Image Alt Tag Checker

Free online image alt text checker to find images missing alt attributes on any webpage.
Ensure WCAG accessibility compliance, improve SEO, and enhance screen reader usability by identifying missing, empty, or poorly written image alt text.

About This Tool

The Image Alt Tag Checker analyzes any public webpage or pasted HTML to evaluate how images are using alt attributes. It helps website owners, developers, SEO professionals, and content creators ensure their images are accessible, search-engine friendly, and standards-compliant.

Alt text is essential for:

Visually impaired users using screen readers
Search engines understanding image context
Meeting WCAG 2.1 accessibility guidelines
Improving overall site quality and compliance

This tool provides a clear summary, detailed image-level analysis, and actionable recommendations—all in seconds.

Key Features

Analyze images from any live webpage URL
Paste raw HTML for offline or local testing
Detect missing alt attributes
Identify decorative images using empty alt (alt="")
Evaluate alt text length and quality
Calculate an overall Accessibility Score
Paginated, searchable image reports
Copy, save, share, or embed results
No login required, completely free

How It Works

Step 1: Enter Website URL or HTML

Provide the full webpage URL you want to analyze, or paste HTML manually for custom or local code.

Step 2: Run Alt Tag Analysis

Click “Check Alt Tags”. The tool scans all <img> elements on the page.

Step 3: Review Accessibility Score

Get a clear score (Poor → Excellent) based on alt tag coverage and best practices.

Step 4: Inspect Detailed Results

View categorized lists of:

Images with proper alt text
Images missing alt attributes
Decorative images with empty alt

Step 5: Apply Recommendations

Use insights to improve accessibility, SEO, and compliance instantly.

Accessibility Score Explained

Your accessibility score reflects how well your images follow accessibility standards:

Excellent – All images are properly handled
Good – Minor improvements recommended
Fair – Noticeable accessibility gaps
Poor – Significant issues impacting users

The score considers:

Alt text presence
Appropriate use of empty alt for decorative images
Alt text quality and length

Output Breakdown

Summary

Total images found
Count of images with alt text
Count of missing alt attributes
Decorative images detected
Percentage distribution with visual indicators

Image Issue Table

Image source URL
Detected issue (missing, empty, or valid alt)
Preview support
Paginated navigation for large pages

Alt Text Quality Report

Alt text value
Character length
Quality assessment
Duplicate detection visibility

Why Alt Text Matters

Accessibility: Screen readers rely on alt text to describe images
SEO: Search engines use alt text to understand image context
Compliance: Required under WCAG, ADA, and global accessibility laws
User Experience: Provides context when images fail to load

Ignoring alt text can negatively impact rankings, usability, and legal compliance.

Best Practices for Alt Text

Be descriptive but concise
Avoid keyword stuffing
Skip phrases like “image of” or “picture of”
Use empty alt (alt="") only for decorative images
Reflect the image’s purpose, not just appearance

Who Should Use This Tool

Web developers
SEO professionals
UX / accessibility auditors
Content writers
WordPress site owners
Digital agencies
Compliance teams

Use Cases

Pre-launch accessibility audits
SEO optimization checks
WCAG compliance validation
Website redesign reviews
Client reporting and documentation

Data Privacy & Security

No data is stored permanently
URLs are analyzed in real time
HTML input stays within the session
No tracking, no account required