Standard IAB clickTag for DSPs

Most DSPs that accept direct HTML5 creative uploads use the standard IAB var clickTag format. This guide covers the implementation for The Trade Desk, Amazon DSP, Yahoo DSP, StackAdapt, and Mediasmart: five DSPs that share the same clickTag pattern with minor differences in click macros and weight limits.

How it works

All five DSPs use the IAB standard var clickTag pattern. You declare a global variable named clickTag with a fallback URL, and each DSP replaces it with the actual destination URL at serve time. The same creative ZIP can be uploaded to any of these platforms without modification.

This is the same format used by CM360 and Equativ. If you've already built a creative for either of those platforms, it will work on these DSPs as well.

Standard implementation

Here is the universal pattern that works across all five DSPs:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="ad.size" content="width=300,height=250">
  <script>
    var clickTag = "https://example.com";
  </script>
</head>
<body>
  <div id="banner" onclick="window.open(clickTag, '_blank')">
    <!-- ad content -->
  </div>
</body>
</html>

Key points: var clickTag declared globally, meta ad.size in the head, and a click handler using window.open(clickTag).

Platform-specific details

While the clickTag format is identical, each DSP has its own click macro and weight limits. During development, use a placeholder URL; the DSP replaces it at serve time.

The Trade Desk

Click macro: %%TTD_CLK%% or %%TTD_CLK_ESC%%

Max ZIP size: 200 KB

Backup image: required, max 150 KB

Animation: max 30 seconds, 15 fps recommended

Notes: all assets must be self-contained in the ZIP, no external resource loading. Stricter file size limits than most ad servers.

Amazon DSP

Click macro: %%CLICK_URL%%

Max ZIP size: 200 KB

Backup image: required

Animation: max 15 seconds on Amazon-owned properties

Notes: distinct from Amazon Ad Server (Sizmek). Amazon DSP is for buying programmatic inventory; the ad server is for serving and tracking. Ads on Amazon-owned properties (Amazon.com, IMDb, Twitch) may have additional creative guidelines.

Yahoo DSP

Click macro: %%CLICK_URL%%

Max ZIP size: IAB standard (200 KB recommended)

Backup image: required

Notes: follows standard IAB specifications for HTML5 display creatives.

StackAdapt

Click macro: replaced automatically at serve time

Max ZIP size: 200 KB recommended

Backup image: required

Notes: popular among mid-market agencies. Self-serve platform where advertisers upload creatives directly. Standard IAB clickTag creatives work without modification.

Mediasmart

Click macro: replaced automatically at serve time

Max ZIP size: IAB standard

Backup image: required

Notes: follows standard IAB specifications. Standard clickTag creatives work without modification.

Key differences from ad servers

When you upload a creative directly to a DSP (instead of trafficking it through a third-party ad server like CM360 or Innovid), there are a few things to keep in mind:

No third-party tracking

Creatives uploaded directly to a DSP bypass third-party ad server tracking. Reporting is limited to the DSP's own analytics. If you need cross-platform reporting, serve the creative through a third-party ad server instead.

Stricter file size limits

Most DSPs enforce a 200 KB ZIP limit, compared to ad servers like CM360 which have no hard ZIP limit. Make sure your creative is optimised for size before uploading to a DSP.

Self-contained assets

DSPs typically require all assets to be bundled in the ZIP with no external resource loading. This is stricter than some ad servers which allow polite loading of external assets.

How Adloom helps

Multi-platform compatibility

Upload your creative once and Adloom shows you which DSPs it's compatible with. A standard IAB clickTag creative works on all five DSPs listed here, plus CM360 and Equativ.

Weight optimisation

Adloom checks your creative's weight against each platform's limits. If your ZIP exceeds the 200 KB DSP limit, the "Fix all" button can compress images and minify code to bring it under the threshold.

One-click auto-fix

If your creative is missing the clickTag variable, Adloom can inject it automatically. The same fix makes your creative compatible with all standard IAB platforms in one click.

Next steps