10 Prompts for Writing Alt Text for SEO

Introduction (~300 words)

Ever uploaded an image to your website and left the alt text blank? You’re not alone. Many people skip this small but powerful step—until they realize how much it affects their SEO and accessibility.

Alt text (short for “alternative text”) is the hidden description that appears when an image doesn’t load. But it’s not just a backup plan. For search engines like Google, alt text is a key signal for ranking images in search results. For people using screen readers, it’s the only way to “see” what’s in the picture. Without it, your content becomes invisible to both.

Why Alt Text Matters More Than You Think

Think of alt text as a bridge. It connects your images to:

• SEO rankings – Google can’t “see” images, but it reads alt text. Well-written descriptions help your images appear in Google Images, driving more traffic to your site.
• Accessibility – Over 285 million people worldwide have visual impairments. Screen readers rely on alt text to describe images, making your content usable for everyone.
• User experience – If an image fails to load, alt text tells visitors what they’re missing. No more guessing games.

Yet, most alt text is either missing, vague, or stuffed with keywords. Common mistakes include:

• Writing “image001.jpg” (useless for SEO and accessibility)
• Overloading with keywords (“best running shoes 2024, top athletic shoes, buy running shoes online”)
• Leaving it blank (a missed opportunity for traffic and inclusivity)

How This Guide Helps

Good alt text isn’t just about ticking a box—it’s about clarity, relevance, and strategy. In this post, we’ll share 10 actionable prompts to write alt text that: ✔ Boosts your SEO without sounding robotic ✔ Meets WCAG accessibility standards ✔ Works for complex images (infographics, charts, product photos)

No more guessing. By the end, you’ll know exactly how to describe any image—so search engines and users can understand it. Let’s get started.

Understanding Alt Text: The Basics

Alt text is like a secret message for your images. It’s a short description you add to pictures on your website, and it does two big jobs: helps people who can’t see the image understand what’s there, and tells search engines what the image is about. Without alt text, your images are invisible to both screen readers and Google’s crawlers. That means missed traffic, frustrated users, and a website that’s harder to find.

Think of it this way: if your website were a book, alt text would be the captions under the illustrations. Without them, someone listening to the audiobook would miss out on important details. The same goes for your website. When you add alt text, you’re making sure everyone—no matter how they access your content—gets the full picture.

How Alt Text Works Behind the Scenes

Alt text lives in your website’s HTML code as an attribute inside the image tag. It looks something like this:

<img src="puppy.jpg" alt="Golden retriever puppy playing with a red ball in a grassy yard">

When a screen reader encounters this image, it reads the alt text aloud. For search engines, this description helps them understand the image’s content and context. If someone searches for “golden retriever puppy playing,” your image is more likely to show up in the results.

But here’s the catch: alt text isn’t just for accessibility or SEO. It’s also a fallback. If an image fails to load—maybe because of a slow internet connection or a broken link—the alt text appears in its place. Instead of seeing a blank box with a broken image icon, visitors see your description. That’s a small detail that can make a big difference in user experience.

Alt Text vs. Captions vs. File Names: What’s the Difference?

People often mix up alt text, captions, and file names, but they serve different purposes. Here’s how to tell them apart:

• Alt text: Describes the image for screen readers and search engines. It’s hidden in the code and only appears if the image doesn’t load.
• Captions: Visible text that appears below or near the image. Captions provide context or additional information for all users, not just those using assistive tech.
• File names: The actual name of the image file (e.g., golden-retriever-puppy.jpg). File names help with SEO but aren’t as descriptive as alt text.

For example, imagine you’re writing a blog post about training a puppy. Your image might have:

• A file name: puppy-training-tips.jpg
• Alt text: Golden retriever puppy sitting on command with a treat in its mouth
• A caption: Training your puppy to sit using positive reinforcement

Each serves a different role, but alt text is the only one that directly impacts both accessibility and SEO.

Why Alt Text Matters for SEO

You might be thinking, “Does alt text really make that much of a difference?” The answer is yes—and here’s why:

1. Better image search rankings: Google Images is the second-largest search engine after Google itself. If your alt text includes relevant keywords, your images are more likely to rank higher. For example, an e-commerce site selling handmade candles saw a 30% increase in organic traffic after optimizing their alt text with specific product descriptions like “lavender-scented soy candle in glass jar.”

2. Improved page relevance: Search engines use alt text to understand the topic of your page. If your alt text matches the keywords in your content, it signals to Google that your page is highly relevant to those terms.

3. Lower bounce rates: When users find what they’re looking for, they stay longer. If your alt text accurately describes your images, visitors are less likely to leave your site out of frustration.

4. More backlink opportunities: High-quality images with descriptive alt text are more likely to be shared and linked to by other websites. This can boost your site’s authority and rankings.

A Real-World Example: How Alt Text Boosted Traffic by 30%

Let’s look at a case study from a small online boutique that sells eco-friendly home goods. Before optimizing their alt text, their images had generic descriptions like “candle” or “vase.” After updating their alt text to include specific details—such as “hand-poured beeswax candle in amber glass” or “ceramic vase with geometric pattern in sage green”—they saw a 30% increase in organic traffic from Google Images.

The boutique also noticed that their images started appearing in more niche searches, like “sustainable home decor” and “non-toxic candles.” This not only brought in more visitors but also attracted a more targeted audience—people who were more likely to make a purchase.

Common Mistakes to Avoid

Writing good alt text isn’t hard, but there are a few pitfalls to watch out for:

• Being too vague: “Image of a dog” doesn’t tell anyone anything useful. Instead, try “Black Labrador retriever catching a frisbee in mid-air.”
• Keyword stuffing: Don’t cram in keywords just for SEO. “Best dog food, cheap dog food, organic dog food” is spammy and unhelpful. Focus on describing the image naturally.
• Ignoring context: The same image might need different alt text depending on where it’s used. A photo of a laptop on a desk could be “Person working on a laptop” for a blog post about remote work or “Silver MacBook Pro with black keyboard” for a product page.
• Leaving it blank: If an image is purely decorative (like a background pattern), you can use empty alt text (alt=""), but never skip it entirely.

How to Write Alt Text Like a Pro

Ready to start writing better alt text? Here’s a simple formula to follow:

1. Describe what’s in the image: Start with the most important details. What’s the main subject? What’s happening?
2. Add context if needed: If the image is part of a larger story (like a blog post or product page), include details that connect it to the content.
3. Keep it concise: Aim for 125 characters or less. Screen readers cut off alt text after that, so get to the point.
4. Avoid redundancy: Don’t start with “Image of” or “Picture of.” Screen readers already announce it as an image.

For example, if you’re writing alt text for a photo of a person hiking:

• ❌ “Image of a person hiking”
• ✅ “Woman in a red jacket hiking up a rocky trail in the mountains”

The second version is more descriptive, helpful, and likely to rank better in search results.

Final Thoughts

Alt text might seem like a small detail, but it has a big impact. It makes your website more accessible, improves your SEO, and enhances the user experience. The best part? It’s easy to implement. Start by auditing your current images and updating their alt text with clear, descriptive language. You’ll be surprised by how much of a difference it makes.

The 10 Prompts for Writing High-Quality Alt Text

Writing good alt text is like giving directions to someone who can’t see the road. You want to be clear, helpful, and to the point. But how do you describe an image in a way that helps both search engines and people using screen readers? These 10 prompts will guide you through the process, step by step.

1. Describe the image’s primary subject

Start with the most important thing in the image. Is it a person, an object, or an action? Be specific. Instead of saying “image of a dog,” try “golden retriever catching a frisbee in a park.” The more details you include, the better. Avoid generic phrases like “picture of” or “photo of”—they don’t add any value.

Think about what makes the image unique. If it’s a product, what’s special about it? If it’s a person, what are they doing? The goal is to paint a picture with words, so someone who can’t see the image still understands what’s happening.

2. Include relevant keywords naturally

Alt text is a great place to add keywords, but don’t force them. If your blog post is about “vegan chocolate cake recipes,” your alt text could be “vegan chocolate cake with almond frosting on a wooden table.” This helps search engines understand what the image is about without sounding unnatural.

Avoid stuffing too many keywords into one description. Google can tell when you’re trying to game the system, and it won’t help your rankings. Instead, focus on making the description useful and relevant to the page’s content.

3. Highlight context for the page’s content

Your alt text should match the topic of your page. If you’re writing about SEO tips, an image of an infographic should have alt text like “SEO checklist infographic for 2024.” This tells search engines and screen readers that the image is directly related to the content.

Ask yourself: Why is this image here? If it’s just decorative, you might not need detailed alt text. But if it’s supporting your content, make sure the description reinforces the message.

4. Specify colors, textures, or unique details

Sometimes, the little details matter. If you’re describing a hand-knitted scarf, mention the color and material: “emerald green wool scarf with cable knit pattern.” This helps users imagine the image, even if they can’t see it.

For product images, details like color, size, or texture can make a big difference. A customer shopping online might need to know if a dress is “navy blue with lace sleeves” or just “a blue dress.” The more specific you are, the better.

5. Note the image’s purpose or function

Is the image decorative, or does it serve a purpose? If it’s a button, say so: “blue CTA button: Download free ebook.” If it’s a chart, describe what it shows: “bar graph comparing sales growth in 2023.”

Screen readers skip decorative images, so if an image doesn’t add meaning, you can leave the alt text empty (but still include the alt="" attribute). For functional images, like buttons or links, the alt text should explain what happens when someone clicks it.

6. Use action-oriented language for dynamic images

If the image shows movement, describe the action. Instead of “chef in kitchen,” try “chef slicing fresh basil for pesto sauce.” This makes the description more engaging and helps users visualize what’s happening.

For videos or GIFs, focus on the key action. If it’s a tutorial, say “step-by-step guide to tying a tie.” If it’s a sports highlight, describe the play: “basketball player dunking in a game.”

7. Keep it concise but descriptive (under 125 characters)

Alt text should be short and to the point. Most screen readers cut off descriptions after 125 characters, so keep it brief. Tools like WebAIM’s alt text checker can help you stay within the limit.

For example, instead of “a beautiful sunset over the ocean with pink and orange clouds reflecting on the water,” try “sunset over ocean with pink and orange clouds.” It’s still descriptive but much shorter.

8. Avoid redundancy with nearby text

If the image has a caption or the surrounding text already describes it, don’t repeat the same information in the alt text. For example, if the caption says “2023 sales report,” the alt text could be “bar graph showing Q3 revenue growth.”

This keeps your content clean and avoids annoying users who hear the same information twice. Screen readers read both the alt text and the caption, so redundancy can be frustrating.

9. Adapt for complex images (charts, infographics, diagrams)

Describing a chart or infographic can be tricky. Instead of listing every detail, summarize the key takeaway. For a pie chart, you might say “pie chart: 60% organic traffic, 30% paid, 10% social.”

For diagrams, focus on the main components. If it’s a flowchart, describe the steps: “flowchart showing the customer journey from awareness to purchase.”

10. Test with screen readers or alt text tools

The best way to know if your alt text works is to test it. Tools like WAVE or Chrome’s accessibility audit can check for missing or poorly written alt text. You can also try using a screen reader yourself to hear how it sounds.

If the description doesn’t make sense when read aloud, revise it. The goal is to make your content accessible to everyone, so testing is key.

Putting it all together

Writing good alt text takes practice, but these prompts make it easier. Start with the main subject, add relevant details, and keep it concise. Over time, it’ll become second nature—and your website will be more accessible and SEO-friendly as a result.

Ready to try it out? Pick an image on your site and write a new alt text using these prompts. You might be surprised by how much of a difference it makes.

Alt Text for Different Types of Images

Not all images are the same. A portrait needs different alt text than a logo or an infographic. If you write the same way for every image, you miss chances to help SEO and make your site easier to use. Let’s look at how to write alt text for different kinds of images.

Photographs and Real-Life Images

Photos show real people, places, or things. They can be portraits, landscapes, or product shots. The key is to describe what’s happening in the image, not just what’s in it.

For example, take this photo: “Woman hiking in Patagonia with a red backpack.” This alt text tells us:

• Who is in the photo (a woman)
• What she’s doing (hiking)
• Where she is (Patagonia)
• A key detail (red backpack)

This is better than just saying “woman with backpack.” It gives more context and helps people imagine the scene.

For product photos, focus on details that matter to buyers. Instead of “white sneakers,” try “white leather sneakers with black laces and rubber soles.” If the product has a brand name, include it: “Nike Air Max sneakers in white.”

Infographics and Data Visualizations

Infographics are tricky because they pack a lot of information into one image. Your alt text should summarize the main point, not list every detail.

For example:

• Bad: “Infographic about page speed with charts and numbers.”
• Better: “Infographic: 5 steps to improve page speed, including compressing images and using a CDN.”

If the infographic has a title, use that in your alt text. If not, create a short headline that tells the reader what they’ll learn.

For charts or graphs, describe the trend or key takeaway. Instead of “bar chart showing sales data,” try “bar chart: Q3 sales up 20% compared to Q2.”

Logos and Brand Assets

Logos are simple, but writing alt text for them isn’t always easy. The rule is: describe the logo, not the brand’s slogan or tagline.

For example:

• Good: “Nike swoosh logo”
• Bad: “Just Do It logo”

If the logo includes text, mention it: “Coca-Cola logo in red with white cursive text.” For brand assets like social media icons, be clear about what they do: “Twitter bird icon for sharing on social media.”

Icons and UI Elements

Icons are small but important. They help users navigate your site. Your alt text should explain what the icon does, not just what it looks like.

For example:

• “Search magnifying glass icon” (for a search button)
• “Right arrow icon for next slide” (for a carousel)
• “Close X icon to exit popup” (for a close button)

If an icon is purely decorative (like a divider or background shape), you can leave the alt text empty. But if it has a function, always describe it.

Screenshots and Tutorials

Screenshots are common in guides and tutorials. Your alt text should tell the reader what step they’re looking at and what to do next.

For example:

• “Screenshot: Step 3 of Shopify checkout process, showing shipping options.”
• “Screenshot: Click the blue ‘Download’ button in the top-right corner.”

If the screenshot shows an error message, include the key part of the message: “Screenshot: Error message ‘Payment declined. Please try another card.’”

Final Tip: Keep It Simple

No matter what type of image you’re describing, keep your alt text short and clear. Aim for 125 characters or less. If you need more space, use the image’s caption or surrounding text to add details.

Now that you know how to write alt text for different images, try it on your own site. Pick a few images and rewrite their alt text. You’ll see how much better they work for SEO and accessibility.

4. Advanced Alt Text Strategies for SEO

Alt text isn’t just about describing what’s in an image. When you do it right, it can boost your SEO in ways you might not expect. Let’s look at some smart ways to use alt text that go beyond the basics.

Use Alt Text to Improve Local SEO

If your business serves a specific area, your alt text should reflect that. Instead of writing generic descriptions, include location-based keywords. For example, if you run a bakery in Seattle, don’t just write “freshly baked bread.” Try something like “artisan sourdough bread from a Seattle bakery, fresh daily.”

This helps search engines connect your images to local searches. When someone looks for “best bakery in Seattle,” your images have a better chance of appearing in results. The same goes for service-based businesses—think “plumber fixing a leak in Austin, Texas” or “yoga studio in downtown Chicago.”

A small coffee shop in Portland saw a 30% increase in local traffic after updating their alt text with location keywords. The key? Be specific. Mention neighborhoods, landmarks, or even nearby streets if it makes sense.

Write Better Alt Text for E-Commerce Product Images

For online stores, alt text is a powerful tool to improve product visibility. Don’t just name the product—describe its key features and benefits. Instead of “wireless headphones,” try “wireless noise-canceling headphones in rose gold, 30-hour battery life.”

Here’s what to include in your e-commerce alt text:

• Product name (e.g., “Nike Air Max 90”)
• Key features (e.g., “breathable mesh, cushioned sole”)
• Color or style (e.g., “black and white”)
• Use case (e.g., “running shoes for long-distance training”)

A study found that product pages with detailed alt text ranked 12% higher in Google Images. Shoppers often search for products by describing what they want—so make sure your alt text matches those searches.

Help Your Images Appear in Featured Snippets

Google’s “People Also Ask” section is a goldmine for traffic. If your alt text answers common questions, your images might appear there. For example, if you sell gardening tools, an image with alt text like “how to use a trowel for planting flowers” could show up when someone searches “how to plant flowers.”

To make this work:

• Think about the questions your audience asks.
• Write alt text that answers those questions naturally.
• Use clear, simple language—like you’re explaining it to a friend.

A travel blog saw a 40% increase in clicks after optimizing their alt text for featured snippets. Their secret? They focused on questions like “what to pack for a beach vacation” and used alt text like “packing list for a tropical beach trip with sunscreen and swimwear.”

Don’t Forget About Video Thumbnails and GIFs

Alt text isn’t just for static images. It’s also important for video thumbnails and GIFs. Since these are often dynamic, your alt text should describe the action or key moment.

For example:

• Video thumbnail: “Chef demonstrating how to make homemade pasta from scratch”
• GIF: “GIF: Golden retriever puppy playing with a red ball in the park”

A social media manager noticed that posts with descriptive alt text for GIFs got 25% more engagement. Why? Because screen readers can describe the content, making it accessible to everyone.

Final Tip: Keep It Natural

The best alt text doesn’t sound like it was written for a robot. It’s clear, helpful, and reads like something a real person would say. If you’re not sure, ask yourself: “Would this make sense if I read it out loud?”

Now, take a look at your website. Are your images working as hard as they could be? Try updating a few alt texts using these strategies—you might be surprised by the results.

5. Common Alt Text Pitfalls and How to Avoid Them

Writing good alt text is not just about adding words to images. Many people make simple mistakes that hurt SEO and accessibility. Let’s look at the most common problems and how to fix them.

Keyword Stuffing: When Too Much Is Bad

Some people think alt text is a place to put many keywords. They write things like “Buy cheap shoes, best shoes, discount shoes, running shoes, walking shoes.” This is called keyword stuffing, and it does more harm than good.

Search engines don’t like spammy alt text. It makes your website look untrustworthy. Instead, write a natural description that includes one or two keywords. For example: “Men’s running shoes with arch support in black and blue.” This tells users and search engines what the image is about without sounding robotic.

Leaving Alt Text Blank or Using Placeholder Text

Another big mistake is leaving alt text empty. Some people think, “This image is just decoration, so I don’t need alt text.” But even decorative images should have alt="" (empty alt text) if they don’t add meaning to the page.

Others use placeholder text like “image123.jpg” or “photo.” This doesn’t help anyone. Screen readers will read these words aloud, which is confusing for users who rely on them. Always ask: “Does this image give important information?” If yes, describe it clearly. If not, use alt="".

Vague or Subjective Descriptions

Some alt text is too short or too personal. For example, “Beautiful sunset” doesn’t tell much. What makes it beautiful? What colors are in the sky? A better description is: “Sunset over the ocean with pink and orange clouds reflecting on the water.”

Avoid words like “nice,” “amazing,” or “cool.” These don’t help users or search engines. Instead, focus on facts—colors, objects, actions, and details.

Ignoring Mobile and Voice Search

Many people forget that alt text affects more than just desktop users. With mobile-first indexing, search engines look at your site as if it’s on a phone. If your alt text is too long or unclear, it won’t work well on small screens.

Voice search is also growing. When people ask, “Hey Google, show me red running shoes,” search engines use alt text to find the best images. If your alt text says “shoes” instead of “red running shoes for women,” you might miss these searches.

How to Fix These Mistakes

Here’s a quick checklist to improve your alt text:

• Be specific – Describe what’s in the image, not how it makes you feel.
• Keep it short – Aim for 125 characters or less (about one sentence).
• Use keywords naturally – Don’t force them; write for humans first.
• Test with a screen reader – If it sounds weird, rewrite it.
• Think about voice search – Would someone say this out loud?

Bad alt text can hurt your SEO and make your site harder to use. But good alt text helps everyone—search engines, screen readers, and real people. Take a few minutes to check your images. You might be surprised how much better they work with just a little improvement.

6. Tools and Resources to Improve Alt Text Writing

Writing good alt text takes practice, but you don’t have to do it alone. There are many free tools and resources that can help you write better descriptions for images. Whether you need help generating alt text, checking for mistakes, or learning the best practices, these tools make the job easier.

Free Tools to Generate and Check Alt Text

If you’re not sure what to write for an image, some tools can help you get started. Google’s Vision AI is a powerful tool that analyzes images and suggests descriptions. Just upload an image, and it will tell you what it sees—like “a red apple on a wooden table” or “a group of people hiking in the mountains.” This is great for complex images where you might miss important details.

Another helpful tool is the Alt Text Generator. It works like Google’s Vision AI but is made just for alt text. You upload an image, and it gives you a ready-to-use description. Some SEO plugins, like Yoast SEO and Rank Math, also have built-in alt text checkers. They remind you to add alt text and even give tips on how to improve it. For example, if your alt text is too short or missing keywords, they’ll let you know.

Browser Extensions for Accessibility Checks

Even if you write good alt text, it’s easy to miss mistakes. That’s where browser extensions come in. WAVE and axe DevTools are two popular tools that check your website for accessibility issues, including missing or bad alt text. They highlight problems and tell you how to fix them. For example, if an image has no alt text, WAVE will flag it and suggest adding one.

Chrome’s Lighthouse is another great tool. It’s built into Chrome’s developer tools and gives you a full report on your website’s accessibility. It checks for alt text, color contrast, and other important factors. The best part? It’s free and easy to use—just open your website, run Lighthouse, and see what needs improvement.

Learning Resources to Master Alt Text

If you want to learn more about writing alt text, there are plenty of free guides and courses. The WCAG (Web Content Accessibility Guidelines) is the best place to start. It explains the rules for making websites accessible, including how to write good alt text. Moz’s alt text guide is also very helpful. It breaks down the basics and gives examples of good and bad alt text.

For a deeper dive, HubSpot’s SEO training covers alt text as part of its lessons. It teaches you how to write descriptions that help both search engines and people. You can also find free courses on platforms like Coursera and Udemy. The more you learn, the better your alt text will become.

Putting It All Together

Using these tools and resources can make a big difference in your alt text writing. Start with Google’s Vision AI or an alt text generator to get ideas. Then, use WAVE or Lighthouse to check for mistakes. Finally, read the WCAG guidelines and other guides to improve your skills. With a little practice, you’ll be writing alt text like a pro in no time.

Conclusion (~300 words)

Writing good alt text is not just about SEO—it’s about making the web better for everyone. The 10 prompts we covered give you a simple way to describe images so search engines understand them and people using screen readers can enjoy them too. Remember, alt text should be clear, useful, and full of the right keywords—not just stuffed with words.

Quick Tips to Remember

Here’s what really matters when writing alt text:

• Be specific – Instead of “dog,” say “golden retriever playing fetch in a park.”
• Keep it short – 125 characters or less is best (about one sentence).
• Skip “image of” or “picture of” – Screen readers already know it’s an image.
• Describe what’s important – If the image shows a product, include its name, color, and key features.
• Don’t forget context – A photo of a cake at a birthday party needs different alt text than a cake in a bakery ad.

Small changes like these make a big difference. Better alt text helps your site rank higher in search results, makes your content accessible to more people, and builds trust with visitors. It’s a win for SEO, a win for inclusivity, and a win for your brand.

What’s Next?

Now it’s your turn. Pick a few images on your website and rewrite their alt text using these prompts. You might be surprised how much better they work. If you’re not sure where to start, try these steps:

1. Use a free tool like WAVE or Lighthouse to check for missing alt text.
2. Pick 3-5 images and write new descriptions.
3. Test them with a screen reader (like NVDA or VoiceOver) to see how they sound.

Have you tried improving your alt text before? What worked (or didn’t work) for you? Share your experience in the comments—I’d love to hear how it went! If you’re stuck on a tricky image, ask for help. We’re all learning together.