The specifications are not rigid requirements imposed by AdLib, rather, they are an aggregation of requirements from our supply sources. Adhering to them will ensure both maximum exposure for your advertisements as well as a smooth user experience for your audience.

Accepted 3rd Party Ad Tag Formats

Display/Mobile: Javascript, Iframe and Standard (a href/img src)
Video: VAST 1.0, VAST 2.0, VAST 3.0, VPAID 1.0 and 2.0, VAST URL or VAST Source XML, VAST with VPAID 

Accepted File Formats

Display & Mobile Assets
500kb Max

All animations must stop after 15 seconds

flv, .mp4, .avi, wmv, .mpeg1/2, .webm, .mov,
1GB Max

.wav or .ogg
1GB Max

Accepted Ad Dimensions

Display Ad Dimensions

300x250, 728x90, 160x600, 300x600, 970x250, 336x280, 468x60, 120x600, 180x150, 250x250, 234x60, 970x90, 200x200 300x1050

Mobile Ad Dimensions

320x480, 320x50, 728x90, 300x250, 360x640, 300x50, 216x36, 120x20, 168x28, 480x320, 768x1024, 120x240

Video Ad Dimensions

1920x1080:700, 1920x800:700, 1280x720:400, 854x480:400,1024x768:400, 640x380:100, 640x480:100, 640x360:100,480x360:100, 320x240:100, 300x250:100

Audio Ad Companion Banner Dimensions

300x250, 728x90, 300x50, 320x50, 500x500, 540x640, 640x640

HTML5 Assets

AdLib Ad Server HTML5 Asset Package:

This zip file must contain a root HTML document within the root directory:

  • The HTML5 Asset Package file name and the names of any files (HTML, JavaScript, CSS or Image) within the Asset Package must not contain any blank spaces or non-English characters.

  • As a best practice, it is recommended to have a single HTML document named index.html in the root directory of the zip file.

  • If the zip file has a single HTML document in the root directory, that HTML document will be used as the root document for the Creative.

  • If the zip file has multiple HTML documents in the root directory, and one of them is named index.html, the index.html file will be used as the root HTML document.

  • If the zip file has multiple HTML documents in the root directory, and none of them are named index.html, the first HTML document detected by AdLib Ad Server during upload will be used as the root HTML document.

  • The root HTML document can be infinite characters in length (including spaces and comments).

  • The root HTML document must have all tracked URLs, including URLs set via a JavaScript, prepended with AdLib's unencoded click tracker.

  • The root HTML document must not have any tags.

  • The zip file can also contain any of the following documents: CSS, JavaScript, Image, Flash, Web Fonts and additional HTML documents. 

  • The file extensions supported by AdLib Ad Server are: .SWF (Flash), .GIF, .JPG, .JPEG, .TIF, .TIFF, .PNG, .CSS, .HTML, .HTM, .JS, .WOFF, .WOFF2, .SVG.

  • All resources referenced in the root HTML document must be referenced via relative links to files included in the HTML5 Asset Package. 

  • External images not included in the HTML5 Asset Package cannot be referenced from the root HTML document.

  • The assets included in the Asset Package must not use local storage or session storage.

  • The HTML5 Asset Package zip file cannot contain zip files within it.

  • If the HTML5 Asset Package contains Flash (.SWF) files, the ad will not serve in Chrome and on exchanges which do not support Flash (e.g. AdX).

  • AdLib Ad Server does not currently support video files within the HTML5 Asset Package.

  • AdLib Ad Server HTML5 does not currently support expandable or MRAID.

HTML5 Backup Image:

  • Each AdLib Ad Server HTML5 Creative must have a single unique Backup Asset which is an Image Asset provided during upload.

  • This Backup Image will be uploaded outside of the HTML5 Asset Package zip file.

  • This Backup Image must have the same name as the HTML5 Asset Package.

  • The Backup Image will be served when the Creative is shown to users whose browser / environment has JavaScript disabled.

  • Since AdLib Ad Server does not currently support responsive / resizable ads, the dimensions of the Backup Image selected will be used as the dimensions of the HTML5 Creative.

Uploading Files into AdLib

Prepare Backup Image and Root File asset package for upload:

The Root File asset package should include the following components:

Attaching a Click Tracker to Your HTML5 Ad

For AdLib Ad Server HTML5 Creative, the AdLib click tracker will need to be manually added to each HTML5 Creative’s root HTML document (for ads generated from most builders, this document is named index.html in the root directory of the HTML5 Asset Package zip file). All click through URLs must be located in the root HTML document and the AdLib click tracker must be prepended to all click through URLs to ensure tracking of clicks during ad serving.

Below are guidelines on how the AdLib click tracker can be added into the document for a sample set of scenarios. Please note that the guidelines do not cover all possible scenarios. It is up to you to ensure that the click tracker is included in the HTML document.

Step 1: Open The Root HTML Document For Your Creative

  • Open the root HTML document for your HTML5 ad. In most cases, this is the document named ‘index.html’ in the HTML5 Asset Package.

Step 2: Add AdLib Click Tracker To All Clickable Elements

Scenario A: Click Implementation via JavaScript Variables

HTML5 ads may implement click through via JavaScript variables.

In such cases, the click through is often implemented via a variable named ‘clickTag’ (although different may have different names for the variable) enclosed within script tags as shown below:

<script type="text/javascript">
<--Javascript or HTML Markup-->
var clickTag = ""; </script>

In this case, AdLib's unencoded click tracker will be prepended to the click through url ( as shown below:

<script type="text/javascript">
<--Javascript Markup-->
var clickTag = "[UNENCODED_CLICK_REDIRECT]"; </script>

Please note that using the following method to implement click through in the body of the HTML document in Firefox will result in a successful redirect to the click through url in a new tab.

However, the ad served in the original tab will disappear and be replaced by the text “[object Window]”“[UNENCODED_CLICK_REDIRECT]”)

This is because Firefox expects a value to be returned for the JavaScript function. If it does not receive a value, it replaces the HTML body with “[object Window]”. This can be fixed by forcing the expression to return a value by modifying the click through expression to:


Scenario B: Click Implementation via HTML Attributes

HTML5 ads may implement click through via HTML attributes. In such cases, the click through is often implemented via the ‘href’ attribute which is enclosed in anchor <a> tags. as shown below:

<a href="">  <--HTML Markup-->  </a>

In this case, AdLib’s unencoded click tracker will be prepended to the click through url ( as shown below:

<a href="[UNENCODED_CLICK_REDIRECT]"> <--HTML Markup--> </a>

Please note that using the href attribute to implement click through will result in the click through breaking when all of the following conditions are met:

  • The ad is served on a device with iOS version 9 or higher installed

  • The ad's click through redirects to the iOS App Store

To avoid broken redirects when the above conditions are met, please use an alternative method for implementation of click through.

Step 3: Save and Test

  • Save the root HTML document.

  • Open the document in a web browser and try clicking on the ad.

  • In your test, the click will lead you to an error page which has the local file path followed by the AdLib Click Tracker and your click through URL in the browser address bar as shown below:

  • file:///LocalFilePath/[UNENCODED_CLICK_REDIRECT]

  • This is the expected result and a sign that your ad will click through as expected. This can be confirmed by testing the click through in AdLib preview.

  • During ad serving, the click tracker will be expanded to ensure that AdLib tracks all clicks for impressions served and the click tracker redirects to the valid, desired click through URL.

Step 4: Zip Ad Contents

  • Select all of the files / folders of the ad and compress the contents into a zip file.

  • You are now ready to upload your HTML5 ad into AdLib!

Additional Helpful Resources:

IAB HTML5 Resources:

IAB MRAID Resources:

IAB VPAID Resources:

IAB Creative Specifications:
     **These are not always the same as AdLib specifications as we normalize against our supply source requirements.**

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