand on the navigation, such as in this example, you can use the title attribute.

The same applies for any other text embedded within an image. The ALT text should simply repeat, word-for-word, the text contained within that image.

(Unless the font being used is especially unique it's often unnecessary to embed text within images - advanced navigation and background effects can now be achieved with CSS.)

Company logo

Websites tend to vary in how they apply ALT text to logos. Some say, 'Company name', others 'Company name logo', and other describe the function of the image (usually a link back to the homepage), 'Back to home'. Remember, ALT text should always describe the content of the image so the first example, alt="Company name", is probably the best. If the logo is a link back to the homepage then this can be effectively communicated through the title tag.

Conclusion

Writing effective ALT text isn't too difficult. If it's a decorative image then null alternative text, or alt="" should usually be used - never, ever omit the ALT attribute. If the image contains text then the ALT text should simply repeat this text, word-for-word. Remember, ALT text should describe the content of the image and nothing more.

Do also be sure also to keep ALT text as short and succinct as possible. Listening to a web page with a screen reader takes a lot longer than traditional methods, so don't make the surfing experience painful for screen reader users with bloated and unnecessary ALT text.

This article was written by Trenton Moss. He's crazy about web usability and accessibility - so crazy that he went and started his own web usability and accessibility consultancy ( Webcredible - http://www.webcredible.co.uk ) to help make the Internet a better place for everyone.

one time home cleaning Highland Park ..

In The News:

Privacy risks are hiding in plain sight, as your personal data is likely being collected, tracked, and sold without your knowledge.

VenHub, a fully autonomous, AI-powered smart store just opened at the LAX/Metro Transit Center in Los Angeles.

A woman's Facebook account takeover reveals dangerous social engineering tactics and provides lessons on recovery, avoiding scams and enacting stronger security measures.

Shanghai engineers are using 432 walking robots to relocate a complex, preserving Shikumen architecture while creating space for a modern underground hub and cultural center.

Major healthcare data analytics firm Episource had a cybersecurity incident exposing 5 million patients' medical records and personal information in recent breach.

A new sophisticated PayPal scam sends legitimate-looking emails from official PayPal addresses, using phone numbers instead of links to convince victims to download remote access tools.

Fox News' AI Newsletter brings you the latest on this rapidly evolving technology.

The innovative Kara Pod device extracts moisture from air to create mineral-rich water and brew coffee, featuring UV sterilization and compatibility with Nespresso pods.

Gov. Hochul unveiled New York's nuclear power plant project to power a million homes, which faces permit challenges while promising jobs and a cleaner energy future.

SAFE introduces Aerie, an underground luxury bunker combining high-end living with advanced security, wellness amenities and interactive walls simulating panoramic views.

A Facebook scammer posing as Elon Musk tricked a victim with promises of a Tesla and $250,000, requesting gift cards that become untraceable once the codes are shared.

Experience hands-free golfing with the Robera Neo smart caddie that uses AI to follow you, navigate obstacles and carry your clubs with GPS course mapping.

Cybersecurity alert: 16 billion passwords exposed in massive credential database affecting major platforms. Protect your accounts with password managers

The innovative BeBot robot uses electric power to remove pollution from shorelines, covering 20-30 times more area than manual collection while preserving wildlife.

A new ClickFix campaign targets macOS users with fake Spectrum support sites, tricking victims with CAPTCHA failures to paste commands that install information-stealing malware.

AI-powered autonomous trucks from Plus Automation are being tested across the U.S., Europe and Asia to solve logistics challenges while facing regulatory hurdles and labor concerns.

Your health information might feel private and secure with your doctor, but the reality is far more complicated. Data brokers collect a wide range of sensitive health data, from diagnoses and prescription details to personal identifiers, and sell this data to marketers, insurers, and other third parties.

Kepler Robotics has officially introduced its Forerunner K2 "Bumblebee" humanoid robot at the SAIC-GM automotive plant in Shanghai, marking a significant moment in the real-world deployment of advanced robotics.

Scammers never seem to be running out of new ways to try and get their hands on your money – and lately, they've been getting sophisticated.

Thirty people were injured and killed, though the exact number remains currently unknown, when a suicide bomber blew himself up in a Damascus church.

Unexpected password reset alerts signal potential hacking attempts or phishing scams. Learn how to respond and establish stronger security measures for your accounts.

A historic electric airplane flight landed at JFK with passengers, marking a milestone as Beta Technologies demonstrates the practicality and efficiency of electric air travel.

The Chaos ransomware group breached Optima Tax Relief in a double-extortion attack, stealing sensitive customer case files and corporate documents with personal information.

Stay up to date on the latest AI technology advancements and learn about the challenges and opportunities AI presents now and for the future.

The first human brain-computer interface by Paradromics was completed in 20 minutes, featuring microelectrodes to help paralyzed individuals control computers with thoughts.

Writing Effective ALT Text For Images

Web Development