How long should alt text be?

Alt text should be 125 characters or fewer. Most screen readers cut off alt text beyond this length, which means visually impaired users miss critical information. Aim for a concise, descriptive phrase that captures the image's purpose and context within the surrounding content.

Should every image have alt text?

Every meaningful image should have alt text. Decorative images - like background patterns, dividers, or purely aesthetic elements - should use an empty alt attribute (alt='') so screen readers skip them entirely. If an image conveys information or context, it needs descriptive alt text.

Should you put keywords in alt text?

Yes, but only when the keyword naturally describes the image content. If you have a photo of someone writing a blog post, including 'content marketing' in the alt text makes sense. Stuffing keywords into alt text that do not relate to the image hurts both accessibility and SEO.

Does alt text help with Google Image Search rankings?

Alt text is the single most important factor for Google Image Search rankings. Google explicitly states that alt text helps them understand image content and match it to relevant image search queries. Pages with well-optimized alt text see significantly more traffic from Google Images.

What is the difference between alt text and title text for images?

Alt text describes the image content for search engines and screen readers - it is essential for accessibility and SEO. Title text creates a tooltip that appears when users hover over an image. Title text has minimal SEO value and is optional, while alt text is functionally required.

How to Optimize Image Alt Text for SEO

Image alt text - also called alternative text or alt attributes - is the written description embedded in an image's HTML code that tells search engines and assistive technologies what the image depicts. According to WebAIM's 2024 accessibility analysis, missing or inadequate alt text is the second most common accessibility error on the web, found on 54.5% of all home pages surveyed. For SEO, Google has confirmed that alt text is a primary signal used to understand and index images, making it critical for both search visibility and compliance with accessibility standards.

Optimizing alt text sits at the intersection of accessibility, user experience, and search engine optimization. When done correctly, it improves your rankings in Google Image Search, strengthens your page's topical relevance, and ensures your site is usable by people who rely on screen readers.

Why Does Alt Text Matter for SEO?

Alt text serves as a direct communication channel between your images and search engine crawlers. Since search engines cannot "see" images the way humans do, they depend on alt text to understand visual content.

Google Image Search traffic. According to SparkToro's 2024 search traffic study, Google Images accounts for roughly 22% of all Google searches. Pages with properly optimized alt text appear in image search results, driving an additional traffic stream that many sites neglect entirely.

Page relevance signals. Alt text contributes to the overall topical relevance of your page. When your images include alt text that aligns with the page's target keywords and content theme, it reinforces to Google what the page is about.

Accessibility compliance. The Web Content Accessibility Guidelines (WCAG) require alt text on all non-decorative images. According to the World Health Organization, over 2.2 billion people globally have a vision impairment, making alt text essential for reaching a significant portion of internet users. Beyond legal compliance, accessible sites tend to rank better because Google rewards good user experience signals.

How Do You Write Effective Alt Text?

Writing strong alt text follows a straightforward framework:

Describe the image content accurately. Start with what the image actually shows. A photo of a marketing team reviewing analytics on a whiteboard should say exactly that - not "marketing" or "team photo" alone.

Include relevant keywords naturally. If the image relates to your page's topic, incorporate target keywords in a way that genuinely describes the image. For a screenshot of Google Search Console data, writing "Google Search Console performance report showing organic click trends" is both descriptive and keyword-relevant.

Be specific but concise. Aim for 8 to 15 words that capture the essential visual information. Vague descriptions like "chart" or "infographic" waste the opportunity. Instead, describe what the chart specifically shows.

Skip "image of" or "photo of" prefixes. Screen readers already announce that an element is an image, so leading with "image of" is redundant and wastes character space.

Consider the surrounding context. Alt text should complement - not repeat - the surrounding text. If your paragraph already describes a process in detail, the alt text for an accompanying diagram can focus on what the diagram adds.

What Are Common Alt Text Mistakes?

Several recurring mistakes undermine alt text effectiveness:

Keyword stuffing. Cramming multiple keywords into alt text is a Google-documented spam signal. Writing "SEO tips SEO strategy SEO tools SEO optimization" as alt text provides no useful description and risks penalties.

Leaving alt text empty on meaningful images. This is the most common error. Every image that conveys information or supports the content needs descriptive alt text. Empty alt attributes should only be used for purely decorative images.

Using file names as alt text. Descriptions like "IMG_4582.jpg" or "screenshot-2026-02-15" tell search engines and users nothing about the image content.

Writing alt text that is too long. Screen readers typically truncate alt text after 125 characters. Descriptions longer than this get cut off mid-sentence, creating a poor experience for visually impaired users.

Identical alt text across multiple images. Each image on a page shows something different, so each should have unique alt text. Duplicate alt text looks like automated or low-effort optimization to search engines.

How Should You Optimize Alt Text for Different Image Types?

Different image types require different alt text approaches:

Product images. Include the product name, key visual attributes, and distinguishing features. "Navy blue merino wool crew neck sweater with ribbed cuffs" is far more useful than "sweater."

Screenshots and UI images. Describe what the screenshot shows and why it is relevant. "Conbersa dashboard showing multi-account posting schedule for three LinkedIn profiles" tells both search engines and screen reader users exactly what they are looking at.

Charts and graphs. Summarize the key data point or trend. "Bar chart showing 47% increase in organic traffic after alt text optimization" conveys the insight the image delivers.

Decorative images. If an image is purely decorative, use an empty alt attribute (alt="") so screen readers skip it entirely.

How Does Alt Text Fit Into a Broader Image SEO Strategy?

Alt text is the foundation of image SEO, but a complete strategy also includes descriptive file names (rename "image1.png" to "content-marketing-funnel-diagram.png"), image compression for faster load times, and structured data markup for product or recipe images.

When alt text optimization is combined with these technical practices, the impact compounds. Pages with fully optimized images consistently outperform those with unoptimized visuals in both standard search and image search results. Aligning your alt text with search intent ensures every image reinforces the page's relevance for its target queries.