How to Write Helpful Alt Text for Website Images

Learn how to write helpful alt text that makes website images accessible for screen reader users and improves search engine clarity.

Alternative text, commonly known as alt text, acts as a functional substitute for visual elements on a webpage. When visitors use screen readers due to vision impairments, assistive technology reads these text descriptions aloud (Google Developers). Writing clear alt text requires a balanced approach that focuses on the image’s specific purpose within the surrounding content rather than listing every visual detail.

How to Write Helpful Alt Text for Website Images: 1. Understand the Image Role in Context

Before drafting any description, evaluate what the image communicates. An image rarely exists in a vacuum. Its meaning often depends heavily on the surrounding paragraphs. For instance, a photograph of a bird requires a simple species label in an article about general wildlife, but needs a detailed description of its physical posture and plumage in an article focusing on winter survival adaptations. Read through the adjacent text first to determine what essential message would be lost if the image disappeared entirely.

2. Keep Descriptions Concise and Direct

Good alt text should be brief and to the point. Most screen reader users prefer concise explanations that do not interrupt the flow of reading (Google Developers). Avoid starting your descriptions with phrases like image of or photo of because assistive technology already announces that the element is an image. Focus directly on the core subject, action, or context.

• Describe the primary subject and relevant action clearly.
• Include readable text shown inside the graphic only when it matters.
• Keep language natural and straightforward.
• Avoid stuffing excessive search terms into the description.

Practical Steps for Evaluating Image Purpose

To ensure every graphic on your website serves a legitimate communicative purpose, you should follow a systematic evaluation workflow before publishing content. First, examine whether removing the image entirely would alter the understanding of the page. If the answer is yes, determine the exact takeaway the graphic provides. Second, verify whether the information is already fully explained in the surrounding text. If redundant text exists, treat the graphic as supplementary and keep the description brief. Third, draft a literal translation of the visual elements without adding subjective commentary or marketing flair. Finally, read the drafted description aloud to verify that it flows naturally and maintains clarity without burdening assistive technology users with overwhelming verbal clutter.

3. Handle Decorative Images Correctly

Not every graphic on a website requires alternative text. When an image serves a purely aesthetic purpose—such as a background divider, a decorative shape, or an icon that merely repeats nearby text—it should have an empty alt attribute (Google Developers). Leaving the attribute empty tells screen readers to skip the element entirely, preventing unnecessary audio clutter for your visitors.

4. Describe Charts and Complex Visuals

Complex graphics like data charts, diagrams, or floor plans cannot always be summarized adequately in a single brief sentence. When dealing with intricate visuals, provide a short alt text summary that gives the primary takeaway, and place the exhaustive explanation within the main body text or in a dedicated data table (Google Developers). This ensures all users can access the full scope of the data.

Common Pitfalls and Decision Criteria

When implementing alternative text across extensive digital content libraries, creators often encounter recurring challenges that require careful governance. One common error involves keyword stuffing, where publishers insert unrelated search queries into the alt attribute, which degrades the experience for assistive technology users and fails to improve semantic relevance. Another risk is providing overly verbose descriptions for standard thumbnails or author headshots. Use clear decision criteria: if an image acts purely as a link, the alternative text must describe the destination or function of the link rather than just the visual appearance of the icon. Routine content audits help identify missing attributes and ensure consistent adherence to accessibility standards.

5. Review and Refine Your Work

Quality assurance is an essential final phase in publishing accessible content. Test your pages by reviewing them without rendering the images. Check that your descriptions are free from redundant phrases and spelling errors. For broader publishing workflows, you can also explore related advice on how to create a branded email address for your website or review your setup by following tutorials guides on Pilume, alongside ensuring you maintain a complete website backup before major changes.

Related reading: How to Write Effective Meta Descriptions That Earn More Clicks in SERPs