What this is
This article explains how ad sizes impact campaign delivery and provides best practices to ensure your ads are eligible to appear across available placements.
Ad delivery depends not only on your audience and bid, but also on whether your creatives match the formats required by different placements.
When to use this
Use this guide when:
Your ads are not appearing or have low delivery
You want to improve campaign reach and visibility
You are preparing creatives before launching a campaign
Why ad sizes matter
Ad platforms serve ads across a wide variety of placements, including websites, mobile apps, and social environments.
Each placement supports specific formats and dimensions.
If your campaign does not include a matching ad size, your ad cannot be served in that placement.
In practice, this means:
Fewer ad sizes → fewer delivery opportunities
More coverage → more chances to serve ads
Additionally, a significant portion of available inventory comes from mobile and in-app environments, where different formats are commonly used.
How missing ad sizes affects delivery
One of the most common reasons ads do not appear is no eligible ad for the available placement
This happens when:
The placement requires a specific format (e.g., horizontal banner)
Your campaign does not include a matching creative
For example:
A placement may require a 728 × 90 leaderboard
If that size is not included, your ad will not be served there
Even if your bid and audience are correct, missing sizes alone can prevent delivery.
Mobile-first considerations
A large share of ad impressions occurs on mobile devices, especially in in-app environments.
Because of this:
Mobile formats represent a significant portion of available inventory
Campaigns without mobile-friendly sizes may have limited reach
Common mobile formats include:
320 × 50 (Mobile Banner)
320 × 100 (Large Mobile Banner)
300 × 600 (Mobile Full Page)
320 × 480 (Mobile Interstitial)
Including these formats helps ensure your ads can participate in mobile placements.
Best practices to improve delivery
Include multiple ad sizes
Do not rely on a single format.
Providing a range of sizes increases the number of placements where your ads are eligible to serve.
Cover different layout types
Include a mix of:
Horizontal formats (e.g., 728 × 90)
Square formats (e.g., 300 × 250)
Vertical formats (e.g., 160 × 600, 300 × 600)
This ensures coverage across different placement types.
Prioritize mobile-friendly formats
Since a large portion of impressions occurs on mobile:
Include mobile banner and vertical formats
Avoid relying only on desktop-sized creatives
Avoid limited creative setups
Campaigns with only one or two sizes may struggle to deliver, even with a strong audience and competitive bid.
Review sizes if delivery is low
If your campaign is not delivering:
Check whether your creatives cover multiple formats
Add additional sizes before adjusting other variables
Design vertical creatives for visibility
For vertical ads used in story-style placements (such as TikTok, Instagram Stories, Facebook Stories, and Reddit vertical placements), avoid placing important copy near the bottom of the creative.
Platform UI elements may overlap or cut off lower portions of the ad.
To improve visibility:
- Place important copy toward the top of the creative
- Keep key messaging within safe visible areas
- Avoid placing critical text near the bottom edge of the design
This helps ensure your messaging remains visible across vertical placements and devices.
Supported ad sizes
Below is a list of commonly supported ad sizes across display, mobile, and social placements.
IAB Standard Display
300 × 250 (Medium Rectangle)
336 × 280 (Large Rectangle)
728 × 90 (Leaderboard)
160 × 600 (Wide Skyscraper)
300 × 600 (Half Page)
970 × 250 (Billboard)
970 × 90 (Super Leaderboard)
120 × 600 (Skyscraper)
Large Format & Rising Stars
300 × 1050 (Portrait)
300 × 600 (Filmstrip)
970 × 90 → 970 × 415 (Pushdown)
300 × 250 → 970 × 550 (Sidekick)
980 × 120 (Panorama)
Smaller Standard Units
120 × 90 (Button 1)
120 × 60 (Button 2)
200 × 200 (Small Square)
250 × 250 (Square)
240 × 400 (Vertical Rectangle)
Banner Variations
468 × 60 (Full Banner)
234 × 60 (Half Banner)
300 × 100 (3:1 Rectangle)
125 × 125 (Square Button)
720 × 300 (Pop-Under / Interstitial)
Mobile
320 × 50 (Mobile Banner)
320 × 480 (Mobile Interstitial)
320 × 100 (Large Mobile Banner)
300 × 600 (Mobile Full Page)
300 × 50 (Smartphone Banner)
216 × 36 (Feature Phone Banner)
Social Media
1200 × 628 (Facebook Feed, LinkedIn)
1080 × 1080 (Facebook / Instagram Square)
1080 × 1920 (Instagram Story / Reel)
1080 × 1350 (Instagram Portrait)
800 × 418 (Twitter / X Card)
300 × 250 (YouTube Display)
728 × 90 (YouTube Leaderboard)
Important notes
Ad delivery depends on having creatives that match available placements
Missing ad sizes can limit or prevent delivery, even if other settings are correct
Including a wide range of formats increases the likelihood of consistent delivery