How to Check If Your Images Have Alt Text

Missing image alternative text is a common website audit finding, but filling every empty field with keywords is not a repair. Alternative text communicates the purpose of an image when its visual information is not available to a reader, including people using screen readers. Sometimes the right text is a short description of useful information; sometimes the correct value is deliberately empty because the image is decorative. A reliable audit distinguishes these situations, checks the rendered page and repairs the content management process that allowed avoidable errors to accumulate. This guide explains how an agency or site owner can work through that decision without substituting automated guesses for accessibility judgement.

Understand what an alt attribute actually does

In HTML, an image's alt attribute provides a text alternative appropriate to the image's role. The browser may use it when the image is unavailable, and assistive technology can expose it to people who cannot perceive the image. It should communicate the essential information or function, not necessarily enumerate every visible object. A useful description is contextual: the same photograph can require different text if it illustrates a staff member, documents a product defect or simply adds atmosphere.

For a decorative image that contributes no additional information, an empty alt attribute can be correct. This differs from an image with no alt attribute at all, which may leave accessibility behaviour uncertain. Consult the W3C WAI Images Tutorial when deciding among informative, functional, decorative and complex images. Search engines can also use alt text to understand images, but accessibility and truthfulness should take priority over manufactured keyword density.

Identify which images require meaningful text

Start by looking at how each image is used on its actual page. A product image showing a distinctive component can need a description of that component. A screenshot containing steps or error messages should convey the information needed to follow the instructions. A staff photograph adjacent to a named biography may need the person's name or role if it adds meaningful identity, but should not invent credentials. A decorative wave behind a heading usually needs no spoken description.

Ask whether removing the image would remove information or make an action harder to understand. If yes, provide an equivalent alternative or a fuller explanation in nearby text. If no, consider a decorative treatment. Resist writing 'image of' or 'picture of' mechanically for every item: screen reader users generally already know that the element is an image. Keep the wording aligned with the page's purpose.

Pay special attention to linked and functional images

An image used as a link or button serves a functional role. Its alternative name should describe what activating it does rather than merely what the graphic depicts. A magnifying-glass icon that triggers search needs an accessible name such as 'Search the site'. A linked company logo may appropriately identify the home page destination. A shopping-basket icon should not have only the alt value 'basket' if the intended action is to open the cart.

Check the complete control, including any adjacent text and ARIA label, before deciding whether the image itself needs an alt phrase. Duplicate spoken names can be frustrating. Avoid using alternative text as an invisible place to cram SEO terms. Verify keyboard activation, focus and the destination of linked images along with the accessible label; a correct alt string cannot fix a broken control.

Give charts and screenshots sufficient explanation

Complex diagrams often cannot be explained adequately in a short alt attribute alone. Provide a brief identifying alternative and explain the meaningful relationships or data in nearby text or an accessible data table. A chart comparing monthly enquiries should state the main observation and give underlying figures in a form a reader can inspect, rather than saying only 'growth chart'. Do not invent a trend or percentage not present in the source.

For a screenshot in a tutorial, describe the interface region or critical setting that the reader must find. If the screenshot displays personal details, redact them before publishing. Keep instructions robust to interface changes by including written navigation steps; an image on its own may become outdated or inaccessible. Cite the creator and licence where the image is not owned by the publishing organisation, without assuming that a publicly viewable image is free to reuse.

Audit the rendered website, not just a media library field

Content management systems may store alternative text in media records, custom fields, templates or inline HTML. A media library description can be present while a theme ignores it, or an image can be reused in contexts that call for different alternatives. Inspect the rendered page and the actual img element. Check representative templates, including articles, landing pages, product cards, image galleries, banners and navigation controls.

Automated accessibility tools can identify missing attributes, suspicious patterns and some empty controls. They cannot reliably decide whether the description conveys the right meaning for a reader. Combine a site scan with manual review and screen reader testing where appropriate. Make a small issue register recording page, element, image role, actual output, recommended change and owner. This converts a vague audit finding into actionable work.

Avoid keyword stuffing and generic machine descriptions

Alt text should not be a list of unrelated locations, products and search phrases. 'SEO agency London marketing services best ranking consultant' is not a meaningful alternative for a screenshot of a settings menu. Likewise, a generic AI-generated phrase such as 'a beautiful dynamic image showing success' communicates little. Describe what the image is doing on the page. Where subject-matter detail matters, ask the editor or service owner to verify it.

Image recognition tools can suggest draft descriptions for large inventories, but they may misidentify people, equipment, diagrams or text. Review every consequential description, especially for product instructions, healthcare, finance or safety-related material. Never imply that automation has inspected content or verified rights when it has not. Google Search Central's image SEO documentation recommends descriptive, contextually useful alt text, not padding.

Choose where the correction belongs

If one article image has inadequate alt text, edit that instance in its proper context. If an entire template outputs img elements without the correct attribute, repair the shared component. If editors repeatedly leave meaningful images undescribed, add an editorial prompt and training to the publishing workflow. A template-level correction can protect hundreds of future pages, but it must not assign identical generic text to images with different purposes.

Some decorative images are better delivered through CSS rather than semantic content. Do not blindly move important images into CSS backgrounds, because that can remove them from the accessible document. Check the original content requirement, the source of truth and who owns the fix. For an agency handover, document examples of informative, decorative and functional images so future content editors can make consistent decisions.

Validate accessibility and technical implementation

After the fix, test the public page using the keyboard, appropriate assistive technology and HTML inspection. Confirm that meaningful images are described, decorative images are ignored, functional controls have usable names and complex figures have sufficient nearby explanation. Test on mobile as well as desktop. For multilingual pages, use language-appropriate descriptions and avoid copying English text into unrelated translations.

Record what was checked and any exceptions. A missing-alt warning may be straightforward, but neither a clean automated scan nor a full set of nonempty alt strings proves complete accessibility. Some images should be silent, and a verbose inaccurate description can be worse than a concise correct one. The correct outcome is an equivalent user experience, not a maximal number of attributes.

Keep image governance part of normal publishing

Include a short image review in the editorial checklist: purpose, context, alternative text, source permission, caption and mobile behaviour. Audit key templates after site redesigns and plugin updates. When new staff take over content, share examples and explain why decorative images differ from informative ones. A sustained publishing process reduces the need for repetitive bulk repairs.

For primary references see W3C's alternative-text decision tree, WAI Images Tutorial and Google's image SEO best practices. These sources support accessible and descriptive image handling, not promises about a particular page's search ranking.