Display ad sizes and specifications

Standard display sizes

Placement	Dimensions	Best use
Medium rectangle	300 × 250 px	Articles and sidebars
Leaderboard	728 × 90 px	Desktop headers
Mobile banner	320 × 50 px	Mobile placements
Half page	300 × 600 px	High-attention sidebars
Large rectangle	336 × 280 px	Editorial content

If you can only produce one size, produce the 300 × 250. Every publisher we work with accepts it and it performs well in both desktop and mobile layouts. The full list, including premium and legacy sizes, is on the specification sheet.

Retina and scaling

Export display creative at its stated size. Publishers’ ad systems do not scale a 600 × 500 file down to 300 × 250 — they reject it. Where a publisher supports high-resolution creative we will ask for it specifically.

Accepted file formats

• JPG
• PNG
• GIF
• WebP

Use JPG or WebP for photography. Use PNG when transparency or very sharp type is required. GIF is for simple animation only — its colour palette is limited to 256 colours, so photographs look poor. HTML5 creative is accepted by some publishers on request; ask before building it.

File weight

Size	Maximum weight
320 × 50	50 KB
320 × 100	80 KB
300 × 250, 336 × 280, 728 × 90, 160 × 600	150 KB
300 × 600	200 KB
970 × 250	250 KB

Weight matters because slow creative is skipped by readers and, increasingly, rejected by publishers. A JPG exported at quality 75–80 almost always lands under the limit. See PNG, JPG, SVG or WebP? for export settings.

Animation

• Maximum 15 seconds total, 3 loops, then stop.
• No flashing or strobing (nothing faster than 3 flashes per second).
• The final frame must carry the full message: offer, brand and call to action. Many readers only see that frame.
• Keep the first frame legible on its own too — some publishers show it as a static fallback.

Design for the size

Small units are read at a glance from arm’s length. A few habits make the difference:

• One message per unit. A headline, a supporting line at most, and a call to action.
• Type no smaller than 11 px at actual size; 14 px or larger on the 320 × 50.
• Keep a 2–4 px contrasting border or visible edge so the ad does not merge with the page.
• Logo in the same corner in every size, so the set reads as one campaign.
• The call to action looks like a button. People click things that look clickable.

Name files clearly

brand-campaign-placement-300x250-v2.png

Include the size in the name so nobody has to open the file to check. Full convention in File naming.

Creative checklist

Download the ad spec sheet