How to Write Image Alt Text for Better SEO
Table of Contents
Every image you publish on your website serves two audiences. The first is your visitors, who rely on images to reinforce information, demonstrate products, explain concepts or make content more engaging. The second is search engines, which use a combination of signals to understand what an image represents and how it relates to the rest of the page. Writing effective image alt text helps both audiences by making visual content more accessible while providing useful context for search engines.
One of the biggest misconceptions in SEO is that alt text exists purely as another place to insert keywords. While including relevant keywords can be beneficial when they naturally describe the image, the primary purpose of the HTML alt attribute has always been accessibility. Screen readers use alt text to describe images to people with visual impairments, and browsers display it when an image cannot be loaded. Google also recommends descriptive alt text because it helps its systems better understand image content, but it is only one of many signals used for image indexing and ranking.
Modern search engines are far more sophisticated than they were a decade ago. They analyse the surrounding page content, headings, image filenames, captions and even the image itself using computer vision. This means writing natural, descriptive alt text is far more effective than stuffing every image with target keywords. In many cases, a concise description that accurately reflects the image will perform better for both accessibility and SEO than an overly optimised alternative.
In this guide, you’ll learn what image alt text is, why it still matters for SEO in 2026, how search engines interpret images, and the practical rules for writing effective descriptions. We’ll also cover common mistakes to avoid, when decorative images should use empty alt attributes, how AI can help generate alt text responsibly, and how to audit your website to identify opportunities for improvement.
What Is Image Alt Text?
Image alt text, short for alternative text, is a description added to an image using the HTML alt attribute. Its primary purpose is to communicate the meaning or content of an image to people who cannot see it, making websites more accessible while also providing useful context for search engines.
A typical HTML image looks like this:
<img src=”red-running-shoes.jpg” alt=”Red trail running shoes with black soles”>
In this example, the text inside the alt attribute describes the image rather than the filename. If the image cannot be displayed or a visitor is using assistive technology, this description becomes the primary way of understanding what the image represents.
How Screen Readers Use Alt Text
Screen readers are used by people with visual impairments to navigate websites. When a screen reader encounters an image, it reads the contents of the alt attribute aloud. Without meaningful alt text, users may hear only that an image exists—or, in some cases, hear an unhelpful filename such as IMG_4827.jpg.
For informative images, well-written alt text provides valuable context that sighted users gain visually. For example, instead of hearing “image”, a user might hear “Technician installing a fibre broadband router in an office.” This allows everyone to understand the content and purpose of the image regardless of how they access the website.
What Happens When Images Fail to Load?
Although modern internet connections are generally reliable, images can still fail to load because of network issues, browser settings or broken image links. In these situations, browsers often display the alt text instead of the image.
This fallback ensures users can still understand the content even when the visual element is unavailable. For ecommerce websites, for example, descriptive alt text can help visitors identify products if product images fail to display.
Why Search Engines Use Alt Text
Search engines cannot interpret images in exactly the same way humans do. While advances in AI and computer vision have significantly improved image recognition, search engines still rely on contextual signals to understand visual content accurately.
Alt text is one of those signals. Alongside surrounding copy, headings, captions, structured data and descriptive filenames, it helps search engines determine what an image contains and how it relates to the page. This information can improve image indexing and increase the likelihood of appearing in Google Images and other visual search results.
It’s important to remember that alt text is not a place to force keywords into every image. Instead, it should describe the image naturally and accurately. When the description genuinely reflects both the image and the surrounding content, it supports accessibility and SEO at the same time.
Ultimately, the best alt text serves people first. By making images understandable to all users, you’re also giving search engines clearer information about your content—a rare example where accessibility and SEO work hand in hand.
Does Alt Text Still Matter for SEO?
The short answer is yes—but not for the reasons many people assume.
Years ago, alt text was often treated as another place to insert target keywords in the hope of improving rankings. While search engines did rely more heavily on metadata at the time, Google’s image recognition capabilities have evolved significantly. Today, Google analyses images using a combination of computer vision, machine learning and page-level context, meaning alt text is no longer the sole indicator of what an image contains.
That doesn’t mean alt text has become less important. Instead, its role has changed. Rather than acting as a standalone ranking factor, it forms part of a broader set of signals that help Google understand the purpose and relevance of an image.
Google’s Understanding of Images Has Improved
Modern search engines can recognise many objects, scenes and even text within images. They can identify products, landmarks, food, people and other visual elements with impressive accuracy. However, automated image recognition isn’t perfect, particularly when an image contains technical products, industry-specific diagrams, charts or concepts that require additional context.
This is where descriptive alt text still provides value. It confirms what the image represents and helps Google connect it to the topic of the page.
For example, a photograph of a pressure vessel head could be recognised as a large metal object by computer vision. However, well-written alt text such as “2:1 semi-ellipsoidal dished end for high-pressure vessels” gives Google much more precise information about the image and its relevance to the surrounding content.
Page Context Matters More Than Ever
One of the biggest changes in image SEO is that Google no longer evaluates images in isolation. Instead, it considers how the image fits within the rest of the page.
When determining what an image represents, Google may analyse:
- The page title
- Headings
- Nearby paragraphs
- Image captions
- Image filenames
- Structured data
- Internal linking
- Overall page topic
Alt text works alongside these signals rather than replacing them. If your page is about mountain bikes, for example, an image described as “Full-suspension trail mountain bike on a forest trail” reinforces the page’s topic. Conversely, keyword-stuffed alt text that bears little relation to the surrounding content provides little value for either users or search engines.
Alt Text Can Improve Visibility in Google Images
Google Images has become an important source of organic traffic, particularly for ecommerce websites, publishers and businesses that rely on visual content. Product photos, infographics, diagrams and original photography all have the potential to appear in image search results.
Optimised alt text helps Google understand these images, increasing the chances that they are indexed correctly and shown for relevant searches. However, success in Google Images also depends on other factors such as image quality, page authority, descriptive filenames, loading performance and the relevance of the surrounding content.
Alt text should therefore be viewed as one part of a complete image SEO strategy rather than a standalone optimisation.
What Google Recommends
Google’s own Search Central documentation advises website owners to write descriptive, information-rich alt text that explains the content of an image naturally. It also recommends avoiding keyword stuffing and ensuring that images are placed near relevant text on the page.
Google further advises using descriptive filenames, providing high-quality images and making sure visual content supports the overall topic of the page. Together, these practices help Google’s systems better understand both individual images and the pages they appear on.
The Bottom Line
Alt text still matters for SEO in 2026 because it provides context that automated image recognition cannot always infer on its own. More importantly, it improves accessibility, which is its primary purpose.
The most effective approach is to write alt text that accurately describes the image, fits naturally within the page’s context and genuinely helps users understand the content. When you do that, you’re following accessibility best practices while also giving search engines clearer signals about your images—an approach that is far more sustainable than chasing outdated keyword optimisation techniques.
How Search Engines Understand Images
One of the biggest misconceptions about image SEO is that search engines rely almost entirely on the alt attribute to understand an image. While alt text remains an important signal, Google’s systems analyse images using a much broader combination of contextual, technical and visual information.
Think of image understanding as a puzzle. Alt text is one piece, but search engines combine multiple signals to build a much clearer picture of what an image represents and whether it is relevant to a user’s search.
Alt Text Provides Direct Context
Alt text is the most explicit description you can provide for an image. It tells search engines—and assistive technologies—what the image is intended to represent.
For example, these two descriptions communicate very different levels of information:
Poor alt text
alt=”image”
Better alt text
alt=”Technician installing a fibre broadband router in a modern office”
The second example gives both users and search engines meaningful context while remaining natural and descriptive.
Surrounding Copy Reinforces Meaning
Google doesn’t evaluate images in isolation. The paragraphs immediately before and after an image help explain why it has been included on the page.
Imagine an article explaining how to install solar panels. If the surrounding copy discusses roof mounting systems, electrical connections and installation safety, Google can use this text to better understand an accompanying photograph.
When the written content and the image support each other, both become stronger SEO signals.
Headings Establish the Topic
Page headings create a hierarchy that helps search engines understand what each section is about.
If an image appears beneath a heading such as “Installing Composite Decking Boards”, Google already has valuable context before it even analyses the image itself.
An image with descriptive alt text placed beneath a relevant heading is far easier for search engines to interpret than the same image placed in an unrelated section.
Captions Add Valuable Context
Image captions are often overlooked, but they provide another layer of explanation.
Unlike alt text, which primarily serves accessibility, captions are visible to all visitors. Because users frequently read captions when scanning a page, search engines also consider them when interpreting image relevance.
For example:
Caption
“Heat pump installation completed on a detached property in Yorkshire.”
This reinforces both the image content and the page topic without repeating the alt text word for word.
Image Filenames Matter More Than Many People Realise
Uploading images with filenames like:
IMG_4837.jpg
provides almost no useful information.
A descriptive filename such as:
air-source-heat-pump-installation.jpg
helps search engines understand the image before they even process the page.
While filenames alone won’t dramatically improve rankings, they contribute to Google’s overall understanding of the image and are considered a recognised image SEO best practice.
Structured Data Adds Semantic Information
Structured data doesn’t describe every image directly, but it helps search engines understand the relationship between images and the content they support.
For example:
- Product Schema identifies product photographs.
- Recipe Schema highlights recipe images.
- Article Schema associates featured images with editorial content.
- Local Business Schema connects images with a business location.
When combined with descriptive alt text and relevant page content, structured data provides additional confidence about what an image represents.
The Overall Page Topic Is the Strongest Signal
Perhaps the most important factor is the subject of the page itself.
An image of a mountain bike on a page reviewing trail bikes is interpreted very differently from the same image on a page about outdoor photography. Google analyses the overall purpose of the page, its headings, internal links and supporting content to determine how each image contributes to that topic.
This is why generic stock images often provide limited SEO value—they rarely add meaningful information that supports the page’s primary subject.
Computer Vision Completes the Picture
In addition to analysing text, Google uses advanced computer vision and machine learning to recognise objects, colours, landmarks, products and even text contained within images.
However, AI cannot always understand intent or specialist terminology. For example, it may recognise an industrial component as a piece of metal but not identify it as a 2:1 semi-ellipsoidal dished end for a pressure vessel. That’s where descriptive alt text and relevant page context become invaluable.
Bringing It All Together
Rather than relying on a single attribute, search engines combine multiple signals to understand images accurately. The strongest image SEO comes from ensuring all of these elements work together:
- Descriptive, user-focused alt text
- Relevant surrounding copy
- Clear heading structure
- Helpful image captions where appropriate
- Descriptive image filenames
- Appropriate structured data
- A page with a clear, focused topic
When every signal points in the same direction, search engines can understand your images with greater confidence, improving their chances of appearing in relevant search results while also creating a better experience for users.
How to Write Good Alt Text
Writing effective alt text isn’t about finding the perfect formula or squeezing in as many keywords as possible. It’s about providing enough information for someone who can’t see the image to understand its purpose while also giving search engines useful context.
The best alt text feels natural because it describes what actually matters in the image and how that image relates to the surrounding content.
Describe What Matters
Not every detail in an image is equally important. Focus on the information that supports the page’s purpose rather than trying to describe every visible element.
For example, if you’re writing a blog about electric vehicles, an image of a charging point doesn’t need to describe the weather, nearby buildings or the colour of the pavement.
Poor
alt=”Car parked outside on a sunny day”
Better
alt=”Electric vehicle charging at a public rapid charging station”
The second example describes the subject that is relevant to the article rather than unnecessary background details.
Write Naturally
Alt text should read like a short sentence written for a person. Avoid awkward keyword repetition or unnatural phrasing simply because you’re trying to optimise for SEO.
Poor
alt=”SEO agency SEO services SEO company digital marketing”
Better
alt=”Digital marketing team reviewing SEO performance in Google Analytics”
The improved version is easier for users to understand while still providing relevant context for search engines.
Keep It Concise
Most images can be described clearly in one short sentence. While there is no official character limit, concise descriptions are generally easier for screen reader users and more effective than lengthy explanations.
Aim to include the important information without turning the alt text into a paragraph.
Poor
alt=”A man wearing a blue shirt standing in a large office with several computer monitors, white desks, plants in the background and a large window overlooking the city while discussing website performance with colleagues.”
Better
alt=”SEO consultant reviewing website performance with colleagues”
The shorter version communicates the image’s purpose without unnecessary detail.
Include Keywords Only When They’re Relevant
If your target keyword genuinely describes the image, include it naturally. If it doesn’t, leave it out.
Forcing keywords into every image can reduce accessibility and offers little SEO benefit.
Imagine you’re writing an article targeting image alt text.
If the image shows HTML code, this works well:
Good
alt=”Example of HTML image alt text in a webpage”
However, using the keyword on an unrelated image makes little sense.
Poor
alt=”Image alt text SEO laptop coffee office digital marketing”
Keywords should support the description, not dominate it.
Avoid Starting with “Image of” or “Picture of”
Screen readers already announce that an element is an image, so phrases such as “image of” or “picture of” usually repeat information the user already knows.
Instead, begin directly with the subject.
Poor
alt=”Image of a mountain bike on a woodland trail”
Better
alt=”Full-suspension mountain bike on a woodland trail”
This creates a cleaner experience for assistive technology users while making the description more concise.
Consider the Page Context
The same image may require different alt text depending on the page where it appears.
Imagine using the same photograph of a mountain bike:
On a product page:
alt=”Carbon fibre trail mountain bike with 160 mm suspension”
On a travel guide:
alt=”Mountain bike riding through Dalby Forest trail centre”
On a maintenance article:
alt=”Rear mountain bike suspension linkage requiring lubrication”
The image hasn’t changed, but its purpose has. Effective alt text describes the role the image plays within the page, not just what it physically contains.
Good vs Bad Alt Text Examples
Image | Poor Alt Text | Better Alt Text |
Product photo | alt=”product” | alt=”Stainless steel insulated water bottle with bamboo lid” |
Team photo | alt=”staff” | alt=”Digital marketing team discussing campaign performance” |
Blog illustration | alt=”SEO SEO SEO image optimisation” | alt=”Diagram showing how search engines interpret image alt text” |
Ecommerce image | alt=”IMG_2456″ | alt=”Grey fabric corner sofa with oak legs” |
Local business | alt=”Building” | alt=”Front entrance of a dental practice in Leeds” |
A Simple Rule to Remember
Before publishing an image, ask yourself one question:
“If someone couldn’t see this image, would this description help them understand why it’s here?”
If the answer is yes, you’ve probably written good alt text.
By focusing on clarity, relevance and accessibility first, you’ll naturally produce alt text that also supports SEO. That’s because modern search engines reward content that genuinely helps users understand a page—not content that simply repeats keywords.
When Images Should Not Have Alt Text
One of the most common misconceptions about accessibility is that every image needs descriptive alt text. In reality, some images should have no descriptive alt text at all. Knowing the difference is just as important as knowing how to write good descriptions.
If an image doesn’t add information, provide meaning or help users understand the content, it usually shouldn’t be described. Instead, it should use an empty alt attribute (alt=””), allowing screen readers to ignore it completely.
Decorative Images
Decorative images exist purely to improve the visual appearance of a page. They don’t contribute any information that a visitor would miss if the image disappeared.
Examples include:
- Background textures
- Abstract design elements
- Decorative icons
- Dividers
- Shadows and flourishes
- Hero background graphics that don’t convey information
These images should use an empty alt attribute:
<img src=”blue-wave-background.svg” alt=””>
This tells assistive technologies that the image can safely be skipped, making the browsing experience cleaner and less distracting.
Spacer Images
Although spacer images were once commonly used for page layouts, modern websites should achieve spacing using CSS instead.
If you’re maintaining an older website that still uses transparent GIFs or similar spacer images, they should also use an empty alt attribute.
For example:
<img src=”spacer.gif” alt=””>
Without an empty alt attribute, screen readers may announce unnecessary elements, interrupting the user’s flow through the page.
Purely Stylistic Graphics
Many websites include graphics that reinforce branding or visual design without adding meaningful content.
Examples include:
- Decorative arrows
- Background patterns
- Animated shapes
- Colour accents
- Non-informative illustrations
If removing the image wouldn’t change the user’s understanding of the page, it should generally be treated as decorative.
For example, a decorative arrow beside a heading doesn’t need:
alt=”Blue arrow”
Instead:
alt=””
The user already understands the heading without needing the arrow described.
Understanding: alt=””
An empty alt attribute is not the same as omitting the alt attribute altogether.
This distinction is important.
Correct
<img src=”background-pattern.svg” alt=””>
This explicitly tells screen readers to ignore the image.
Incorrect
<img src=”background-pattern.svg”>
When the alt attribute is missing entirely, assistive technologies may attempt to interpret the image, announce its filename or indicate that an unlabeled image exists. This creates unnecessary noise for users relying on screen readers.
A Simple Decision Framework
When adding an image to a page, ask yourself these questions:
- Does this image communicate information that isn’t already available in nearby text?
- Yes: Write descriptive alt text.
- No: Continue.
- Is the image purely decorative or used only for layout or styling?
- Yes: Use alt=””.
- No: Continue.
- Would someone using a screen reader miss important information if this image wasn’t described?
- Yes: Write meaningful alt text.
- No: Use alt=””.
Making this distinction keeps websites more accessible, reduces unnecessary interruptions for screen reader users and aligns with both accessibility standards and Google’s guidance. The goal isn’t to describe every image—it’s to describe every image that matters.
Common Alt Text Mistakes
Writing alt text is relatively straightforward once you understand its purpose, yet many websites still make the same mistakes. Some reduce accessibility for users, while others provide little or no SEO value. Fortunately, they’re also some of the easiest issues to identify and fix during a website audit.
Keyword Stuffing
One of the oldest SEO habits is cramming as many keywords as possible into the alt attribute.
For example:
Poor
alt=”SEO agency SEO company SEO services digital marketing website design Leeds”
This doesn’t accurately describe an image and creates a poor experience for screen reader users.
A better approach is to describe the image naturally.
Better
alt=”Digital marketing team reviewing SEO campaign performance”
If your target keyword genuinely fits the image, include it once. If it doesn’t, don’t force it.
Repeating Page Titles
Some content management systems automatically populate alt text using the page title or product title. While this may seem convenient, it often results in descriptions that tell users nothing about the image itself.
Imagine a page titled:
How to Write Image Alt Text
Every image on the page doesn’t need:
alt=”How to Write Image Alt Text”
Instead, describe what each individual image shows.
For example:
alt=”Diagram explaining how search engines interpret image alt text”
The page title already tells users what the article is about. The alt text should explain the image.
Using Generic Descriptions
Descriptions such as:
- image
- photo
- graphic
- picture
- logo
provide almost no useful information.
Imagine browsing an ecommerce website using a screen reader and hearing:
“Image.”
That tells the user nothing.
Instead, write descriptions that communicate meaningful information.
Poor
alt=”Product”
Better
alt=”Black leather office chair with adjustable headrest”
Specific descriptions help both users and search engines understand the content.
Missing Alt Text
A missing alt attribute is different from an empty one.
For informative images, leaving the attribute out entirely can cause assistive technologies to announce filenames or simply identify the image as unlabeled.
Incorrect:
<img src=”team-photo.jpg”>
Correct:
<img src=”team-photo.jpg” alt=”Customer support team answering calls in the office”>
For decorative images, the correct approach is:
<img src=”background-shape.svg” alt=””>
Always include the alt attribute, even if it’s intentionally empty.
Writing Essays
Alt text should describe an image—not tell the entire story behind it.
Some AI tools and accessibility plugins generate descriptions that are far longer than necessary.
For example:
Poor
alt=”A woman sitting at a large oak desk in a modern office with several computer monitors, notebooks, coffee cups, indoor plants, colleagues working in the background and large windows allowing natural light into the building while discussing quarterly marketing performance.”
Most of this detail isn’t needed.
A more effective description would be:
alt=”Marketing manager reviewing quarterly performance with colleagues”
Concise descriptions are easier for screen reader users to understand while still providing useful context.
Copying Filenames
Many websites accidentally use image filenames as alt text, particularly after automated imports or CMS migrations.
Examples include:
alt=”IMG_4827.jpg”
or
alt=”stock-photo-final-v4.webp”
These filenames make sense to computers but not to people.
A descriptive alternative would be:
alt=”Solar panels installed on the roof of a detached house”
Even if you use descriptive filenames for SEO, they should never replace meaningful alt text.
A Quick Self-Check Before Publishing
Before uploading an image, ask yourself five simple questions:
- Does the alt text accurately describe the image?
- Would someone using a screen reader understand why the image is included?
- Is the description concise and natural?
- Have I avoided unnecessary keyword repetition?
- Does the description add information rather than repeat nearby text?
If you can answer yes to all five, your alt text is likely serving both accessibility and SEO effectively.
The goal isn’t to optimise every image for search engines. It’s to make every meaningful image understandable for users. When you achieve that, you’re also giving search engines the context they need to interpret your visual content more accurately.
Can AI Write Alt Text?
AI has become remarkably good at recognising the contents of images. Modern image recognition models can identify people, objects, locations, products and even text within images, making them an attractive option for generating alt text at scale.
For organisations managing thousands of images, AI can significantly reduce the time required to create descriptions. However, while AI is an excellent starting point, it should rarely be considered the final version. Effective alt text depends not only on recognising what’s in an image but also on understanding why that image appears on a particular page.
Where AI Performs Well
For many websites, AI can improve accessibility simply by replacing missing alt text with descriptive alternatives. This is particularly useful for large ecommerce catalogues, media libraries and websites containing thousands of existing images.
Some of AI’s biggest advantages include:
- Speed – AI can generate descriptions for thousands of images in minutes rather than weeks.
- Consistency – It applies the same formatting and writing style across large collections of images.
- Scalability – Large ecommerce stores, publishers and enterprise websites can audit and improve vast image libraries much more efficiently.
- Good object recognition – Modern AI models are increasingly accurate at identifying common products, animals, buildings, landscapes and everyday scenes.
For organisations that previously had no alt text at all, AI can represent a significant improvement over leaving images undescribed.
Where AI Falls Short
Despite rapid improvements, AI still lacks one important advantage that humans have: context.
An AI model may correctly identify what appears in an image without understanding why it matters within the page.
For example, imagine the same photograph of a laptop.
An AI tool might generate:
“Person using a laptop at a desk.”
Technically, that’s accurate.
However, depending on the page, a human might write:
- SEO consultant analysing Google Search Console performance
- Customer completing an online insurance application
- Developer testing website accessibility
- Student attending an online coding course
The image hasn’t changed, but its purpose has. Understanding that purpose requires knowledge of the surrounding content, which AI doesn’t always interpret correctly.
Generic Descriptions
AI-generated alt text often plays it safe by producing broad descriptions.
For example:
“Person smiling indoors.”
or
“Building with windows.”
While technically correct, descriptions like these rarely provide enough context to help users fully understand the image or support the topic of the page.
Human editors can add the specificity that AI frequently misses.
Accessibility Considerations
Accessibility isn’t simply about describing visible objects.
Good alt text communicates the information that someone would miss if they couldn’t see the image.
For example, a graph showing website traffic growth shouldn’t receive:
“Blue line chart.”
A better description might be:
“Line chart showing a 42% increase in organic traffic over six months.”
Likewise, a product image may need to highlight a feature that matters to the customer rather than simply listing visible objects.
This ability to identify the most important information is something AI still struggles with in many situations.
Specialist and Technical Content
AI also finds specialist industries more challenging.
An industrial engineer may immediately recognise a pressure vessel component, while an AI model might simply describe it as:
“Large metal bowl.”
Likewise, legal diagrams, medical illustrations, engineering drawings and scientific imagery often require terminology that general-purpose AI models cannot consistently identify.
In these cases, human expertise remains essential.
The Best Approach Is AI-Assisted, Human-Reviewed
Rather than choosing between AI and manual writing, most organisations will benefit from combining both.
A practical workflow looks like this:
- Generate an initial description using AI.
- Review it alongside the surrounding page content.
- Check that it accurately reflects the purpose of the image.
- Remove unnecessary wording.
- Add relevant context where appropriate.
This approach delivers much of AI’s speed while maintaining the quality expected for accessibility and SEO.
The Bottom Line
AI is an excellent tool for generating first drafts of alt text, especially for large websites with thousands of images. It can improve consistency, reduce workload and help identify images that currently have no descriptions at all.
However, AI cannot reliably understand editorial intent, business context or the specific reason an image appears on a page. Human review remains essential to ensure alt text is accurate, meaningful and genuinely useful for people using assistive technologies.
The most effective alt text is rarely written by AI alone. It’s created through a combination of automated assistance and human judgement, producing descriptions that serve users first while also giving search engines clearer, more reliable information about your visual content.
How to Audit Your Website’s Alt Text
Writing good alt text for new content is important, but many websites already contain hundreds or even thousands of existing images. Over time, it’s common for alt text to become inconsistent, duplicated or missing altogether, particularly after website redesigns, CMS migrations or bulk product imports.
A structured audit helps you identify the most significant issues first, allowing you to improve both accessibility and image SEO without manually checking every page.
1. Crawl Your Website
The first step is to crawl your website and extract information about every image.
Most website crawlers can identify:
- Images missing an alt attribute
- Empty alt attributes
- Duplicate alt text
- Image filenames
- Image locations
- Page URLs
This gives you a complete inventory of image accessibility issues across the site and highlights pages that require further review.
2. Identify Missing Alt Text
Missing alt text is usually the highest-priority issue, particularly for informative images.
Review each missing attribute individually and ask:
- Is this image informative?
- Does it add meaning to the page?
- Would someone using a screen reader miss important information if it wasn’t described?
If the answer is yes, write descriptive alt text.
If the image is purely decorative, add an empty attribute (alt=””) instead of leaving the attribute out completely.
3. Look for Duplicate Alt Text
Duplicate alt text often appears after bulk imports or when content management systems automatically reuse product names or page titles.
For example, you might discover dozens of images using identical descriptions such as:
“Product image”
or
“Company logo”
Some duplication is perfectly acceptable—for example, the same logo appearing across multiple pages. However, informative images should usually have descriptions that reflect their individual purpose within each page.
Large numbers of duplicated descriptions are often a sign that alt text has been generated automatically rather than written with context in mind.
4. Check for Keyword Stuffing
Older websites sometimes contain alt text written purely for SEO rather than accessibility.
Look for descriptions that:
- Repeat keywords multiple times
- List services instead of describing images
- Contain unnaturally long strings of keywords
- Don’t accurately reflect what the image shows
If the description sounds awkward when read aloud, it’s probably trying too hard to target search engines instead of helping users.
Modern SEO rewards natural, descriptive alt text far more than keyword repetition.
5. Prioritise Your Most Important Pages
Not every image needs immediate attention.
Start with the pages that have the greatest impact on your business, such as:
- Homepage
- Service pages
- Product pages
- Category pages
- Landing pages
- High-traffic blog posts
Improving alt text on these pages is likely to deliver the greatest accessibility and SEO benefits before expanding your audit across the rest of the site.
Use an Automated Checker to Speed Up the Process
Manually reviewing every image quickly becomes impractical on larger websites. An automated auditing tool can identify missing, duplicated and potentially problematic alt text in minutes, allowing you to focus your time on improving descriptions rather than searching for issues.
The Techomatic Image Alt Text Checker scans your pages and highlights common problems, making it easier to prioritise fixes and maintain consistent image optimisation across your website. Whether you’re auditing a small business website or a large ecommerce catalogue, it provides a fast starting point for improving both accessibility and image SEO.
Make Alt Text Audits Part of Your Regular SEO Reviews
Alt text shouldn’t be treated as a one-off optimisation. New images are uploaded regularly, products change and content evolves, creating new opportunities for missing or inconsistent descriptions.
Including image accessibility within your routine technical SEO audits helps ensure new issues are identified early. Over time, these small improvements contribute to a more accessible website, clearer signals for search engines and a better experience for every visitor.
Final Thoughts
Writing effective image alt text isn’t about finding another place to insert keywords or trying to manipulate search rankings. Its primary purpose is, and always has been, to help people understand visual content when they can’t see it. When you focus on describing images clearly, accurately and in context, you’re creating a more accessible website for everyone.
Fortunately, this user-first approach also aligns with modern SEO. Search engines have become increasingly sophisticated at interpreting images, but they still rely on descriptive signals to understand how visual content relates to the rest of a page. Well-written alt text, combined with relevant headings, surrounding copy, descriptive filenames and structured data, helps reinforce that understanding.
Rather than treating alt text as a standalone SEO tactic, think of it as part of a wider strategy for creating high-quality, accessible content. Every meaningful image should contribute to the page, every description should add value and every optimisation should make the experience better for real users.
If you’d like to identify missing, duplicated or poorly written alt text across your website, try the Techomatic Image Alt Text Checker. It quickly audits your pages, highlights common issues and helps you prioritise improvements, making it easier to strengthen both your website’s accessibility and its image SEO.
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