1. Preview an HTML5 ad by uploading an HTML5 zip file
2. View a live ad preview, images of each frame, and a video of the ad
3. View network timelines, load times, file sizes, and more to ensure ads are compliant
4. Share with clients and get feedback

HTML5 ads are similar to HTML ad tags, but they come packaged as a zip file that includes all of the assets needed for the ad. Unlike VAST video tags, HTML5 ads can include interactive elements and animations.
They are often visually appealing, highly animated, and interactive ads. HTML5 ads can also range in size to support desktop and mobile web.

Just like third-party HTML ad tags, HTML5 ads often have poor load performance because they contain fetch multiple files from different places, so it's crucial to test your HTML5 ads and optimize their files.

HTML5 ad file size limits vary by platform and ad network. Industry-standard limits include:

• Google Ad Manager & Campaign Manager 360: 150KB initial load, up to 2.2MB total with polite loading
• Google Display & Video 360 (DV360): 150KB initial load recommended, though some sources mention up to 10MB for images
• Facebook/Meta: Varies by format - check current Meta advertising specifications
• Most Ad Exchanges: 150KB initial load is the widely accepted standard

Important: While some platforms may technically accept larger files, the 150KB initial load limit is considered best practice across the programmatic advertising industry to ensure compatibility and optimal performance.

Our HTML5 ad validator helps you check if your ads meet these file size requirements and identifies which files are contributing to larger sizes.

HTML5 ads are supported by all modern browsers including:

• Chrome 60+ (desktop and mobile)
• Safari 12+ (desktop and mobile)
• Firefox 70+ (desktop and mobile)
• Edge 79+ (desktop and mobile)
• Samsung Internet 10+
• Opera 50+

However, specific HTML5 features like WebGL, advanced animations, or audio may have different support levels. Our validator tests your ads across multiple browser environments to ensure compatibility.

To optimize HTML5 ad loading performance:

1. Compress images: Use WebP format when possible, optimize PNG/JPG files
2. Minimize CSS and JavaScript: Remove unused code and compress files
3. Reduce HTTP requests: Combine files where possible, use CSS sprites
4. Optimize fonts: Use web fonts efficiently or system fonts
5. Test file sizes: Stay within platform limits (typically 150KB initial load)

Our network timeline analysis shows exactly which files are slowing down your ad load times, helping you identify optimization opportunities.

We support all standard HTML5 ad formats including:

• Display formats: Banner, leaderboard, skyscraper, rectangle sizes
• Rich media: Expandable, floating, interstitial ads
• Video: In-banner video, outstream video ads
• Interactive: Playable ads, gamified experiences
• Responsive: Fluid, flexible sizing for mobile and desktop

Upload your HTML5 zip file and our validator will automatically detect the format and test it against industry standards.

To ensure CM360 acceptance, your HTML5 ads must meet these requirements:

1. File structure: Include index.html as main file, all assets in zip
2. Size limits: 150KB initial load, 2.2MB total compressed
3. Click tracking: Use Enabler.exitOverride() for clickthrough URLs
4. Backup image: Include fallback GIF/PNG for unsupported browsers
5. No external calls: All assets must be included in zip file

Our validator specifically tests for CM360 compliance and highlights any issues that would prevent acceptance.