AI Alt Text Generator: Write Better Image Alt Text (2026)

An AI alt text generator turns a short description of an image into ready-to-paste alt text. That is a short line that tells screen reader users what the image shows and tells search engines what it is about. Good alt text describes what the image does on that page, in plain words, in under about 125 characters, with at most one keyword placed naturally. Decorative images get an empty alt attribute instead. A generator gives you phrasing options fast, but you still decide what each image is for, check that the output is accurate, and leave decorative images silent.

Disclosure: LaunchIt runs a free AI Alt Text Generator, and LaunchIt is a launch platform that gives every listing a dofollow link. We have an interest in both, so weigh what follows accordingly.

Why this post exists: Search Console shows that people who search phrases like "image alt text generator" find our tool page from deep positions and almost never click through. This guide is meant to sit beside the tool.

Most founders skip alt text, paste the filename, or stuff keywords into every image. All three hurt accessibility and waste Google Images traffic.

What alt text is and why it matters

Alt text is a short text alternative stored in the alt attribute of an image. It is not visible on the page. Screen readers speak it aloud, browsers show it when an image fails to load, and search engines read it to understand what the image contains.

Accessibility comes first

Someone using a screen reader hears your page rather than seeing it. When they reach a product screenshot with no alt text, they get nothing useful, or a filename like IMG_4021.png read aloud. When they reach a linked logo or icon with no alt, they cannot tell where the link goes. That is the real cost: a person cannot use part of your page.

So we prioritise accessibility over rankings. Alt text written for a listener usually works for search too. Alt text written for search first tends to become a keyword list nobody can use.

Search is the second reason

Search engines cannot see an image the way a person does. Alt text, along with the filename and the text around the image, is one of the clearest signals of what the image shows. It matters even more in Google Images, which drives a lot of visits for products people search for by look: dashboards, templates, design tools, physical goods. On a linked image, alt text also acts as anchor text.

Good alt text vs bad alt text

Here is what those three habits look like. You will probably recognise at least one from your own site.

• Skipped. No alt attribute at all. Screen readers may fall back to the filename, and search engines get no description.
• The filename. Alt text such as "hero-final-v3", usually because someone or a plugin copied the upload name into the alt field.
• Keyword stuffing. The same phrase, or a list of phrases, on every image, decorative ones included. Our tool page calls keyword-stuffed alt on decorative images a spam signal, and it is miserable to listen to.

Before and after examples

These examples are only illustrations. They are for a made-up project management app we will call Planbird, not a real site, and we wrote every alt string for this post.

• Hero screenshot. Before: "screenshot". After: "Kanban board in dark mode with tasks grouped into To do, In progress and Done". The after says what is on screen and uses the keyword because the keyword describes what is really there.
• Filename as alt. Before: "IMG_4021". After: "Weekly report showing tasks completed by each team member".
• Keyword stuffed. Before: "project management software, best project management tool, free project management app". After: "Project management dashboard with overdue tasks highlighted in red". One keyword, where a person would say it.
• Padded. Before: "Image of a picture of a chart". After: "Burndown chart showing remaining work falling steadily across the sprint". Screen readers already announce an image, so "image of" wastes the listener's time.
• Image used as a button. Before: "green arrow button". After: "Start your free trial". Describe what it does, not what it looks like.

Same image, different page

The same screenshot needs different alt text on a features page than in a tutorial. On the features page: "Kanban board in dark mode with drag and drop task cards". In a tutorial on moving tasks: "Dragging a task card from In progress to Done on the Kanban board". Both are accurate, and each fits what the reader needs at that point. So use a different variant for each context rather than one string everywhere.

The rules that hold up

• Describe function, not just appearance. Ask what the image is doing on this page.
• Skip "image of" and "picture of". Start with the subject.
• Stay under about 125 characters. Screen readers may cut off longer descriptions. Put extra detail, such as what a complex chart means, in the visible page text.
• One keyword, naturally placed. If it does not fit the sentence, leave it out.
• Pair it with a descriptive filename. A file named kanban-board-dark-mode.png reinforces "Kanban board in dark mode". IMG_4021.png reinforces nothing.

When to use empty alt

Some images are pure decoration: background textures, dividers, flourishes, or an icon beside a label that already says the same thing. Describing them adds noise. For these, set the alt attribute to an empty string.

Empty alt is not the same as missing alt. An empty alt tells screen readers to skip the image. A missing one leaves them guessing, and many read out the filename instead. Keep the attribute and leave it blank.

A simple test: if you removed the image, would anyone lose information or a way to act? If not, it is decorative.

• Decorative icons: empty alt. A small tick beside the words "Unlimited projects" adds nothing for a listener.
• Icons used alone as buttons: not decorative. A magnifying glass that opens search needs alt text such as "Search".
• Logos: the company name, so Planbird's logo gets "Planbird". A row of customer logos carries information too, so each one gets that customer's name.

How to use an AI alt text generator without blindly pasting

An alt text generator handles the tedious part: turning what you see into a short sentence, several ways, with a keyword worked in naturally. It cannot decide what the image is for. That part is yours.

Our free image alt text generator works from your description rather than the image file, and needs no account. So the judgement step comes first: you decide what matters, and it handles the phrasing.

1. Describe the image in your own words. Cover the objects, actions and context, plus the page topic so the keyword fits naturally. "Features page screenshot, Kanban board, dark mode, card being dragged" is plenty.
2. Pick from five variants. Each stays under 125 characters. Some are more literal, some more contextual and some more keyword-forward. Choose the one that suits this page.
3. Edit, then paste. Fix anything not true of the image, then paste it into the alt attribute or the alt text field in your CMS media library.

What to check before you paste

• Accuracy. AI tools can add details you never gave them. Read each variant against the image and delete anything not on screen.
• Purpose. Does it say what the image does here, or only what it looks like?
• Keyword fit. If the keyword-forward variant sounds like an advert, pick a plainer one.
• Duplication. Different images on one page should not share an alt string.
• Decoration. No generator should talk you into describing a divider.

Tools that read the image file directly can write first drafts for lots of images at once, but they see appearance, not purpose. They do not know the screenshot is there to show off a feature, or that the icon is decorative. Review the output either way.

How to audit a page for missing alt text

Start by running the page through our free SEO Checker. It audits any public URL against 18 weighted on-page checks, image alt text included, with no account needed, and shows Domain Rating separately.

One caveat: the SEO Checker reads the HTML your server sends and does not run JavaScript. So images added by JavaScript in the browser can show as missing even though visitors see them. That is either a false alarm or a hint that crawlers which skip JavaScript may miss those images too. If you want the fixes written for you, the Website Audit adds paste-ready fix code, a Google preview and directory listings.

What to look for

• Missing alt on images that carry information.
• Filenames used as alt text.
• Alt text that opens with "image of" or "picture of".
• Keyword-stuffed alt on decorative images.
• Linked images with no alt, which leave the link without a name.

Two quick manual checks

• Listen to the page. Turn on your operating system's built-in screen reader and move through the page. You will hear filenames and unnamed links you never noticed.
• Check your CMS media library. Images uploaded in a rush before launch are often the ones with blank alt fields.

Alt text is one line on a longer list. Our SEO checklist for 2026 covers the other on-page basics.

A short alt text workflow for your product page

Run this on your product page before a launch. You can do it in one sitting.

1. Run the SEO Checker. Note every image it flags.
2. Label every image. Informative, functional (a link or button) or decorative.
3. Clear the decorative ones. Set the alt attribute to an empty string and remove any stuffed alt your theme added.
4. Name the logos. Company name as the alt text.
5. Describe functional images by what they do. "Start your free trial", "Search", "Watch the demo".
6. Generate and edit the rest. Describe each informative image, mention the page topic, pick the variant that fits and fix anything inaccurate. Not sure which phrase the page should target? Start with the Keyword Ideas Generator.
7. Rename new uploads. Use descriptive, hyphenated filenames such as kanban-board-dark-mode.png.
8. Re-run the check. Confirm the warnings are gone. Images added by JavaScript may still show as missing.
9. Fix the neighbours while you are there. Tighten the title with the Title Tag Generator, write a meta description with the Meta Description Generator, and set your share preview with the Open Graph Generator.

If you are preparing a launch, this fits into our product launch checklist.

Frequently asked questions

What is an AI alt text generator?

An AI alt text generator is a tool that helps you generate alt text for images. Some read the image directly. Ours takes a plain-language description from you and returns five alt text variations per image, each under 125 characters, with a keyword worked in naturally. It speeds up the writing, but you still check that each line is accurate and fits the image's purpose.

How does alt text affect SEO?

Alt text helps search engines understand what an image shows and how it relates to the page. On a linked image, it works like anchor text. It is one signal among many. Good alt text will not rescue a weak page, but missing or stuffed alt throws away an easy win. For the wider picture, see our guide on how to do SEO in 2026.

How long should alt text be?

Aim for under about 125 characters. Screen readers may cut off longer descriptions, and a short sentence is easier to listen to. If an image needs more explanation, put it in the visible text nearby and keep the alt text as a summary.

Should decorative images have alt text?

They should have empty alt text, not a description. Give backgrounds, dividers, flourishes and decorative icons an alt attribute set to an empty string, so screen readers skip them. Keyword-stuffed alt on decorative images is a spam signal.

Is missing alt text a legal risk?

It can be, under rules such as the Americans with Disabilities Act and the European Accessibility Act. Images without text alternatives are among the most frequently cited accessibility failures. We are not lawyers, so ask one if you have a specific concern. Adding proper alt text is still one of the simplest accessibility fixes you can make.

What is the difference between alt text and a caption?

Alt text sits in the HTML for screen readers and search engines and is not visible. A caption is visible text below the image that everyone reads. The title attribute is different again. It is a hover tooltip that most screen readers skip and that carries no SEO value, so it is no substitute for alt text.

Does alt text help images rank in Google Images?

Yes. Alt text is one of the ways Google understands an image, along with the filename and the text around it on the page. Descriptive alt text and filenames on a relevant page give an image a fair chance. They will not make a poor image rank on their own.

Takeaways, and a launch while you are here

• Write for the listener first. It usually helps search too.
• Describe purpose, not pixels. Vary alt text by context.
• Silence decorative images properly. Empty alt, never missing or stuffed.
• Use a generator for phrasing, not judgement. Check every variant before you paste.
• Audit before you launch. Check again after new uploads.

Alt text is one small part of a page that ranks. Links are another, and they are harder to earn. If your product is ready, you can launch it on LaunchIt. Every listing is a permanent page with a dofollow link to your site, and our pricing page shows LaunchIt's live Ahrefs Domain Rating as 71.

Basic Launch is free. It waits in the standard review queue, where the earliest free slot is currently about two months out. It needs a link to LaunchIt from your site before approval, and the listing page never expires. Premium Launch is $24.99 one-time, with no subscription. You can launch as soon as tomorrow on any open day and sit on the homepage all day on launch day. You also get a verified badge, a highlighted card, a newsletter feature to 1,900+ subscribers and a DirPilot submission, with no badge needed on your site. Our pricing page reports that premium listings get 2.3x more clicks than free ones, from live data. The Boost bundle is Premium plus 30 days featured, for $49 one-time.

To be straight with you: we run LaunchIt, so of course we would say this. One link will not transform your Domain Rating or your rankings. It is a real dofollow referring domain from a DR 71 site, and it works best as one part of a steady approach to backlinks for startups. Fix your alt text, launch, and keep going.