StackAdapt HTML5 banner specs

Canadian-founded demand-side platform buying native, display, video, CTV, audio and DOOH inventory. Accepts HTML5 display creatives alongside static JPG/PNG/GIF, and caps display packages at 750 KB zipped.

Limits unverified — this page shows only what we can citeFoldwrap exports to StackAdapt

Also known as Stack Adapt.

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StackAdapt banner requirements

CategoryDSP
RegionsGLOBAL, US, CA
Maximum ZIP size750 KB zipped
Entry fileindex.html
Click methodclickTag variable
Click variableclickTag
Click URL at exportLeft empty — the platform sets it when the ad is trafficked
Multiple click destinationsOne click area per banner

Fields StackAdapt does not publish, or that we have not yet read from a primary document, are left off this table rather than filled with a plausible number.

Official requirements Also from StackAdapt: Display advertising specs (public FAQ), StackAdapt Ad Specifications (Academy), Available Creative Formats (Help Center).

StackAdapt clickTag code

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

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

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

Why StackAdapt rejects a banner

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

  • 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.
  • warningElement destinations flatten hereKeep a target that supports element destinations in the set, or set a default click URL that suits every element.

Foldwrap runs these checks on every package it exports for StackAdapt, 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.

Frequently asked

What is the maximum file size for a StackAdapt HTML5 banner?
StackAdapt accepts an HTML5 package up to 750 KB zipped. 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 StackAdapt?
Declare clickTag in the creative. StackAdapt replaces the value when the ad is trafficked, so exporting with an empty destination is normal and correct.
Can a StackAdapt banner have more than one clickable link?
No. StackAdapt takes a single click destination for the whole banner, so every click goes to the same page regardless of which element was clicked.

Other platforms

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