Adform HTML5 banner specs

European ad server and demand-side platform, strongest in the Nordics and DACH. Uniquely among the major platforms it requires a manifest.json alongside the creative, which declares the banner's dimensions, custom events and every click destination it supports.

Sourced from Adform documentation · 20 September 2026Foldwrap exports to Adform

Also known as Adform DSP, Adform FLOW.

Check a ZIP against Adform Export a bundle for Adform

Adform banner requirements

Category	Ad server
Regions	EU, NORDICS, DACH, UK
Maximum ZIP size	300 KB unzipped
Entry file	index.html
ZIP structure	Entry file must sit at the ZIP root
Ad size meta tag	Optional
External assets	External assets allowed
External fonts	Allowed
CDN libraries	Allowed
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
Click destinations declared	In a manifest file beside the creative
Maximum animation length	30s
Animation must stop	Yes, once the limit is reached

Official requirements Also from Adform: Check for SSL Compliance, Code HTML5 Banners.

Adform clickTag code

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

Adform clickTag

var clickTAG = dhtml.getVar('clickTAG', "https://www.example.com/landing");

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

Required scripts

Adform requires its own library in the document. Foldwrap adds it automatically on export.

s1.adform.net/banners/scripts/rmb/Adform.DHTML.js

<script>
    document.write('<script src="' + (window.API_URL || 'https://s1.adform.net/banners/scripts/rmb/Adform.DHTML.js?bv=' + Math.random()) + '"><\/script>');
</script>

Must load before the clickTAG declaration, which calls dhtml.getVar() on it.

Why Adform rejects a banner

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

errorAnimation runs longer than allowedShorten the timeline or reduce the loop count.
errorClick is not wired for this platformDeclare clickTAG in the creative and open it on click.
errorEntry HTML is not at the ZIP rootRe-zip the contents, not the containing folder.
errorExceeds size limitCompress images, subset fonts to the glyphs actually used, and drop unused assets.
errorMissing required fileRe-export for Adform - Foldwrap generates this file automatically.
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.
errorRequired platform script missingRe-export for Adform - Foldwrap adds this script automatically.
errorRequired script must load first

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

Standard Display Ad (Desktop) Specifications. File Types: .jpeg (.jpg), .png, .gif or HTML5-based or 3rd-party banners. Maximum Size: 300 KB.
adformhelp.com · retrieved 20 September 2026
Standard Display Ad (Mobile) Specifications. Max Size: Initial load: 5KB, Max. 200KB. Applies to both smartphones and tablets, mobile web and in-app.
adformhelp.com · retrieved 20 September 2026
The components used to create the banner also must follow SSL requirements. If a banner component has a link to an external resource, it must lead to an SSL-compliant page.
adformhelp.com · retrieved 20 September 2026
SSL-compliant URLs begin with https:// or // instead of http://. // is used in protocol-relative URLs that don't have either HTTPS or HTTP at the beginning.
adformhelp.com · retrieved 20 September 2026
Animation: Maximum 30 secs (must stop after 30 sec.)
adformhelp.com · retrieved 20 September 2026
The manifest.json file defines banner parameters (such as name, description, dimensions, events, clicktags, and source).
adformhelp.com · retrieved 18 September 2026
A metadata file called manifest.json: The manifest.json file defines banner parameters (such as name, description, dimensions, events, clicktags, and source).
adformhelp.com · retrieved 18 September 2026
A manifest.json file and a defined main HTML source should be located in the root of the .zip file. Otherwise, Adform can't extract the zipped content correctly.
adformhelp.com · retrieved 18 September 2026
Adform measures the total banner 'weight' when the file is unzipped.
adformhelp.com · retrieved 18 September 2026
Every HTML5 banner uploaded to Adform must have Adform DHTML library inserted within the <head> tags of the HTML file.
adformhelp.com · retrieved 18 September 2026
JavaScript sources: such as jQuery, GreenSock animation libraries and components, and so forth if they are used in a banner. You can include libraries as local assets or as external sources.
adformhelp.com · retrieved 18 September 2026
Other assets: such as images, fonts, XML files, and so forth from local directories or from external paths.
adformhelp.com · retrieved 18 September 2026
Adform recommends hosting all assets and resources on Adform's servers, which both support SSL and ensure load-balanced and geographically distributed delivery of content.
adformhelp.com · retrieved 20 September 2026
const clickTAGvalue = dhtml.getVar('clickTAG', 'https://example.com');
adformhelp.com · retrieved 18 September 2026
If your banner has multiple clickTAG instances, you must define all of them in a clicktags section in a manifest.json file.
adformhelp.com · retrieved 18 September 2026

Frequently asked

What is the maximum file size for a Adform HTML5 banner?

Adform accepts an HTML5 package up to 300 KB 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 Adform?

Declare clickTAG in the creative. Adform replaces the value when the ad is trafficked, so exporting with an empty destination is normal and correct.

Can a Adform banner have more than one clickable link?

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

Can a Adform banner load fonts or scripts from a CDN?

Adform permits assets and libraries loaded from external hosts, so a font or a CDN-hosted library in the markup is acceptable.

Other platforms

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