AI Alt Text Generator
Explain what the image communicates in its page context—not merely what objects it contains. Describe the image and choose whether it informs, performs an action or is decorative. This tool works from your description. Try the same tool available in your dashboard, then carry your input, options and result into your account.
Explain what the image communicates in its page context—not merely what objects it contains.
Add at least 3 words to describe the image.
The result stays concise, avoids “image of,” and respects the image’s purpose.
Five rules, all of them consequences of one fact.
The fact is that a person is hearing this. Everything below follows from imagining that clearly.
- Somebody is listening to thisThe single fact that decides everything else. Alt text is read aloud by a screen reader, in sequence, as part of a sentence somebody is following. Every rule below follows from imagining that. Keyword-stuffed alt text is not a neutral SEO tactic; it is a string of search terms spoken into somebody's ear where a description should have been.
- Describe why the image is there, not everything in itThe same photograph needs different alt text on different pages. On a recipe page, a hand testing dough for elasticity. On a page about kitchen lighting, the same shot might need a description of the light. Ask what the image is doing here, then describe that.
- Decorative images take empty alt text, not a descriptionThe rule most guides omit and the one that does the most damage when broken. A background flourish or divider carrying no information should have alt="" so the screen reader skips it. Describing it interrupts the page with noise. Missing the attribute entirely is worse still, because some readers then announce the filename.
- Concise, with enough detailThere is no universal 125-character limit. Keep the alternative concise while including the information or function the image contributes. If an image genuinely needs more, it needs a caption or a description in the page body, where everyone can read it.
- No “image of” or “picture of”The screen reader has already announced that it is an image. Adding it spends characters repeating what the listener was just told, which is exactly the kind of small friction that accumulates across a page with thirty images on it.
The same image needs different alt text on different pages.
This is the part no tool can do for you, and it is the difference between alt text that works and alt text that technically exists.
Take one photograph: a person kneading dough on a wooden counter, in strong side light. On a recipe page, what matters is the technique — the heel of the hand pushing through the dough, whether it looks slack or firm. On a page about kitchen renovation, what matters is the counter. On a page about a bakery, it might be the person. Same file, three correct and entirely different descriptions.
So the question is never what is in this image. It is what would a listener lose if this image were not here. Answer that in a sentence and you have the alt text.
Which is why generated alt text is a draft. An assistant looking at the file can tell you what is in it accurately, and it has no idea what the surrounding page is arguing. Its output is an inventory to cut down against your own context, not a finished attribute.
And if the image conveys nothing, say so with silence. A divider, a background texture, a decorative icon next to a heading that already says the word. Empty alt attribute, screen reader moves on. Describing it is worse than leaving it out.
Charts, images of text, and images that are links.
Three categories break the usual advice, and all three are common enough to be worth knowing.
Charts and infographics. The information is the point, so “bar chart showing quarterly sales” conveys nothing at all — it describes the container and withholds the contents. Either put the finding in the alt text (“sales fell 12% in Q3, the first decline in two years”) or, better, put the underlying figures in the page as a table. A table is accessible, searchable, and useful to sighted readers too.
Images of text. These should mostly not exist: they are unsearchable, they break when scaled, and they are invisible to anyone using a screen reader. Where one is unavoidable — a logo with a wordmark, a screenshot of an error message — the alt text has to carry the words exactly, not summarise them.
Images used as links or buttons. The alt text becomes the link text, so it must describe the destination rather than the picture. An icon linking to your basket takes “basket” or “view basket”, not “shopping trolley icon”. Getting this wrong leaves somebody navigating by links with a list of picture descriptions and no idea where any of them go.
Alt text from ChatGPT, Claude, Gemini, DeepSeek, Grok, LLaMA and Perplexity.
They differ more on this task than on most, because describing an image and knowing why it is on a page are different capabilities.
ChatGPT alt text generator
Describes images well and describes too much of them.
Given an image ChatGPT produces an accurate, thorough description — and thorough is the failure mode here. It inventories the scene rather than identifying what matters, so you get forty words about a photograph where twelve would have carried the information the page needed.
It also cannot know why the image is on your page, which is the thing that decides what to describe. Its output is a good starting inventory to cut down, not a finished attribute.
Claude alt text generator
The most useful descriptions, and the most likely to run long.
Claude is noticeably better at identifying what an image conveys rather than what it contains, which is the harder and more valuable half of the job. Its descriptions read as though written by somebody thinking about a listener.
The trade is length. It tends toward a sentence and a half where one would do, so the edit is usually cutting rather than rewriting.
Gemini alt text generator
Fast and literal, which suits some images and not others.
Its descriptions are concise and inventory-like, which works well for product photography and diagrams where the content is the point. It works less well for images doing something atmospheric or illustrative, where the literal description misses the reason the image is there.
For a catalogue of product shots it is probably the most efficient of the assistants. For editorial imagery, check what it returned against why you chose the picture.
DeepSeek alt text generator
Best on technical images, and technical about everything else.
For diagrams, charts and schematics its precision is genuinely useful, because those images have content that has to be conveyed accurately rather than impressionistically. A chart described vaguely is a chart that is inaccessible.
For photographs it applies the same register, producing descriptions that read as specifications. Worth using selectively rather than across a whole library.
Grok alt text generator
Personality is the wrong register for this attribute.
Alt text is a functional description delivered into somebody's ear as part of a sequence. Wit in it is friction, because the listener is trying to follow a page rather than be entertained by one attribute of it.
This is the one writing task on this site where Grok's usual advantage is a liability, and the edit is to flatten the voice out entirely.
LLaMA alt text generator
Varies with the deployment, and the vision capability varies most.
LLaMA is weights rather than a product, and image handling differs sharply between deployments. Some produce competent descriptions and some produce confident descriptions of things that are not in the image, which is a worse failure here than elsewhere because nobody sighted will notice.
Check what it returns against the actual image. An inaccurate description is worse than no description, because a listener has no way to know it is wrong.
Perplexity alt text generator
Not really the tool for this, and worth knowing why.
It is built to answer with sources, and alt text is a description of a specific file in front of you rather than a question with an answer elsewhere. Its output tends to describe the subject in general rather than this particular image.
Where it is genuinely useful is naming what is in a technical or historical image — identifying a building, a species, a chart convention — which you can then write into a description yourself.
Alt text questions.
What is alt text for?
It is read aloud by screen readers to people who cannot see the image, and it displays if the image fails to load. Search engines also use it, which is why it gets discussed as an SEO tactic, and that is the secondary purpose rather than the primary one. Writing it well for the first reader serves the second automatically.
How long should alt text be?
Concise, with enough detail. There is no universal character limit. Describe the essential information or action, and use adjacent text for complex explanations. If an image needs more explanation, put it in a caption or the page text where everyone benefits.
What about decorative images?
Give them an empty alt attribute, alt="", so screen readers skip them. This is the rule most guides omit and it matters: describing a background flourish interrupts the page with noise. Leaving the attribute off entirely is worse, because some readers then announce the filename instead.
Should I put keywords in alt text?
Only words that genuinely describe the image. Keyword stuffing here is not a neutral tactic that annoys a crawler — it is a string of search terms read aloud to a person who needed a description. It is also ineffective, since search engines have long discounted it.
Does alt text help SEO?
Yes, modestly, and mainly for image search. It gives search engines a description of content they cannot otherwise read. The useful framing is that writing accurate, specific alt text for accessibility produces the SEO benefit as a side effect, whereas writing it for search produces neither.
Can AI write alt text from my image?
Assistants with vision describe images accurately and cannot know why the image is on your page, which is what decides what to describe. Treat their output as a first draft to cut down rather than a finished attribute — and verify it, because an inaccurate description is worse than none, since the person relying on it cannot check.
Which assistant is best for alt text?
Claude tends to identify what an image conveys rather than only what it contains, which is the harder half of the job, though it runs long. Gemini is efficient for product photography. DeepSeek is best on charts and diagrams. Grok is the poor fit, because personality is friction in an attribute read aloud in sequence.
What about charts and infographics?
These are the hardest case. The information in a chart is the point, so a description saying 'bar chart showing sales data' conveys nothing. Either state the finding the chart shows in the alt text, or put the underlying figures in the page as a table, which is better for everyone.
Do images of text need alt text?
They need the text transcribed, and ideally they should not exist. An image of text is inaccessible, unsearchable, and breaks when it scales. If the image cannot be avoided, the alt text has to carry the words exactly.
Is my text stored?
The document is attached to your account so you can return to it, and you can delete it whenever you like. It is not used to train anything.