What is "Alt Tag Usage"?
Alt tag usage, or alternative text usage, is the practice of adding descriptive text to images on a website to convey their meaning and function. This text is read by screen readers, displayed if an image fails to load, and processed by search engines to understand page content.
Ignoring alt text creates invisible barriers for users and search engines, wasting marketing spend and exposing the business to compliance risk. It's a foundational element often overlooked in the rush to publish.
- Alt Attribute (Alt Text): The HTML attribute (`alt="..."`) where the descriptive text is placed within an image tag.
- Accessibility (a11y): The primary purpose is to make visual content accessible to users who are blind, have low vision, or use assistive technologies.
- SEO Context: Search engines use alt text as a key factor for image search rankings and to better understand the topic of the surrounding page.
- Functional Images: Images that act as links or buttons (e.g., a shopping cart icon) require alt text describing the action, not the image.
- Decorative Images: Purely stylistic images that convey no meaningful information should have an empty alt attribute (`alt=""`) to be ignored by assistive tools.
- Image Context: Effective alt text depends heavily on the image's purpose within the specific page content.
- Keyword Stuffing: The harmful practice of overloading alt text with irrelevant keywords, which can hurt SEO and usability.
- Automated Alt Text: AI-generated descriptions, often provided by CMS or social platforms, which are a starting point but typically require human refinement for accuracy and context.
This topic is critical for marketing teams aiming to maximize content reach, product teams committed to inclusive design, and legal or compliance officers managing GDPR and web accessibility directive (EUWA) risks. It solves the problem of creating content that is both discoverable and universally usable.
In short: Alt tag usage is the essential practice of describing images for accessibility and search engines, directly impacting user experience, SEO, and legal compliance.
Why it matters for businesses
When businesses treat images as merely decorative, they inadvertently exclude audiences, miss search traffic opportunities, and create unnecessary legal exposure. The cost of inaction is a weaker digital presence and potential reputational damage.
- Wasted SEO Potential → Proper alt text helps images rank in search results, driving free, targeted traffic to your site and supporting overall page relevance.
- Poor User Experience for Visually Impaired Users → Without descriptions, screen reader users encounter a confusing or empty experience, alienating a significant portion of your audience.
- Increased Legal & Compliance Risk (EUWA/GDPR) → Failing to provide accessible web content, including images, can violate the European Accessibility Act and equality laws, leading to fines and lawsuits.
- Lost Conversions on Image Failures → If an image fails to load, the alt text provides context, ensuring the user still receives the intended message or call-to-action.
- Ineffective Content Marketing → Visual content is a key asset; without alt text, its value is locked away from search engines and a segment of your audience, diminishing your content ROI.
- Damaged Brand Reputation → Being perceived as a brand that doesn't prioritize inclusivity can hurt customer trust and loyalty in competitive markets.
- Inefficient Development & Content Rework → Retroactively adding alt text to hundreds of site images is a costly, manual project that could have been avoided with a simple initial process.
- Poor Performance in Voice Search & Answer Engines → As AI answer engines parse web content, descriptive alt text provides clearer semantic signals about your page's subject matter.
In short: Ignoring alt text harms accessibility, limits organic reach, and creates compliance risks, while good practice enhances user experience and supports core business goals.
Step-by-step guide
Tackling alt text for an entire website can feel overwhelming, but a systematic audit and update process makes it manageable.
Step 1: Conduct a Technical Audit
The initial obstacle is not knowing the scale of the problem. Use a crawling tool to extract a list of all images site-wide and identify which have missing, empty, or problematic alt text.
- Run a site crawl with an SEO audit platform.
- Filter the report to show all images and their corresponding alt attributes.
- Export this data to a spreadsheet for prioritization and tracking.
Step 2: Categorize Your Images
Trying to write the same type of description for every image is inefficient. Classify each image to apply the correct alt text strategy.
- Informative Images: Convey content (photos, graphs, illustrations). Require descriptive alt text.
- Functional Images: Act as links or buttons. Alt text describes the action (e.g., "submit form").
- Decorative Images: Purely for layout or visual design. Use `alt=""`.
- Complex Images: Charts, diagrams, infographics. Need a short alt text summary and a longer description elsewhere on the page.
Step 3: Write Effective Alt Text for Informative Images
The pain point is writing vague or overly literal descriptions. Good alt text is concise, contextual, and conveys the image's purpose on the page.
Imagine describing the image over the phone. Be specific but succinct. Include relevant keywords naturally if they describe the image, but avoid lists. For example, `alt="team meeting in a modern office"` is better than `alt="office"` or `alt="business team meeting collaboration success"`.
Step 4: Handle Functional and Decorative Images
A common error is leaving decorative images unlabeled or over-describing functional icons. This creates noise for screen reader users.
For a search icon button, use `alt="Search"`. For a decorative floral border, use `alt=""`. This allows assistive technology to skip irrelevant content and focus on functionality.
Step 5: Implement & Update in Your CMS
The manual process of editing HTML is unsustainable. Integrate alt text into your standard content publishing workflow.
- Ensure your CMS requires an alt text field for image uploads.
- Train content creators on the categorization and writing guidelines from Steps 2-4.
- Make the alt text field prominent in your content editor, not hidden in an "advanced" panel.
Step 6: Verify with a Screen Reader Test
You can't confirm quality without experiencing the output. A quick screen reader test validates your work from a user's perspective.
Use free built-in tools like NVDA (Windows) or VoiceOver (Mac). Navigate to a page you've updated and listen to how the images are announced. This is the ultimate "quick test" for clarity and context.
In short: Systematically audit, categorize, write context-specific descriptions, integrate into your workflow, and verify the experience with a screen reader.
Common mistakes and red flags
These pitfalls are common because alt text is often an afterthought, done hastily or automated without oversight.
- Using "Image of" or "Picture of" → This is redundant, as screen readers announce the element as an image. The pain is wasted word count. Fix it by describing the subject directly (e.g., use `alt="red sports car"` not `alt="image of a red sports car"`).
- Keyword Stuffing → Stuffing alt text with irrelevant keywords creates a poor user experience and can trigger search engine spam filters. The pain is SEO penalty and confusing audio. Fix it by writing for the user first, using keywords only if they accurately describe the image.
- Leaving Alt Attributes Empty on Informative Images (`alt=""`) → This causes screen readers to skip the image entirely, omitting critical content. The pain is information loss for users. Fix it by providing a concise description for all content-relevant images.
- Using Filenames as Default Alt Text → Filenames like `IMG_0234.jpg` are meaningless. The pain is a terrible user experience. Fix it by always writing custom, descriptive alt text during the upload process.
- Over-Describing Decorative Images → Giving detailed alt text for spacers or stylistic borders creates auditory clutter. The pain is fatigue for screen reader users. Fix it by correctly identifying decorative images and using `alt=""`.
- Neglecting Functional Image Context → Describing a button as "blue arrow" instead of "next page" fails to convey function. The pain is user confusion and inability to navigate. Fix it by describing the action, not the appearance.
- Relying Solely on AI-Generated Alt Text → Automated descriptions often miss nuance, context, or make errors. The pain is inaccuracy. Fix it by using AI output as a first draft, then a human must review and edit for accuracy and page context.
- Inconsistent Alt Text for Repeated Images → The same logo or icon described differently across pages creates a disjointed experience. The pain is brand inconsistency and confusion. Fix it by creating a small style guide for common site-wide images.
In short: Avoid redundancy, keyword spam, and missing descriptions by writing concise, contextual alt text for humans, not just for search engines.
Tools and resources
Choosing the right tool depends on whether you need to audit an existing site, enforce standards during creation, or verify compliance.
- SEO Crawling & Audit Platforms — Use these for the initial technical audit to identify all images site-wide and analyze their current alt attributes at scale.
- Accessibility Evaluation Browser Extensions — Use these for quick manual checks on individual pages to visually highlight images and their alt text status during development or content review.
- Screen Reader Software (NVDA, VoiceOver) — Use these for ultimate quality verification to experience your site as a user relying on assistive technology would.
- Content Management System (CMS) Modules/Plugins — Use these to enforce workflow by making alt text a required field, suggesting improvements, or scanning uploaded content.
- Image Asset Management Systems — Use these in large organizations to store alt text metadata directly with the image file, ensuring consistency across different web properties.
- WCAG (Web Content Accessibility Guidelines) Documentation — Use this as the definitive standard (specifically Success Criterion 1.1.1) to understand the formal requirements and testing procedures.
- AI-Based Image Description Services — Use these as a productivity aid to generate a first-draft description for batches of images, remembering human review is mandatory.
- Browser Developer Tools — Use these for on-the-spot checks by inspecting any image element to see its HTML, including the alt attribute, directly in the browser.
In short: Combine audit tools for discovery, CMS features for enforcement, and screen readers for final validation to manage alt text effectively.
How Bilarna can help
Finding and vetting agencies or specialists who can execute a thorough alt text audit and integration strategy is a time-consuming procurement challenge.
Bilarna's AI-powered B2B marketplace connects businesses with verified software and service providers specializing in web accessibility, SEO, and content strategy. You can efficiently compare providers who offer the specific audit, implementation, or training services needed to fix alt tag usage at scale.
Our platform allows you to define your project scope—whether it's a one-time site cleanup, a CMS integration project, or staff training—and receive matched recommendations from providers vetted through our verification programme. This reduces the risk and effort involved in sourcing qualified expertise.
Frequently asked questions
Q: How long should alt text be?
Alt text should be concise, typically under 125 characters. This ensures it is read comfortably by screen readers without being cut off. The key is to be as descriptive as necessary but no more. If a complex image requires more explanation, provide a short summary in the alt attribute and a longer description in the surrounding text or via a `longdesc` attribute.
Q: Do all images need alt text?
No, but all images need an *alt attribute*. This is a crucial distinction. The rule is:
- Informative/Functional Images: Need descriptive alt text.
- Decorative Images: Need an empty alt attribute (`alt=""`).
Q: Can good alt text improve my SEO?
Yes, primarily for image search. Alt text is a direct signal to search engines about the image content. While it is not a major *direct* ranking factor for general page rankings, it contributes to overall page context, accessibility (which is a Google ranking consideration), and can drive valuable traffic from image search results. Always write for the user first; SEO benefits follow.
Q: How do I handle alt text for infographics or complex charts?
This is a two-part solution. First, provide a concise summary of the main takeaway in the alt attribute (e.g., `alt="Bar chart showing a 40% increase in Q4 sales"`). Second, ensure the same data is provided in textual form on the page itself, either directly below the graphic or in a linked accessible data table. The alt text gives immediate context, the detailed text provides full understanding.
Q: Is automated alt text from my CMS or AI tool sufficient?
It is a useful starting point but rarely sufficient on its own. Automated tools often:
- Miss contextual relevance to the page.
- Make errors in identifying objects or text within images.
- Cannot determine if an image is decorative or functional.
Q: What are the legal consequences of bad alt text in the EU?
Under the European Web Accessibility Directive (transposed into national law) and the European Accessibility Act, public sector and certain private sector websites must meet accessibility standards like WCAG. Poor alt text is a direct failure of WCAG. Consequences can include:
- Formal complaints and compliance orders.
- Fines or penalties.
- Damage to brand reputation and potential loss of contracts, especially with public bodies.