How to write alt text for marketing images on Mac: informative and decorative examples

Alt text is a short written description of an image. Screen readers speak it in place of the picture. On a Mac, that listener is usually VoiceOver. This page covers one job: deciding what each marketing image needs, writing it well, and checking it before you publish.

Start with one question: does the image carry meaning?

Every image on your page falls into one of two groups. Informative images add something the text does not say. Decorative images fill space, set a mood, or repeat what the page already says. Sort each image before you write any alt text.

1. Would the page lose information if this image disappeared?
2. Does the image show a product, a result, a place, or a person the reader needs to know about?
3. Does a sentence right beside it already say what the picture shows?
4. If the first two answers are no, or the third answer is yes, treat the image as decorative.

Be honest when you answer. Marketers often call every picture informative because they chose it on purpose. A picture can be chosen for looks and still be decoration. A hero photo of a person with a laptop is decorative when the headline already says the same thing. It is informative when the photo shows your real product in use.

Write informative alt text as one plain sentence

Informative alt text works best at about one sentence. NN/g suggests roughly 150 characters. Start with the subject, then add the detail that matters for this page. Skip the words image, photo, and picture. Screen readers already tell the listener that a picture is there.

Try a worked example. You have a product photo of a canvas tote. The bag is navy, has brown leather handles, and sits on a wooden bench. The bag is what the page sells, so the alt text names it first.

• Bad: IMG_4471.jpg. The listener hears a file name and gets nothing from it.
• Weak: tote bag. It names the product but leaves out what the reader sees.
• Better: Navy canvas tote with brown leather handles on a wooden bench.

Drop the bench if the page only sells the bag. Keep it if the setting matters, such as a shot that shows the bag at a market. The rule is simple. Describe what the reader needs to know, then stop.

Mark decorative images so screen readers skip them

A decorative image still needs an alt attribute, but the value is empty. W3C's decision tree says a purely decorative image gets an empty alt. NN/g adds that you should always include the attribute, even when it is empty. Without it, some screen readers may announce the file name instead.

Your design tool may use different words for the same step. In Word, PowerPoint, and Excel, the Alt Text pane has a Mark as decorative tick box. Ticking it greys out the description field. Figma keeps alt text in the Accessibility section of the sidebar and has a decorative option too.

Typical decorative images in marketing include swoosh dividers, faint background textures, icon rows beside labels, and stock photos that repeat nearby text. A stock photo of a laptop beside a paragraph about laptops is decorative. Describing it twice only slows the listener down.

Describe charts briefly and put the data in text

A chart is the hardest common case. Alt text cannot hold every bar and label. W3C's guidance says to describe a complex graph briefly and include the full information elsewhere on the page. Name the chart and its main point. Skip the list of values.

Take a bar chart of monthly signups that rises from January to June. Alt text: Bar chart of monthly signups, rising each month from January to June. Under the chart, add a small table with each month and its count. Build that table in Google Sheets, then paste it into your doc or CMS.

Text inside a banner belongs in the alt text

Many campaign banners put the headline inside the picture. Screen readers cannot read text baked into an image as well as real text. Apple says screen readers do not work as well when text is embedded in an image. Copy the words into alt text exactly as shown.

Write what the banner says, not how it looks. Summer sale: half price on canvas totes is useful. Blue banner with white text and an arrow describes the paint, not the message. Keep the headline as live text on the page wherever your layout allows it.

Linked images need alt text that says where the link goes

Linked images need the most care. WebAIM's 2026 scan found that 45% of images missing alt text were linked images. One in four linked images had no alt text at all. Treat a linked image like a button, because a listener hears the alt text as the button's label.

A logo that links to your home page needs alt text like Brand name home page. A product card that opens the product page needs the product and the action, such as Shop navy canvas tote. Keep it short. The listener hears it before they decide to click.

Set alt text in the tools you use on a Mac

Alt text lives in the file or the page, so set it in the tool that publishes the image. Each tool puts the field in a different place. These are the paths this page could confirm.

• Keynote, Pages, or Numbers: select the image, click Format in the toolbar, then type in the Description box.
• Word, PowerPoint, or Excel: open the Alt Text pane for the picture, then type a description or tick Mark as decorative.
• Figma: select the element, open the Accessibility section in the sidebar, then write the alt text.
• Canva for marketers and your CMS: check the help page for that tool. Current Mac steps were not confirmed for this page.

Google Docs and other doc tools need a separate check. Confirm where alt text lives in your tool before you assume it exists. Do not put alt text in a comment, because a comment is not part of the published image.

Check alt text with VoiceOver and a Chrome audit

Test what a listener hears. Turn on VoiceOver with ⌘F5. Open the page in Chrome, then move through the images with the VO keys, which are Control and Option together. An image with no description makes VoiceOver speak its file name. That is your failure signal.

Apple says you can turn on image descriptions in VoiceOver Utility. After that, VO-Shift-L describes web images on the device. Use it to hear what a listener gets from an image with no alt text. Do not treat its output as your final copy.

For a quick scan, open Chrome and press ⌥⌘I to open Developer Tools. Choose the Lighthouse tab and run an accessibility audit. Lighthouse includes an alt text check and flags missing alt. It cannot tell you whether the words are good. Treat it as a first filter.

Use AI to draft alt text, then check every word

AI can draft alt text quickly. A 2026 arXiv study had 12 disability services professionals write alt text for HCI figures with generative AI support. Expert raters found the AI-assisted text higher in quality. The writers also reported problems interacting with the AI. The study did not test with blind screen reader users.

Apple's Image Explorer also uses Apple Intelligence to describe images on screen in more detail. Apple's accessibility page does not name a macOS version, so check your own system before you plan around it.

Check every draft for four things. Does it name the right product and color? Does it invent a brand or a number? Does it miss visible text? Does it describe a mood instead of the subject? Fix each problem before you publish.

A worked example: one landing page with four image types

Here is a sample landing page. It has a hero photo, a chart, a banner with a headline, and a logo that links home. Each image needs a different decision. The table shows one way to sort them. It is an example, not a real campaign.

Notice what the table leaves out. It does not mention the photographer, the lighting, or the campaign name. Listeners need what is on the page and why it matters. The backstory can stay in your brief.

Mistakes that repeat across marketing teams

• Leaving the file name in place. The listener hears the code, not the picture.
• Writing alt text as a keyword list. Stuffed words are harder to follow when spoken.
• Marking product photos as decorative. A product shot usually carries the information.
• Skipping the logo link. A linked logo with no alt text is a button with no label.
• Writing a long paragraph. Keep the alt to one sentence and put detail in the page text.
• Writing for an image that is not placed yet. Check the final crop and where it sits.

Make alt text part of publishing, not a cleanup job

Alt text is easiest when the image goes into the page. Make it one step in the same pass. Write the alt text, mark decorative images, then preview the page. Add a line to your publishing checklist so the step is not optional.

Keep a shared sheet with one row per image. Use columns for page, file, type, alt text, owner, and checked. Then filter for blank alt text to find gaps. The steps for filtering are in how to add a filter in Google Sheets.

Who writes, who checks

Split the job across two people. The person who knows the message writes the alt text. A designer marks decorative images in the design tool. A second person checks the page with VoiceOver. On a short page that check is a quick job. Two people catch what one person misses.

Start with the next page you publish. Run the three questions on each image, then test one image with VoiceOver. The pattern becomes routine after a few pages.