Image ALT Tag Checker
Advanced image accessibility checker that analyzes ALT tags, provides SEO scores, and ensures WCAG compliance. Perfect for accessibility audits and SEO optimization.
Drag & drop HTML file here or click to upload
Upload HTML files for bulk analysis (max 5MB)๐ ALT Text Best Practices
Be Descriptive & Specific
Describe what's actually in the image. "Golden retriever puppy playing with red ball" is better than just "dog" or "image of dog".
Keep It Concise (125 chars)
Aim for under 125 characters. Screen readers often chunk text at this length. Long descriptions can be frustrating to listen to.
Decorative Images: alt=""
Use empty alt="" for purely decorative images. This tells screen readers to skip them. Never omit the alt attribute entirely.
Include Keywords Naturally
Incorporate relevant keywords when appropriate, but never keyword stuff. Context matters more than keyword density.
Don't Start with "Image of"
Screen readers already announce "image". Starting with "Image of" or "Picture of" is redundant and wastes characters.
Complex Images Need Description
For charts, graphs, or diagrams, provide a brief summary in alt and link to a detailed description nearby.
๐ ALT Text Examples
| Type | Example | Status | Explanation |
|---|---|---|---|
| Good | alt="Golden retriever puppy playing with red ball" |
โ Good | Descriptive, specific, under 125 chars |
| Poor | alt="img_12345.jpg" |
โ ๏ธ Poor | Filename as alt, no description |
| Missing | <img src="photo.jpg"> |
โ Missing | No alt attribute at all |
| Decorative | alt="" |
โ Good (decorative) | Empty alt for decorative images |
| Too Long | alt="..." (over 125 chars) |
โ ๏ธ Too Long | Difficult for screen readers |
๐ About Image ALT Tags
ALT (alternative) text is a written description of an image that serves multiple critical purposes. It's essential for accessibility, SEO, and user experience. The HTML specification requires all <img> tags to have an alt attribute, even if empty.
๐ฏ SEO Benefits of ALT Tags
- Google Images: ALT text is primary ranking factor for image search
- Page Relevance: Helps search engines understand image context
- Ranking Factor: Part of Google's page quality assessment
- Featured Snippets: Can appear in image-rich results
- Voice Search: Images can surface in voice search results
โ๏ธ Legal Requirements
WCAG 2.1 requires that all non-text content has a text alternative (Success Criterion 1.1.1 Level A). This is the minimum standard for accessibility compliance. Missing ALT tags have led to:
- ADA lawsuits against major retailers
- Department of Justice enforcement actions
- Section 508 compliance failures
- EU accessibility directive violations
๐ Industry Statistics
๐จ Image Types & ALT Requirements
| Image Type | ALT Example | Required? | Notes |
|---|---|---|---|
| Content Image | alt="Golden Gate Bridge at sunset" |
โ Yes | Describe the image |
| Decorative | alt="" |
โ Empty | Screen readers skip |
| Logo | alt="Company Name" |
โ Yes | Use company name |
| Button | alt="Search" |
โ Yes | Describe action |
| Icon | alt="" or label |
โ ๏ธ Depends | If functional, describe |
| Chart/Graph | alt="Bar chart: Sales 2023" |
โ Yes | Add detailed description nearby |
โ Frequently Asked Questions
ALT attribute is required and provides alternative text for screen readers and when images fail to load. It's essential for accessibility.
Title attribute is optional and provides additional information, typically shown as a tooltip on hover. It's not a substitute for ALT text and has limited accessibility support.
Always include ALT, use title only when needed for extra context.
Empty ALT (alt=""): Use for purely decorative images that don't convey information (background patterns, decorative borders, etc.). Screen readers will skip them.
Never omit ALT: Always include the alt attribute, even if empty. Omitting it entirely is invalid HTML and can cause some screen readers to read the image filename instead.
Google uses ALT text in several ways:
- Google Images: Primary ranking factor for image search results
- Page relevance: Helps Google understand image context
- Featured snippets: Can trigger image-rich results
- Voice search: Images may appear in voice search results
Good ALT text can significantly improve image search rankings and drive organic traffic through Google Images.
Aim for 80-125 characters. Here's why:
- Screen readers often split text at 125 characters
- Longer descriptions can be tedious to listen to
- Search engines prefer concise, relevant descriptions
- Most important information should come first
If you need longer descriptions for complex images, provide a brief summary in ALT and link to a detailed description nearby.
Only if the images are identical and serve the same purpose. For example, the same logo appearing multiple times can use the same ALT. However, for different images, unique ALT text is better:
- Helps screen readers distinguish between images
- Provides more value to search engines
- Avoids appearing as duplicate content
Our tool detects duplicate ALT text as a potential issue.