How to Test HTML5 Creative Zips with AdMeIn

A Guide on Testing HTML5 Creative ZIPs with AdMeIn Creative ZIP Validator

Upload and validate complete HTML5 ad creative packages to ensure they meet industry standards and will run correctly across ad platforms.

Sign in to your AdMeIn account

Navigate to the Creative ZIP Validator tool
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Upload your creative ZIP file

Click the upload area or drag and drop your HTML5 creative ZIP file
The ZIP should contain all assets needed for your ad: HTML, CSS, JavaScript, images, and fonts
Maximum file size and requirements vary by platform, but AdMeIn will validate against common standards

View your validation results

Once uploaded, AdMeIn automatically analyzes your ZIP contents
You'll receive a comprehensive report covering file structure, asset compliance, and technical validation
Interactive preview shows how your creative will render in real-world scenarios

On a successful validation

Once your creative ZIP is successfully analyzed, you'll see:

File Structure Analysis: Complete inventory of all files and folders in your ZIP
Asset Validation: Checks for required files (index.html), proper file types, and naming conventions
Size Compliance: Total file size and individual asset sizes validated against industry standards
Technical Checks: HTML/CSS/JavaScript syntax validation and error detection
Security Validation: HTTPS requirements, external resource checks, and SSL compliance
Live Preview: Real-time rendering of your creative showing exactly how it will display
Platform Compatibility: Validation against Google Ad Manager, DV360, and other major ad server requirements

Understanding HTML5 Creative ZIP Structure

We have an in-depth guide on what HTML5 ads are and how they work end-to-end.
Check out our What Are HTML5 Ads? article here if you want to learn more about the format and how to create them.

A properly structured HTML5 creative ZIP contains all assets needed for your ad to run independently.

The AdMeIn Creative ZIP Validator expects the following structure:

Required Files

index.html: The entry point of your creative (must be at the root level)
Backup image: A static fallback image (e.g., backup_300x250.jpg)

Common Files

CSS files: Stylesheets for layout and animation (main.css, styles.css)
JavaScript files: Creative logic and interactivity (main.js, app.js)
Images: PNG, JPG, WebP, SVG, or GIF assets
Fonts: WOFF2, WOFF, or TTF font files (if not using system fonts)
Assets folder: Organized directory for images and other resources

Example Structure

creative-300x250.zip
├── index.html
├── main.css
├── main.js
├── backup_300x250.jpg
└── assets/
    ├── logo.svg
    ├── background.jpg
    └── animation.json

What Gets Analyzed

The Creative ZIP Validator performs comprehensive validation including:

File Structure Validation

Root index.html: Confirms index.html exists at the ZIP root
File Organization: Checks folder structure and naming conventions
Required Assets: Validates presence of backup image and essential files
Prohibited Files: Flags development files, source maps, or hidden system files
Path References: Ensures all referenced assets exist in the ZIP

Size and Performance

Total ZIP Size: Validates against platform limits (typically 150-200KB for standard, 300KB+ for rich media)
Individual File Sizes: Checks for oversized images or scripts
Compression: Verifies images are properly optimized
Resource Count: Ensures reasonable number of HTTP requests

Technical Compliance

HTML Validation: Checks markup syntax and structure
CSS Validation: Validates stylesheets and animation code
JavaScript Validation: Detects syntax errors and console warnings
Click Handling: Verifies clickTag implementation
HTTPS Requirements: Ensures all external resources use secure URLs
Ad Server Compatibility: Checks for platform-specific requirements

Creative Standards

Dimensions: Validates creative matches declared size (300x250, 728x90, etc.)
Animation Timing: Checks animation duration and looping behavior
File Types: Validates allowed formats and flags prohibited types
Backup Image: Confirms backup image matches creative dimensions
Polite Loading: Validates asset loading strategies

IAB and Platform Standards

AdMeIn validates your creative against:

IAB Display Advertising Guidelines

Standard banner sizes (300x250, 728x90, 160x600, etc.)
Initial load file size limits (150KB standard, 200KB max)
Animation duration and looping restrictions
SSL/HTTPS requirements

Platform-Specific Requirements

Google Ad Manager (GAM): Size limits, clickTag format, meta tags
DV360: Additional security checks and asset restrictions
Studio: Backup image requirements and specific API usage
Sizmek/Flashtalking: Platform-specific click handling

Best Practices for Creative ZIPs

Keep It Simple: Include only necessary files—no development tools or source files
Optimize Everything: Compress images, minify code, use efficient formats (WebP, SVG)
Test Locally First: Open index.html in a browser before zipping
Use Relative Paths: All asset references should be relative, not absolute URLs
Include Backup Image: Always provide a static fallback matching your creative size
Follow Naming Conventions: Use lowercase, hyphens, avoid spaces
Implement clickTag: Use standard clickTag variable for universal compatibility
Stay Under Budget: Target 100-150KB for standard banners
Test Polite Loading: Ensure heavy assets load after page ready
Remove Comments: Strip out development comments and console logs

Common Issues and Solutions

ZIP Won't Upload

Check file size: Ensure ZIP isn't too large for your account tier
Verify format: Must be a valid ZIP archive (not RAR, 7z, or other formats)
Login status: Confirm you're logged into your AdMeIn account

Missing index.html

Root level required: index.html must be at the ZIP root, not in a subfolder
Correct filename: Must be exactly "index.html" (lowercase, no spaces)
Not in nested folder: Don't zip a folder containing the files—zip the files directly

Oversized Creative

Optimize images: Use WebP format, compress JPGs, reduce dimensions to exact size needed
Minify code: Remove whitespace and comments from CSS/JS
Inline small assets: For tiny images or SVGs, consider inlining in HTML
Remove unused files: Delete any assets not actually used by the creative
Self-host fonts: If using web fonts, subset them to include only needed characters

Broken Asset References

Use relative paths: assets/logo.svg not /assets/logo.svg or https://...
Check case sensitivity: Logo.svg ≠ logo.svg on some servers
Verify files exist: All referenced assets must be present in the ZIP
Test locally: Open the unzipped files in a browser to catch broken links

clickTag Not Working

Use standard format: window.clickTag = window.clickTag || 'https://default.com';
Don't hardcode URLs: Let ad server override the clickTag variable
Test click handler: Ensure click events properly use the clickTag value
Check target: Use window.open(clickTag, '_blank') or platform-specific APIs

External Resources Detected

Self-host everything: Include all fonts, libraries, and assets in the ZIP
No CDN calls: Don't load jQuery, GSAP, or fonts from external CDNs
HTTPS only: If external calls are required and allowed, ensure they're HTTPS
Check third-party tags: Remove tracking pixels or tags meant for the ad server layer

After Validation

Once your creative passes validation:

Download the Report: Save validation results for your records and QA documentation
Test in Ad Server: Upload to your target platform (GAM, DV360, etc.) for final testing
Preview in Context: Use the ad server's preview tools to see the creative on real sites
Cross-Browser Check: Test in Chrome, Safari, Firefox, and Edge
Mobile Testing: Preview on actual mobile devices if targeting mobile placements
Monitor Performance: Track loading speed and user interactions after going live

Additional Resources

Learn more about creating high-quality HTML5 ads

What Are HTML5 Ads and How to Create Them - Comprehensive guide to HTML5 ad development
How to Test HTML5 Ad Tags - Testing individual ad tags vs complete creative packages
Ad Tag Example Gallery - View real-world examples and best practices
HTML5 Creative Banner Generator - Build simple HTML5 banners with our generator tool

Need Help?

If you encounter issues or have questions:

Check validation errors: Review the detailed error messages in your validation report
Review our examples: Compare your structure to working examples in our gallery
Contact support: Get in touch with specific error messages or ZIP files for assistance
Platform documentation: Consult your target ad server's HTML5 creative specifications