What is "Alt Text"?
Alt text, short for alternative text, is a brief, descriptive HTML attribute added to images on websites and digital documents that describes their content and function. It serves as a text-based substitute when the image cannot be seen, enabling accessibility for visually impaired users and providing semantic context to search engines.
Businesses often treat alt text as a low-priority afterthought, resulting in inaccessible digital assets, poor SEO performance, and potential non-compliance with accessibility laws.
- Descriptive Text: A concise written summary of an image’s key visual information and purpose.
- Screen Reader: Assistive technology that reads alt text aloud, allowing blind and low-vision users to understand the image.
- SEO (Search Engine Optimization): Search engines use alt text to comprehend image content, which can influence a page's ranking and help images appear in search results.
- Accessibility Compliance: Laws like the EU's Web Accessibility Directive and others mandate providing text alternatives for non-text content, making alt text a legal requirement in many contexts.
- Image Context: Alt text explains the role an image plays on the page, such as illustrating a concept, linking to another page, or serving as a decorative element.
- Fallback Display: If an image fails to load, the alt text is displayed in its place, ensuring information is not lost due to technical issues.
Product, marketing, and web development teams benefit most from proper alt text implementation. It solves the core problems of creating exclusionary digital experiences and missing opportunities to communicate effectively with all users and search engine crawlers.
In short: Alt text is a critical accessibility and SEO component that describes images for users and technologies that cannot see them.
Why it matters for businesses
Ignoring alt text creates tangible business risks, including legal exposure, diminished brand reputation, and lost revenue from poor search visibility and inaccessible customer journeys.
- Legal and Financial Risk: → Non-compliance with accessibility regulations like the EAA in the EU can lead to significant fines, legal action, and costly remediation projects.
- Excluding Potential Customers: → By not describing images, you create barriers for millions of users with visual impairments, effectively turning them away and shrinking your market.
- Wasted SEO Potential: → Images without alt text are "invisible" to search engines, missing a straightforward opportunity to improve organic traffic through image search and page context.
- Poor User Experience: → When images break or load slowly, blank spaces with no description confuse all users and can lead to site abandonment.
- Ineffective Content: → Complex infographics, charts, or product images lose their informational value for anyone who cannot interpret the visuals, diluting your content's impact.
- Damaged Brand Equity: → Being perceived as a company that does not prioritize inclusivity can harm your public image and relationships with partners and clients who value corporate social responsibility.
- Inefficient Procurement: → Selecting a web agency or software vendor without verifying their accessibility and SEO expertise can lock you into platforms that make implementing proper alt text difficult or expensive.
- Poor Content Governance: → Without a clear alt text strategy, marketing and content teams create inconsistent, low-quality descriptions that fail to serve any strategic purpose.
In short: Proper alt text management mitigates legal risk, expands audience reach, enhances SEO, and protects brand reputation.
Step-by-step guide
Tackling alt text for an entire website can feel overwhelming, but a systematic approach makes it a manageable and routine part of your content workflow.
Step 1: Audit your current state
The obstacle is not knowing where to start or how severe the problem is. Conduct a technical audit to identify all images missing alt text or containing poor-quality descriptions. Use automated accessibility scanning tools to generate a report of violations. Prioritize pages with high traffic, conversion importance, or legal sensitivity.
Step 2: Establish clear guidelines and responsibility
Without guidelines, descriptions become inconsistent and subjective. Create a simple internal style guide for your team. Define who is responsible for writing alt text (e.g., content creators, SEO specialists) and who is responsible for its technical implementation (e.g., developers, CMS managers).
Step 3: Categorize your images
Not all images require the same type of description. Classify each image to determine the appropriate alt text strategy:
- Informative images: Describe the content and function (e.g., a product photo, a chart).
- Decorative images: Use an empty alt attribute (alt="") so screen readers skip them (e.g., stylistic borders, purely visual dividers).
- Functional images: Describe the action, not the picture (e.g., for an icon that is a link, "Search" not "Magnifying glass").
- Complex images: Provide a short summary in the alt text and a longer description on the page or via a link (e.g., detailed infographics, flowcharts).
Step 4: Write effective, descriptive alt text
The core challenge is moving from vague to useful descriptions. Write concisely, aiming for 125 characters or less. Be specific and objective, conveying the essential information the image provides in the context of the page. Avoid starting with "image of" or "picture of." For a quick test, read the alt text aloud and ask if it gives you the same key information as seeing the image.
Step 5: Implement within your CMS and code
The obstacle is manual, error-prone entry. Ensure your content management system (CMS) has a mandatory alt text field for image uploads. For developers, validate that all `` tags in the codebase include an `alt` attribute, even if it's empty for decorative images.
Step 6: Train your content and product teams
Knowledge gaps lead to persistent errors. Conduct practical training sessions using your style guide. Focus on the "why" (accessibility, SEO) and the "how" (your categorization system and writing principles). Use examples from your own website.
Step 7: Integrate into your publishing workflow
Alt text becomes a bottleneck if treated as a final step. Make writing alt text a required checkpoint in your content creation and approval process, just like proofreading or SEO title checks.
Step 8: Schedule periodic reviews and maintenance
Websites evolve, and alt text can become outdated or inaccurate. Include alt text quality in your quarterly content audits. Especially review alt text after major page redesigns or content updates.
In short: A successful alt text strategy involves auditing, creating guidelines, writing context-aware descriptions, implementing systematically, and maintaining through training and reviews.
Common mistakes and red flags
These pitfalls are common because alt text is often written hastily, without understanding its purpose for different audiences.
- Leaving the alt attribute empty or missing: → This creates a major accessibility barrier. Screen readers may read the image file name instead, confusing users. Fix: Always include the `alt` attribute. Use `alt=""` only for decorative images.
- Keyword stuffing for SEO: → Stuffing alt text with irrelevant keywords (e.g., "cheap shoes discount running sneakers sale") is a poor user experience and can be penalized by search engines. Fix: Write natural, descriptive text that accurately represents the image.
- Using vague or unhelpful descriptions: → Descriptions like "image123.jpg" or "screenshot" provide zero value. Fix: Be specific. "Screenshot of the Bilarna dashboard showing vendor comparison filters" is useful.
- Starting with "image of" or "graphic of": → Screen readers already announce the element as an image, making this phrase redundant. Fix: Start with the descriptive content directly.
- Writing overly long paragraphs: → Long alt text is disruptive when read by a screen reader. Fix: Be succinct. If more description is needed, provide it in the page text or via a `longdesc` attribute/link.
- Neglecting context: → Describing what is literally in the image without considering the page context misses its function. Fix: Ask, "What information does this image convey *on this specific page*?"
- Forgetting functional images: → Describing the icon instead of the action for a button or link (e.g., "blue arrow" instead of "Submit application"). Fix: Describe the action that will occur.
- Relying solely on automation: → Auto-generated alt text from AI tools is often inaccurate or misses nuance. Fix: Use automation as a first draft or for simple images, but always have a human review and edit.
In short: Avoid alt text that is missing, spammy, vague, redundant, too long, context-blind, or fully automated.
Tools and resources
Choosing the right mix of tools is critical to efficiently implementing alt text at scale without sacrificing quality.
- Automated Accessibility Scanners — Use these for the initial audit and ongoing monitoring. They quickly identify images missing alt attributes across your site but cannot assess the quality of the descriptions.
- Browser Developer Tools — Use these for manual, page-by-page inspection. You can easily view the alt text for every image on a live page to perform spot checks.
- SEO Platform Audit Modules — Use these to understand the SEO impact. Many SEO tools include site crawlers that flag missing or duplicate alt text as technical issues affecting search performance.
- Content Management System (CMS) Plugins — Use these to enforce workflows. Plugins can remind editors to add alt text, suggest AI-generated descriptions, or make the alt text field mandatory before publishing.
- AI-Based Image Description Services — Use these for generating a first draft at scale, especially for large legacy image libraries. They provide a baseline that must be reviewed and refined by a human for accuracy and context.
- Screen Reader Software — Use this for final quality assurance. Testing your pages with a free screen reader like NVDA or VoiceOver is the most direct way to experience how your alt text will be consumed.
- Accessibility Guideline References — Use these for foundational knowledge. The WCAG (Web Content Accessibility Guidelines) Success Criterion 1.1.1 is the definitive standard for non-text content requirements.
- Specialized Accessibility Consultancies — Use these for expert audits, training, and complex projects. They provide the deep expertise needed for compliance and advanced implementation.
In short: Combine audit scanners, CMS tools, AI draft generators, and manual testing to create an efficient and effective alt text process.
How Bilarna can help
Finding and vetting specialized providers for accessibility and SEO services, like comprehensive alt text remediation, is time-consuming and fraught with uncertainty.
Bilarna is an AI-powered B2B marketplace that connects businesses with verified software and service providers. If your project requires external expertise—whether it's a full-scale accessibility audit, a CMS plugin development to streamline alt text entry, or training for your team—Bilarna's platform can help you identify qualified partners.
Our matching system considers your specific project requirements, budget, and timeline to surface relevant providers who have been verified through our programme. This allows founders, marketing managers, and procurement leads to efficiently compare options and make informed decisions to address their alt text and broader digital compliance challenges.
Frequently asked questions
Q: How long should alt text be?
Aim for concise descriptions, typically under 125 characters. This is enough for most images and ensures screen readers can deliver the information efficiently. The priority is accuracy and context, not length. For complex images, provide a short summary in the alt attribute and a full description elsewhere on the page.
Q: Should every single image have alt text?
Every image must have an `alt` attribute in the HTML code. However, purely decorative images that provide no informational value should have an empty attribute (`alt=""`). This instructs assistive technologies to skip them, improving the user experience. Informative and functional images must always have descriptive alt text.
Q: Can I use AI to generate all my alt text automatically?
AI is a useful tool for generating initial drafts, especially for large archives, but it is not a complete solution. AI can misidentify objects, miss critical context, and fail to understand an image's function on the page. The best practice is to use AI for scale and then have a human editor review and correct every description for accuracy and relevance.
Q: Does alt text really impact my website's SEO?
Yes, directly and indirectly. Directly, descriptive alt text helps your images rank in Google Image Search, driving traffic. Indirectly, it provides semantic context to search engines about your page's content, contributing to overall topical understanding and quality signals, which can influence rankings. It is a core technical SEO factor.
Q: What's the difference between alt text and an image caption?
Alt text is a hidden attribute read by screen readers and search engines. A caption is visible on the page for all users, often to add commentary, attribution, or explanation. They serve different purposes. An image can have both: the alt text describes the base content, and the caption provides additional context.
Q: How do I handle alt text for infographics or complex data visualizations?
Use a two-part approach:
- In the `alt` attribute, provide a brief summary of the infographic's main conclusion or subject (e.g., "Bar chart showing Q3 revenue growth across European markets").
- Then, provide the full data and detailed explanation in text directly on the page immediately following the graphic, or link to a accessible data table.