How to Write ALT Text That Actually Works for Accessibility and SEO

ALT text guides often frame accessibility as a side benefit of SEO-focused optimization. It's worth flipping that framing: ALT text exists primarily as an accessibility requirement for screen reader users — the SEO benefit is real but secondary. Getting the accessibility use case right also produces the best SEO outcome, so there's no tension between the two done properly.

What ALT text is actually for

A screen reader announces ALT text in place of an image for users who are blind or low-vision. If the ALT text doesn't convey what a sighted user would understand from the image, it's failing its primary job — regardless of how well it's "optimized" for search engines.

Before/after: what good ALT text actually looks like

Bad (unhelpful for both accessibility and SEO): alt="image1" or alt="photo"

Bad (keyword-stuffed, unhelpful for accessibility): alt="digital marketing agency Vizag SEO social media marketing services best agency"

Good (descriptive, serves both purposes): alt="Team reviewing a social media content calendar on a whiteboard"

The good version tells a screen reader user what's actually in the image, and it naturally includes relevant context without keyword stuffing — which search engines now actively penalize rather than reward.

A concrete rewrite process

Describe what's actually in the image, as if explaining it to someone who can't see it — specific enough to convey meaning, not padded with keywords that don't describe the image.
Skip "image of" or "picture of" — screen readers already announce that it's an image; adding it is redundant.
Keep it concise — a sentence or short phrase is usually enough; there's no fixed universal character limit, but brevity that still conveys meaning is the goal.
For infographics/charts, describe the key insight or data point, not just "a chart" — this is where ALT text does the most SEO and accessibility work simultaneously, since charts often can't be understood any other way by a screen reader.
Decorative images (purely visual, no informational content) should have empty ALT text (alt=""), not a forced description — marking them as decorative is correct practice, not a missed opportunity.

A free audit workflow

Run your site through a free accessibility checker (browser extensions like WAVE, or Chrome's built-in Lighthouse accessibility audit) to find images with missing or empty ALT text that shouldn't be empty.
Prioritize product/service images, infographics, and any image conveying information (not purely decorative) first.
Rewrite in batches by page type rather than one at a time — service pages first, since these carry the most SEO and conversion weight.
Re-run the audit after fixes to confirm nothing was missed.

What ALT text can't fix on its own

ALT text is one signal among several for image discoverability — filename (social-media-planning-session.jpg beats IMG_4821.jpg), surrounding page content, and captions all contribute too. Fixing ALT text alone without addressing generic filenames leaves meaningful signal on the table.

FAQ

Do all images need ALT text? Informational images (photos, infographics, charts) need descriptive ALT text. Purely decorative images (background textures, spacers) should have empty ALT text (alt="") rather than a forced, meaningless description.

Does ALT text actually help with voice search specifically? It contributes to overall image and page context, which voice assistants and AI-answer systems can draw on — but it's a supporting signal within good structured content and local SEO practice, not a standalone voice-search tactic.

Should ALT text include keywords? Only where the keyword genuinely describes the image content — never as a stuffed list of target keywords unrelated to what's actually shown, which hurts both accessibility and modern SEO evaluation.

Want an ALT text and accessibility audit for your site?

Xscade's digital marketing agency in Vizag runs accessibility and image SEO audits as part of every technical SEO engagement. Get in touch for a check on your current site.