What Is Image Alt Text and Why Does Every Picture on Your Website Need One?
If your audit flagged "missing alt text," it caught something invisible to you but not to Google or a screen reader: every photo, logo, and screenshot on your site has a hidden description field, and on most small business sites, it's empty. That gap costs two things at once - a ranking signal and a real visitor's ability to know what's on the page.
What alt text actually is
Alt text - short for "alternative text" - is a short written description attached to an image's HTML, using the alt attribute: <img src="storefront.jpg" alt="Front entrance of Smith's Hardware on Main Street">. It never shows up visually on the page next to the image. It only surfaces in three situations: a screen reader reads it aloud instead of the image, a browser displays it as placeholder text if the image fails to load, and Google reads it to understand what the image contains.
<img src="IMG_4821.jpg">
<img src="IMG_4821.jpg" alt="Licensed plumber repairing a water heater in a Charlotte home">
Why Google can't just "see" the picture
Google's crawler reads code, not photographs. It has no idea what a business's storefront, product, or team photo actually shows unless something tells it - and alt text is the primary, most reliable way that information reaches Google. Without it, an image contributes nothing to the page's relevance for the words a customer might search, and it earns zero chance of showing up in Google Image Search, which is a real source of traffic for local businesses whose customers search things like "charlotte water heater repair" and browse the image results before clicking through.
File names don't rescue this. Most images uploaded from a phone or camera keep a name like IMG_4821.jpg or photo (3).png - meaningless to Google and to anyone reading raw code. Alt text is the one place a small business can plainly say, in words Google actually indexes, what each image shows and why it's on that page.
Why it matters more for a real visitor than most people realize
A screen reader announces an image by reading its alt text out loud in place of showing it. With no alt text, most screen readers fall back to announcing the raw file name - "IMG 4821 JPEG" - or skip the image silently, as if it were never there. For a blind or low-vision visitor, that can mean missing exactly the information a business most wants a customer to see: a phone number baked into a graphic, an address on a map screenshot, a menu photographed instead of typed out, or the one product photo that would have answered their question.
This isn't a rare edge case. Screen reader usage among U.S. adults with vision difficulty is a meaningful, measurable slice of web traffic - and it costs nothing to serve them correctly once you know to do it. The fix is also permanent: once alt text is written, it works for every future visitor and every future crawl, with no ongoing cost.
How to write alt text that actually works
Describe what the image shows, plainly
Write what's actually in the picture, the way you'd describe it to someone on the phone who can't see it. "Front entrance of Smith's Hardware on Main Street" beats "hardware store" - specific and useful beats vague and generic, the same principle as good link text.
Skip "image of" and "picture of"
Screen readers already announce that it's an image before reading the alt text, so starting with "image of a plumber repairing..." makes a visitor hear "image, image of a plumber repairing..." - redundant and slightly worse, not more helpful.
Keep it under about 125 characters
Some screen readers truncate longer alt text. A short, specific sentence covers what's needed; save the extra detail for the surrounding page text, not the alt attribute.
Use an empty alt="" for purely decorative images
A background texture, a spacer graphic, or an ornamental divider that adds zero information should get alt="" - not "decorative image" and not a missing attribute. An empty alt attribute tells a screen reader to skip the image silently, which is the correct, quieter experience; leaving the attribute off entirely can make some screen readers announce the file name instead, the exact noise this is meant to avoid.
How to check your own site in under a minute
Right-click any image on your site in Chrome and choose "Inspect." Look at the <img> tag in the code panel that opens: if there's no alt="..." at all, or it's empty on an image that clearly isn't decorative (a product shot, a staff photo, a screenshot with real information in it), that's the pattern to fix. Repeat on your homepage and your two or three most important pages - that alone usually surfaces the worst offenders.
How the free audit catches this
Missing alt text is one of the checks in our free audit, run alongside speed, mobile-friendliness, and the rest of our website audit checklist. It comes back as a medium-impact finding naming how many images on the page have no alt text - a real count from the actual page, not a generic warning.
Frequently asked questions
What is image alt text?
Alt text (short for "alternative text") is a short written description of an image, added to the image's HTML alt attribute. It never appears visually on the page - it only surfaces when an image can't be seen: a screen reader reads it aloud, a browser shows it if the image fails to load, and search engines read it to understand what the image contains.
Why does missing alt text hurt SEO?
Google cannot see a photo the way a person can. It relies on the alt text, surrounding text, and file name to understand what an image shows and what page it belongs on. Without alt text, an image is effectively invisible to Google - it earns no image-search traffic and hands the page no relevance signal from that image at all.
Why does missing alt text matter for accessibility?
A screen reader announces an image by reading its alt text out loud. With no alt text, most screen readers announce the raw image file name instead - something like "IMG 4821 JPEG" - or skip the image entirely. For a blind or low-vision visitor, that can mean missing a phone number, an address, or a product photo that only exists as an image on the page.
How do I write good alt text?
Describe what the image actually shows, in plain language, in under about 125 characters, without starting with "image of" or "picture of" (screen readers already announce it as an image). If the image is purely decorative and adds no information, use an empty alt attribute (alt="") instead of describing it, so screen readers skip it silently rather than reading out noise.
Does every image need alt text?
Every image that conveys information needs it - product photos, staff photos, logos, screenshots, anything with a phone number or address baked into the image itself. Purely decorative images (background textures, spacer graphics, ornamental dividers) should get an empty alt="" instead, which is different from having no alt attribute at all and is the technically correct choice for that case.
The cheapest way to find out
Run the free audit below. We check your image alt text along with speed, SEO, mobile-friendliness, and accessibility, using the same tooling Google itself uses, and email you a plain-English report naming exactly how many images need a description. If something needs fixing, it's a flat $149 for your fixable speed/image/SEO/broken-link issue, or $299 for everything, with before-and-after proof once it's done.