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Accessibility
Why does every image on the website need alt text?
Every image needs an alt text because blind people and search engines can only grasp the image's content through this text. A screen reader reads the alt text aloud, and Google shows images with good alt text in image search. If the text is missing, a blind visitor only hears the file name — say, "DSC_0042.jpg" — and understands nothing.
Alt text: the word description of an image
The alt text is a short sentence attached to the image in the page's source code. Sighted visitors never see it. A blind visitor has the page read aloud by a screen reader — and at the point where the image sits, the program reads out exactly this text. An example: your team page shows a photo of the managing director. With the alt text "Portrait of Maria Huber, Managing Director", the visitor knows who they're looking at. Without the text, only a gap remains. Google also reads this text and uses it to understand what's shown in the image — which helps your visibility in image search.
How our measurement engine checks alt texts
The automated check opens your page in a real browser and examines every single image with the axe-core testing tool. In addition, our own check step counts every image whose alt attribute is missing entirely — each one is a documented violation, which the report backs up with the file name. A deliberately empty alt text, by contrast, is correct: that's how you mark purely decorative images that a screen reader should skip. Whether an existing text is also a good fit content-wise is something no machine can decide — so the automation never prematurely confirms a "pass" here. At the Gold Standard level, a human looks at the images and their texts and makes the call.
Writing good alt texts
A good alt text describes what's shown in the image and what purpose it serves on this page — in one sentence, without the stock phrase "image of". For a product photo: "Black office chair with armrests, side view". For a linked logo, what counts is the link's destination: "To the homepage". Purely decorative images — dividers, background patterns — get an empty alt text so the screen reader silently skips them. File names, keyword lists, or promotional copy never belong in the alt text: the visitor hears every letter and loses time.
- Check your most important pages: does every image have alt text that describes its content in one sentence?
- Ask your agency to list images without an alt attribute and add it retroactively.
- Mark decorative images with an empty alt text so screen readers skip them.
- Set a rule in your editorial team: no image goes live without alt text.
- Read your alt texts aloud — if the page still makes sense without the images, the texts are good.
FAQ
What is alt text for images?
An alt text is a short description stored in the source code alongside the image. Sighted visitors don't see it. Screen readers read it aloud to blind people, and search engines use it to understand the image's content. The text should say, in one sentence, what's shown in the image.
Do decorative images also need alt text?
Yes, but an empty one: the source code then contains alt="" — an alt attribute with no content. This tells the screen reader that the image is purely decorative, and it skips it. If the attribute is missing entirely, on the other hand, the program often reads out the file name instead, which confuses the visitor.
Does alt text also help with Google?
Yes. Google can only interpret images to a limited extent on its own and relies on the alt text to understand what an image shows. Images with accurate alt text are more likely to appear in Google image search. So the same text helps both blind visitors and your findability at once.
How does the audit service check alt texts automatically?
The automated check opens the page in a real browser and, using the axe-core tool plus a check step of our own, counts every image without an alt attribute — each one is a documented violation. Whether existing texts are a good content fit is judged by a human at the Gold Standard level, since that requires actually understanding the image.