What an alt text generator does
An alt text generator takes an image URL or upload, the page topic or context, and an audience preference-general, screen-reader-first, or SEO-first-then produces three alt-text variants. The short variant stays under 125 characters and focuses on the essential subject. The medium variant adds spatial or relational context in 125 to 150 characters. The descriptive variant goes to 200 characters and includes details about color, layout, emotion, or branding when those details matter for comprehension or discovery.
The generator also runs a decorative-image check. If the image is purely aesthetic-a background gradient, a decorative border, a stock photo of hands on a keyboard that adds no information-the tool flags it and recommends alt="" (empty alt attribute) instead of descriptive text. Screen readers skip images with empty alt, which reduces noise for users navigating by headphone.
WCAG 2.2 compliance requires that all non-decorative images have alt text, that the alt text conveys equivalent information to the image, and that it does not exceed 150 characters unless the image is complex (charts, diagrams, infographics). Our WCAG check flags three violations: missing alt, alt text that is too generic ("image" or "photo"), and alt text that starts with "image of" or "picture of" (screen readers already announce "image," so the prefix is redundant).
How to use this alt text generator
- Paste the Image URL or drag an image file into the upload box. We support JPG, PNG, WEBP, and SVG.
- Fill Page topic / context with a one-sentence description of the article or page where the image appears-"article about first-time home buying," "landing page for project management software," "product photo on a sneaker category page."
- Pick Primary audience. Choose "General" for balanced SEO and accessibility. Choose "Screen-reader-first (accessibility)" to prioritize clarity for non-visual users over keyword inclusion. Choose "SEO-first" to emphasize product names, brand terms, and discoverable phrases when the image is primarily for search traffic.
- Hit Generate alt text. Three variants appear with character counts. Each is copy-ready.
- Pick the variant that fits your context. Use short for simple product shots. Use medium for most blog hero images. Use descriptive for infographics, charts, or images that convey data or complex layouts.
- Copy and paste into your CMS. In WordPress, paste into the "Alternative Text" field in the media library. In HTML, paste as
alt="…"inside the<img>tag. In Next.js, use thealtprop on the<Image>component.
For bulk mode, click "Switch to bulk" at the top of the form. Paste up to ten image URLs, one per line, or drag a folder of images. Fill the page context once. Hit generate. The output is a table with one row per image: thumbnail, short alt, medium alt, descriptive alt. Copy the table or export as CSV for WordPress bulk import.
Why alt text matters for accessibility and SEO
Alt text serves two masters: screen-reader users who cannot see images, and search engines that cannot interpret image content without text. A 2023 WebAIM survey of one million home pages found that 58% of images either had missing alt text or alt text that failed WCAG guidelines-"image," "IMG_1234.jpg," or keyword-stuffed gibberish.
Three reasons to write alt text correctly.
Legal compliance. WCAG 2.1 Level AA is the accessibility standard required by the Americans with Disabilities Act, the European Accessibility Act, and equivalent laws in Canada, Australia, and the UK. Missing or incorrect alt text is the second most common ADA website lawsuit trigger after keyboard navigation failures, according to a 2024 report by UsableNet covering 4,600 digital accessibility lawsuits. E-commerce and financial services sites are the most frequent targets.
Screen-reader usability. Fifteen percent of U.S. adults report some form of vision disability, per the CDC. Screen readers like JAWS, NVDA, and VoiceOver read alt text aloud when a user tabs to an image. If the alt says "image," the user learns nothing. If the alt says "Graph showing 23% year-over-year revenue growth from Q1 2024 to Q1 2025," the user understands the content without seeing it.
Image search traffic. Google Images drives 22% of all web searches, per data from SparkToro. Alt text is the primary text signal Google uses to rank images. A product photo with alt text "blue running shoe" ranks for "blue running shoe." The same photo with alt text "IMG_5391.jpg" ranks for nothing. A 2022 study by Moz found that adding descriptive alt text to previously un-alted images increased image-search impressions by an average of 35% within 90 days.
Alt text vs. title attribute vs. caption vs. file name
These four terms describe different image metadata. Each has a distinct purpose.
Alt text is the alt attribute inside the <img> tag. Screen readers announce it. Google indexes it. It is required for accessibility. If the image fails to load, browsers display the alt text in place of the image. Maximum practical length: 125 to 150 characters for simple images, 200 for complex ones.
Title attribute is the title attribute inside the <img> tag. Browsers display it as a tooltip on hover. Screen readers mostly ignore it. Google ignores it. Title is optional and rarely necessary. Do not use title as a substitute for alt.
Caption is visible text displayed below or next to the image, typically inside a <figure> and <figcaption> tag. Captions provide context or credit. Screen readers read captions aloud in addition to alt text. If the caption fully describes the image, the alt text can be shorter or empty. If the caption is editorial ("This approach changed everything"), the alt still needs to describe what the image shows.
File name is the image's URL slug-"blue-running-shoe.jpg" vs "DSC_1234.jpg". Google reads file names as a weak ranking signal. Descriptive file names help SEO marginally, but alt text matters far more. Rename files before upload if your CMS allows it, but do not skip alt text because the file name is descriptive.
When you optimize an image, write alt text first. Add a caption if the image needs editorial context. Rename the file if it is currently a random string. Skip the title attribute unless you have a specific tooltip use case.
Common mistakes
- Writing "image of" or "picture of" at the start. Screen readers already announce "image" before reading the alt. Starting with "image of" produces "image image of blue shoe." Start with the subject: "Blue running shoe on white background."
- Keyword stuffing. Alt text like "best running shoes cheap running shoes buy running shoes online" is spam. Google penalizes it. Screen-reader users hear gibberish. Write for humans first. One natural keyword mention is enough.
- Using the same alt text for every image on a page. If five product photos all have alt="product photo," screen-reader users cannot distinguish them. Describe what makes each image unique: "Front view of blue running shoe," "Side profile showing sole tread," "Close-up of lace eyelets."
- Leaving decorative images with descriptive alt. Background patterns, decorative dividers, and whitespace images should have
alt=""so screen readers skip them. Describing a decorative swoosh graphic as "blue curved design element" adds no value and slows navigation. - Writing essay-length alt text. Screen readers speak at 150 to 250 words per minute. A 300-character alt takes 10 seconds to announce. Users navigating a page with 20 images spend three minutes listening to descriptions. Keep alt under 150 characters unless the image is a chart or infographic that requires detail.
Advanced tips
- Use the medium variant as your default. Short works for straightforward product shots. Descriptive works for complex diagrams. Medium balances accessibility and SEO for most blog and landing-page images.
- Match alt text specificity to the page's topic. If your article is "How to tie running shoes," the hero image alt should describe the knot style-"Runner tying a double knot on blue running shoe." If the page is a category listing for running shoes, the same image's alt should emphasize the product-"Blue mesh running shoe with white sole."
- Run the generator on your existing images. Export your site's image URLs from your CMS or crawl with Screaming Frog. Paste the list into bulk mode. Review the generated alt text. Update images that currently have missing or generic alt.
- Test alt text with a screen reader. Install NVDA (Windows) or enable VoiceOver (Mac). Navigate your page by pressing the Tab key. Listen to what the screen reader announces. If the alt text is confusing or repetitive, revise it.
- Add structured data for images used in how-to steps, recipes, or product listings. Use the
"image"property in JSON-LD schema to reference the image URL and associate it with the structured content. Google displays images inline with how-to rich results when the schema is present. - Avoid redundancy between caption and alt. If the caption says "Graph showing revenue growth," the alt should describe the data-"Bar chart with five bars, showing revenue increasing from 2M in 2022 to 3.5M in 2026." The alt provides the detail the caption omits.
Once alt text is in place, the next step is usually checking that the rest of the page's metadata is correct. Feed your page URL into our website metadata checker to validate title, meta description, OG tags, Twitter card, and schema in one scan. If you are optimizing a full article, use the meta description generator to write the SERP snippet and the SEO title generator to produce matching title tags with live Google preview. When planning content that includes images, use the content brief generator to map out the full structure before writing.