Banner ad sizes and modern image formats.

The right banner size is the one the placement uses.

Standard dimensions make creative production easier, but they should follow the site’s layout rather than dictate it. A publisher should create a placement with the exact width and height available on the page. The buyer should then export artwork at those exact dimensions.

Do not require multiple sizes by default. A campaign using one 200×200 sidebar placement needs one 200×200 file. A responsive campaign may legitimately need a 728×90 desktop asset and a 320×100 mobile asset because it serves into two different placement sizes.

Common website banner dimensions.

D14’s placement catalogue includes the following familiar options. Their names are convenient labels; where they belong depends on the publisher’s design.

• 728×90 leaderboard: a wide horizontal format commonly suited to desktop content widths.
• 468×60 full banner: a smaller horizontal format for narrower layouts.
• 970×90 super leaderboard and 970×250 billboard: large desktop formats that need generous page width.
• 300×250 medium rectangle and 336×280 large rectangle: versatile content or sidebar proportions.
• 250×250 square and 200×200 small square: compact square placements.
• 300×600 half page, 160×600 wide skyscraper and 120×600 skyscraper: tall formats for suitable side columns.
• 320×50, 320×100 and 300×50: horizontal formats for narrow mobile layouts.

A publisher can keep different formats as separate campaigns when they carry different prices or commercial terms. That avoids advertising a leaderboard inside a package whose actual placements are only sidebar squares.

Use several files only when delivery needs them.

A responsive website may use different placements at different viewport widths. When one campaign covers both, checkout requests one file for each distinct size so the delivery service can select suitable creative without distorting it.

The publisher controls which placements belong to the campaign. The system derives the required banner set from those placements; the buyer is not expected to guess or upload every size in the catalogue.

Keep the message consistent

Adapt the layout rather than merely shrinking it. A long desktop line may become unreadable in a 320×50 mobile banner. Preserve the identity, central promise and destination while simplifying detail for smaller canvases.

Choose the format for the artwork.

• WebP: a strong general choice for compact raster banners with broad modern-browser support.
• AVIF: can produce very small photographic files, but always inspect the exported result for detail and colour.
• JPEG: suitable for photographic imagery where transparency is unnecessary.
• PNG: useful for sharp raster graphics or transparency, though files can be larger.
• GIF: accepted for compatibility and simple animation; limited colour can make gradients and photographs look rough.
• SVG: ideal for crisp vector artwork when it is self-contained and safe.

D14 inspects SVG markup and rejects active or external content such as scripts, embedded foreign HTML and remote image references. A self-contained vector with explicit dimensions or a valid viewBox is the appropriate form.

Prepare legible, efficient artwork.

1. Design at the exact pixel dimensions for raster formats.
2. Keep important text and the call to action comfortably inside the edges.
3. Check contrast at the size visitors will actually see, not only on a zoomed canvas.
4. Use a clear advertiser identity and make the banner promise match the destination page.
5. Optimise the export beneath the file-size limit displayed at checkout.
6. Preview every variant independently; do not assume a resized master remains readable.

For SVG, keep fonts and assets self-contained without external dependencies. For animated GIF, make sure the first frame communicates enough if animation is delayed or not seen.

What the buyer supplies at checkout.

For an image advert, the buyer supplies the banner file or files and the destination URL. Checkout identifies every required dimension and the publisher-configured maximum file size. Each upload is checked for an accepted MIME type and exact dimensions rather than trusting the filename extension.

Payment creates a paid order pending publisher review. The publisher can inspect the banner and destination, accept it, request changes or decline it. A paid advert is not eligible to run merely because the file uploaded successfully.

Common banner creative questions.