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Alt text generator
Give the subject of the image, your target keyword, and a snippet of context. We'll suggest 4 alt-text variations, each within the 125-character sweet spot.
a product dashboard showing keyword rankings and traffic over 90 days, captured for an article on AI SEO
Annotated screenshot: a product dashboard highlighting showing keyword rankings and traffic over 90 days, for a guide on AI S
a product dashboard — showing keyword rankings and traffic over 90 days (AI SEO)
Illustration of a product dashboard showing keyword rankings and traffic over 90 days; relevant to AI SEO
Quick answer
What is an alt text generator for images?
Alt text is the written description in an image's alt attribute - what a screen reader announces, and what displays if the image fails to load. This alt text generator free tool takes three inputs from you (the subject of the image, your target keyword, and a line of context about what is notable in it) and returns four phrasings, each trimmed to roughly 125 characters. You pick the one that describes the image most accurately, then edit it.
Alt text is an accessibility feature first
A screen reader encountering an image announces the alt attribute in the flow of the page - typically as 'graphic' or 'image' followed by your text. Which means alt text is read aloud, in sequence, by a person trying to follow your argument. That single fact settles most alt-text questions.
Describe what the image conveys in this context, not everything visible in it. A chart's alt text should state what the chart shows, not that it is a chart with blue bars. Skip 'image of' and 'photo of' - the screen reader has already said so, and repeating it wastes the listener's time. Aim for around 125 characters, which is where several screen readers and authoring tools start truncating and, more usefully, roughly the length beyond which a spoken description stops being a caption and becomes a paragraph.
Decorative images, and when to leave the keyword out
If an image adds nothing a reader would miss - a divider, a background flourish, an icon sitting next to text that already says the same thing - give it an empty alt attribute: alt="". That is not the same as omitting the attribute. An empty alt tells assistive technology to skip the image silently; a missing alt often makes a screen reader read out the filename instead, which is worse than saying nothing.
On the keyword: include it only when it honestly describes the image. If the article targets 'keyword research tool' and the screenshot shows a keyword research tool, the phrase belongs there naturally. If the image is a stock photo of a laptop on a desk, forcing the phrase in produces a description that is both useless to a blind reader and a textbook example of what search-engine image guidance warns against. One image per page carrying the exact target phrase is plenty; the rest should simply be accurate.
The rest of image SEO
Alt text is one signal among several that tell search engines what an image depicts. Google Images is a real discovery surface, and the pages that do well there get the surrounding details right too.
- File names: keyword-research-dashboard.png tells a crawler something; IMG_4821.png does not. Rename before upload - it is the cheapest win available.
- Captions are visible to everyone and are read by sighted users far more often than body copy. Alt text and caption serve different audiences, so do not paste the same string into both.
- Surrounding text matters: the paragraph an image sits in helps establish its subject.
- Serve modern formats at sensible dimensions and set explicit width and height - image weight is usually the largest contributor to a poor Largest Contentful Paint score.
- Include images in an image sitemap or your main sitemap if image search matters for your niche.
Where this data comes from
The generator is deterministic and runs in your browser: it composes four sentence patterns from the subject, keyword, and context you supply, collapses whitespace, and truncates each result to 125 characters. It does not look at your image file - no vision model, no upload, no analysis of pixels. It is a fast way to draft four honest phrasings from facts you already know, and the output is a starting point you are expected to edit against the actual image.
Frequently asked questions
How long should alt text be?
Around 125 characters is the practical ceiling. Several screen readers and authoring tools truncate near that length, and a description longer than a sentence stops being useful when it is read aloud mid-paragraph. If an image genuinely needs a long explanation - a complex chart or diagram - put that explanation in the visible text or a caption and keep the alt attribute to a summary.
Should I put my keyword in every image's alt text?
No. Include it only where it accurately describes the image. Repeating a target phrase across every image on a page is a recognised over-optimisation pattern and it makes the page hostile to screen-reader users, who hear the same phrase over and over. One accurate keyword-bearing description plus honest text everywhere else is the right shape.
What is alt text for decorative images?
Use an empty alt attribute: alt="". This tells assistive technology to skip the image entirely, which is what you want for dividers, background textures, and icons duplicating adjacent text. Do not omit the attribute - a missing alt frequently causes screen readers to announce the file name instead, which is noise the user has to sit through.
Does alt text help SEO?
Yes, in two ways. It is a primary signal for what an image depicts, which affects Google Images ranking, and it contributes context about the page to systems that read it. The accessibility benefit is the larger and more certain one. Write the description a blind reader would need and the search benefit comes with it - the reverse rarely works.
Is the file name as important as the alt text?
It is a smaller signal but a genuinely free one. Search engine image guidance recommends descriptive file names, and renaming a file before upload takes seconds. Use hyphens between words, keep it short and literal, and stop there - a file name crammed with keywords is as unhelpful as a stuffed alt attribute.
What is the difference between alt text and a caption?
Alt text is read by screen readers and shown when an image fails to load; it exists for people who cannot see the image. A caption is visible text below the image that everyone reads, and it usually adds interpretation or a source. Different audiences, different jobs - write both separately rather than duplicating one into the other.
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