Crafted
Help visually impaired users understand your content with meaningful alt texts
17 November 2025
Appropriate alt texts are a must-have to meet the Digital Service Standards. Here are some tips on writing effective alt texts and making images accessible.
Crafted is a series of tips to make your sites more accessible, usable, and clear. The Isomer team studies these topics and writes each guideline, word by word.
Alt texts are not optional
Alternate (”alt”) texts are short descriptions that you add to images. They’re hidden because you can’t read them like any other text. But screen readers read them aloud, and browsers display them if an image doesn’t load. Alt texts help visually impaired readers understand your pages fully.
They can also help users with weak connectivity. Imagine a Singaporean overseas trying to understand a grant, but an infographic doesn’t load. Alt texts ensure nothing important is lost.
You need alt texts for compliance
If you manage a government website, you must include appropriate alt texts to meet the Digital Service Standards (DSS) guidelines which follow the Web Content Accessibility Guidelines (WCAG).
How to write descriptive alt texts
All images need alt texts unless they are decorative.
💡 As of now, Isomer Studio doesn’t support marking an image as “decorative”. If you’re confident that an image doesn’t add meaning that isn’t already described elsewhere, you can enter a hyphen “-”.
Don’t start your alt text with “Image of…” or “Photo of…”
Screen readers already announce that there’s an image. Jump straight to the content.
Describe the image in context
If it’s a photo of people, describe the scene in the context of your page:
“Doctor consulting an elderly patient.”
“Volunteers handing out goodie bags at a community club.”
If it’s a process, chart, or data visualisation, summarise the key takeaway:
“Three ways of applying for a pass: in-person, online, and through mail.”
“Stress levels have been dropping by 15% since the programme started.”
Don’t assume or infer things the image doesn’t show
Avoid adding emotions, opinions, or subjective details.
What NOT to write:
“An elderly woman beaming with joy”
“One of the most beautiful cats sitting in a void deck”
More tips to make images accessible
Don’t add infographics or charts without a description
Many agencies use infographics or charts that explain a policy visually. Unfortunately, not only are they impossible for screen readers, but they are rarely easy to see — especially on mobile, where they become tiny or pixelated.
Always provide a text version of the key information below the infographic.
Avoid text on images altogether
Text on images cannot be read by screen readers.
They can also cause other problems:
They can be hard for even sighted users to read if fonts and colours are poorly chosen.
They are hard to maintain. You need the original file (sometimes in a format like .ai) even if you want to make a simple fix.
They are not searchable by Google or SearchSG, which means the content becomes invisible to search engines.
Resources
Alt text decision tree by W3C
Google's guidelines on alt texts