Adform banner specs: HTML5 and weights
What Adform asks of HTML5 banners: the package, manifest.json, the DHTML library and clickTAG, weight limits for desktop and mobile, animation length and its standard sizes, from Adform’s own help center.
Checked on Oct 16, 2026 against the platform’s own pages. The sources are listed at the end of the guide.
HTML5 banners
| Package | A ZIP with manifest.json and the main HTML file at its root; at least two files |
|---|---|
| manifest.json | Defines the name, description, size, events, click tags and source |
| DHTML library | Required in the head of every web banner |
| Click tag | Read with dhtml.getVar; every clickTAG is declared in the manifest; names are case-sensitive |
| Weight | Measured with the files unpacked |
| In-app banners | Use MRAID instead of the DHTML library |
Weights and animation
| Desktop standard ads | 300 KB |
|---|---|
| Mobile standard ads | 5 KB initial load, 200 KB at most |
| Rich media | 300 KB recommended |
| Animation | 30 seconds at most, then it must stop |
Standard sizes
| Most popular | 300 × 250, 336 × 280, 728 × 90, 300 × 600, 320 × 100 |
|---|---|
| Desktop | 300 × 250, 970 × 250, 728 × 90, 300 × 600, 160 × 600 |
| Smartphone | 300 × 250, 320 × 50, 320 × 480, 250 × 250 |
| Tablet | 728 × 90, 300 × 250, 160 × 600, 300 × 600 |
How to upload
- 1In Adform Studio, click NEW, then Upload Banner, and choose the banner’s ZIP file.
- 2If Adform cannot read the banner’s details, choose its category and format, enter its size and click Upload.
- 3To send it to a campaign, open the banner, use the upload icon and choose Upload to Ad Server, pick the advertiser and the campaign, and click Upload.
Good to know
- Adform weighs the banner unpacked, so a ZIP under 300 KB can still be too heavy. Sizewright checks the unpacked weight.
- Adform’s mobile guidelines set a 5 KB initial load. Sizewright’s HTML5 packages load all at once, so on mobile placements that hold to it, use the still image.
- Adform’s ad quality policies ask for animation of 30 seconds or less, GIFs at 5 frames per second or less, a visible border when the ad’s background is white, and no shaking or flickering.
What Sizewright delivers for Adform
| Package | Delivers |
|---|---|
| AdformSpecs checked | JPG or PNG, up to 150 KBHTML5 ZIP with clickTag, up to 300 KB unpacked, backup image |
Sizes
- 300 × 250Medium Rectangle
- 336 × 280Large Rectangle
- 250 × 250Square
- 200 × 200Small Square
- 728 × 90Leaderboard
- 970 × 90Large Leaderboard
- 970 × 250Billboard
- 468 × 60Banner
- 320 × 50Mobile Leaderboard
- 300 × 50Mobile Banner
- 320 × 100Large Mobile Banner
- 300 × 600Half Page
- 160 × 600Wide Skyscraper
- 120 × 600Skyscraper
- 300 × 1050Portrait
- 320 × 480Mobile Interstitial
- 800 × 250Billboard (OVK)
Questions about Adform
Does Adform weigh the ZIP or the files?
The files, unpacked. The 300 KB desktop limit applies to the unpacked banner, so a smaller ZIP can still be over it; Sizewright checks the unpacked weight before the download is offered.
Where does the clickTAG come from?
From Adform when the ad serves: the banner reads it with dhtml.getVar, and every clickTAG is declared in manifest.json. Sizewright’s Adform package does both.
Sources
- adformhelp.com/hc/en-us/articles/9738596324881-Requirements-for-HTML5-Banner-Files
- adformhelp.com/hc/en-us/articles/10893850708241-Code-HTML5-Banners
- adformhelp.com/hc/en-us/articles/9738579515025-Guidelines-for-Display-Ads
- adformhelp.com/hc/en-us/articles/9739157535121-Guidelines-for-Mobile-Ads
- adformhelp.com/hc/en-us/articles/10480682654097
- adformhelp.com/hc/en-us/articles/10480682575249
- adformhelp.com/hc/en-us/articles/9739167460625
Checked Oct 16, 2026
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