Google Ad Manager HTML5 banner specs

Google's publisher ad server. Agencies upload HTML5 packages here for direct-sold and programmatic-guaranteed placements.

Sourced from Google Ad Manager documentation · 21 September 2026Foldwrap exports to Google Ad Manager

Also known as GAM, DFP, DoubleClick for Publishers.

Check a ZIP against Google Ad Manager Export a bundle for Google Ad Manager

Google Ad Manager banner requirements

Category	SSP
Regions	GLOBAL
Maximum ZIP size	1 MB zipped or unzipped
Entry file	index.html
Ad size meta tag	Required — width={w},height={h}
External assets	External assets discouraged
Secure references	Every external reference must be served over HTTPS
Click method	clickTag variable
Click variable	clickTag
Click URL at export	Left empty — the platform sets it when the ad is trafficked
Multiple click destinations	Supported

Official requirements Also from Google Ad Manager: Traffic HTML5 creatives.

Google Ad Manager clickTag code

This is the click declaration Foldwrap writes into an HTML5 export for Google Ad Manager, with a placeholder destination. Copy it into your own creative if you are hand-building the banner.

Google Ad Manager clickTag

var clickTag = "https://www.example.com/landing";

Google Ad Manager sets the destination at trafficking time, so an empty value in the exported file is correct and expected.

Why Google Ad Manager rejects a banner

These are the rules Foldwrap checks a package against before it is delivered to Google Ad Manager. Each is derived from the requirements above, so a constraint Google Ad Manager does not state is not checked and is not listed.

errorad.size meta tag missingAdd <meta name="ad.size" content="width=300,height=250"> to the head.
errorClick is not wired for this platformDeclare clickTag in the creative and open it on click.
errorExceeds size limitCompress images, subset fonts to the glyphs actually used, and drop unused assets.
errorNo entry HTMLAdd index.html at the ZIP root.
errorReferenced asset is not in the packageRe-export the creative so every referenced asset is bundled.
warningad.size does not match the creativeRe-export so the declared size matches the canvas.
warningExternal reference the platform discouragesBundle the asset inside the ZIP if you can; Google Ad Manager publishes no list of hosts it accepts.
warningNested archive detectedUnpack the inner archive and re-zip a single creative.

Foldwrap runs these checks on every package it exports for Google Ad Manager, and names the creative and the constraint when one fails.

Sources

Every figure above, with the document it came from and the date we read it.

An HTML5 bundle or the total size of extracted files cannot exceed 1MB.
support.google.com · retrieved 18 September 2026
An HTML5 bundle or the total size of extracted files cannot exceed 1MB.
support.google.com · retrieved 18 September 2026
Insert click tags in the <head> of your HTML documents.
support.google.com · retrieved 18 September 2026
Click tags allow the ad server to track ad clicks, and they define click-through URLs for each exit on your HTML5 creative.
support.google.com · retrieved 21 September 2026
HTML5 creatives must be SSL compatible to serve on HTTPS sites.
support.google.com · retrieved 20 September 2026
Avoid external hosting of essential creative components unless explicitly supported and allowlisted by Ad Manager.
support.google.com · retrieved 20 September 2026

Frequently asked

What is the maximum file size for a Google Ad Manager HTML5 banner?

Google Ad Manager accepts an HTML5 package up to 1 MB zipped or unzipped. Note what the cap measures: a bundle can compress under the limit and still be refused if the figure is taken unzipped.

How do I set the clickTag for Google Ad Manager?

Declare clickTag in the creative. Google Ad Manager replaces the value when the ad is trafficked, so exporting with an empty destination is normal and correct.

Can a Google Ad Manager banner have more than one clickable link?

Yes. Google Ad Manager supports multiple named click destinations, so individual elements in the banner can point at different pages.

Can a Google Ad Manager banner load fonts or scripts from a CDN?

Google Ad Manager asks you to avoid loading essential parts of the creative from an external host, but publishes no list of hosts it accepts and no outright ban. Bundle what you can inside the ZIP; treat anything left outside as a risk you are choosing.

Other platforms

Compare every platform side by side, or produce a Google Ad Manager-ready bundle from an approved Figma design with Foldwrap.