What alt text is
Alt text is the alternative description in an image's HTML. When the image cannot load or a reader announces it, that text stands in. It is not a caption and not a place for keywords — it is a concise description of what the image conveys and why it matters in context.
Why it matters for accessibility and SEO
For accessibility, alt text is how blind and low-vision users perceive visuals; missing it leaves a blank. For SEO, image search and general understanding both use alt text to place your picture in context. A short, accurate description serves both audiences at once, and it is one of the cheapest improvements you can make to a page.
When to write it
- Every content image that carries meaning, not decoration.
- Product photos where the description helps shoppers and search.
- Charts and graphs where the takeaway should be stated in words.
- Infographics summarized so the point survives without sight.
- Logos and icons where function (not brand) is the message.
- Tutorial screenshots where the alt names the step shown.
How to write good alt text
State what the image shows and why it matters, in one sentence, without "image of" or "picture of" padding. If the image is decorative, mark it empty rather than forcing words. Lead with the subject, then the detail a reader needs. Because Glint's helpers run in your browser, you can draft alt text without uploading your image to a third party.
A step-by-step method
- Identify the subject — what is actually in the frame.
- State the context — why this image is on the page.
- Add one detail — color, size, result, or action.
- Drop the filler — no "image of", no keyword stuffing.
- Mark decorative images empty so readers skip them.
A worked example
| Image | Bad alt | Good alt |
|---|---|---|
| Product shot | img1 | "Blue ceramic coffee mug on a wooden table, 12 oz" |
| Chart | chart | "Line chart: monthly signups rose from 200 to 900 in Q2" |
| Decorative divider | — | (empty alt) |
The good versions name the subject and the relevant detail, which is exactly what a reader or search engine needs.
Good vs bad alt text compared
| Approach | Example | Why |
|---|---|---|
| Descriptive | "Bar chart of 2025 revenue by quarter" | Useful and specific |
| Keyword-stuffed | "buy mug cheap mug best mug" | Spammy, unhelpful |
| Padding | "image of a picture of a mug" | Says nothing |
A quick scenario: a small shop owner
A shop owner adds ten product photos to a new collection page and leaves alt blank by default. A friend using a screen reader says the page is "silent" on images. Using a free alt-text helper, the owner writes one sentence per photo: color, material, size.
The page becomes navigable for everyone, and the product appears in image search for specific terms like "blue ceramic mug 12 oz". No account, no upload of product shots to a random site. Alt text becomes a publish-step checkbox, not an afterthought, and the owner templates the pattern for future drops.
The habit compounds. Every upload ships described, the store becomes more usable, and image search slowly sends a trickle of ready-to-buy visitors. The cost was a sentence per photo, paid once.
Common mistakes
Keyword-stuffing alt text is the main one — "buy blue mug cheap mug best mug" helps no one and reads as spam. Another is writing "image" or "photo" as if that were information. Finally, describing decorative images wastes the reader's time; mark those empty instead, and never upload your catalog to a web tool just to generate alt text.
Who should use it (and who shouldn't)
Write alt text for every meaningful image on a public page. Skip it (use empty alt) for pure decoration. If you publish anything public, the answer is effectively always yes.
How it fits a writing toolkit
Glint's background remover is free and needs no account. Pair it with the SERP preview to see how your page, image and all, renders in search before you publish.
Frequently asked questions
Is alt text for SEO or accessibility? Both — it helps screen readers and gives search engines context for the image.
Should I include keywords in alt text? Only if they describe the image accurately; stuffing keywords hurts more than it helps.
What about decorative images? Mark them with empty alt so screen readers skip them gracefully.
Is a browser-based alt-text helper safe? Yes, when it runs on the page and needs no image upload or account.
Is the Glint background remover really free with no signup? Yes. It runs in your browser and requires no account.