Image Alt Text Generator — accessible, purpose-built alt attributes

The image alt text generator on this page is a writing helper, not an AI vision tool — it doesn't look at your actual image, because it can't. What it does is take your plain description of what the image shows, along with the purpose you select, and assemble it into a properly structured alt attribute that follows accessibility rules first and SEO best practice second, in the order that actually matters.

Arb Digital audits alt text on nearly every site we take on for SEO work, and the two most common problems are opposite extremes: images with no alt text at all, and images with alt text so stuffed with keywords that it reads like spam to anyone using a screen reader. This tool exists to help you avoid both.

What This Alt Text Generator Does

You describe what the image shows in plain language, pick the purpose it serves on the page — informative, decorative, a functional button or icon, a linked image, or an infographic — and optionally add a target keyword and page context. The generator then assembles an alt attribute using the correct structure for that purpose. A decorative image gets an empty alt attribute, exactly as accessibility guidelines require. A functional image, like a button or icon, gets alt text describing the action it performs, not what it visually looks like. An informative image gets a clear description of its content, with your keyword woven in only if it fits naturally. A linked image gets alt text describing the destination, since that's what a screen reader user needs to decide whether to click. An infographic gets a description plus a pointer to a longer text explanation, since alt text alone can't carry a data-dense image's full information.

The tool also checks your result against a simple do/don't checklist and reports how many accessibility guidelines it satisfies, along with a live character count against the roughly 125-character point where many screen readers stop reading or truncate the attribute.

How to Use It

1. Describe the image. Write what's actually in it, plainly — no need for full sentences yet.
2. Select the purpose. This is the single most important choice; it changes the entire structure of the output.
3. Add a keyword, if relevant. Only if the image genuinely relates to a keyword you're targeting on that page — don't force it.
4. Add page context, if useful. Helps disambiguate an image that could otherwise read as generic.
5. Click Generate Alt Text. Review the assembled attribute, the character count, and the checklist below it.
6. Copy it straight into your image's alt attribute. No further editing needed unless something about your specific image differs from the description you gave.

Accessibility Comes First, SEO Comes Second

This is the single most important thing to understand about alt text, and it's the principle this whole tool is built around: alt text exists primarily so that people using screen readers — people who are blind or have low vision — can understand what's on the page. The W3C Web Accessibility Initiative's tutorial on images lays out exactly this hierarchy — the alt attribute's job is to convey the same information or function the image conveys visually, and the specific wording depends entirely on what role that image plays on the page. SEO benefit is real but secondary: Google uses alt text to understand and index images for Google Images and general context, but it has always warned against writing alt text as a place to cram keywords rather than to genuinely describe the image.

That ordering has a direct, practical consequence: decorative images — a background texture, a divider graphic, a purely visual flourish that adds nothing informational — should have an empty alt attribute, written as alt="", not omitted entirely and not filled with a description. An empty alt attribute tells screen readers to skip the image entirely, which is the correct, helpful behavior, since describing a meaningless decorative graphic just wastes a blind user's time and adds noise to their reading experience. Leaving the alt attribute off completely, by contrast, can cause some screen readers to read out the image's file name instead — something like "IMG-2847-final-v2.jpg" — which is worse than saying nothing at all.

Why Keyword-Stuffed Alt Text Backfires

Writing alt text like "best digital marketing agency SEO services affordable digital marketing near me" is both a ranking risk and genuinely hostile to a blind visitor trying to understand your page. Google's own Google Images SEO documentation explicitly advises writing alt text that describes the image accurately and naturally, warning against keyword stuffing as a practice that can hurt rather than help how an image ranks. For a screen reader user, that same stuffed alt text is read aloud in full — imagine having a keyword-jammed run-on sentence read to you every time you encounter an image on a page, instead of a clear, useful description. Good alt text describes what matters about the image for the context it appears in, includes a keyword only when it fits naturally into that honest description, and stays concise enough to be genuinely useful when read aloud.

The 125-character guideline this tool checks against isn't an official spec, but it's a widely used practical benchmark, because a number of screen readers and browser combinations historically truncated alt text around that length. Staying under it means your description is far more likely to be read in full rather than cut off mid-sentence, which matters most for the informative and functional categories where the full description carries real meaning.

Writing Alt Text for Each Purpose Type

Each purpose this generator supports calls for a genuinely different structure, not just a different tone. An informative image — a standalone photo or illustration that conveys content — needs a description of what's actually shown, written as if you were describing it to someone who can't see it, with a natural keyword mention only if it truly fits. A decorative image gets nothing but an empty attribute, full stop, regardless of how interesting the image might look to a sighted visitor. A functional image — a button, a search icon, a hamburger menu icon — needs alt text describing the action it performs when clicked, such as "search the site" or "open the main menu," not a visual description of the icon's shape. A linked image needs alt text describing where the link goes or what happens next, since that's the decision-relevant information for someone deciding whether to click. An infographic or chart needs a concise summary of what it shows, ideally paired with a text equivalent elsewhere on the page, since no alt attribute can realistically convey a dense chart's full data in a sentence or two.

Common Alt Text Mistakes to Avoid

• Leaving alt attributes off entirely. Some screen readers fall back to reading the file name, which is worse than an empty attribute.
• Writing a description for decorative images. Decorative images should get alt="", not a description of the decoration.
• Keyword stuffing. "Best cheap SEO services affordable digital marketing" as alt text helps no one and can hurt image search rankings.
• Starting with "image of" or "picture of." Screen readers already announce that it's an image — saying so again wastes the reader's time.
• Describing a button's appearance instead of its function. "Blue arrow icon" tells a user nothing useful; "next page" does.
• Writing alt text over 125 characters for critical images. Longer descriptions risk truncation on some screen reader and browser combinations.

Related Free Tools From Arb Digital

Keep your on-page SEO consistent across every image and link. Vary your outbound and internal link text with the anchor text generator, widen your topical coverage with the LSI keyword generator, write clean URLs with the slug generator, build titles and meta descriptions with the meta tag generator, and promote new posts with the hashtag generator. Browse everything in our free online tools hub.

Frequently Asked Questions

This tool is a writing helper based on accessibility and SEO guidelines — it does not analyze your actual image. Always confirm the generated text truly matches what your image shows before publishing.