300×50 Ad Size: Mobile Banner
The 300×50 mobile banner is an older, slightly narrower version of the 320×50. It is still accepted by many ad networks as a fallback size.
Specs
| Spec | Value |
|---|---|
| Name | Mobile Banner |
| Dimensions | 300 × 50 pixels |
| Aspect ratio | 6:1 |
| Devices | Mobile |
| High-resolution version | 600 × 100 pixels (2×), scaled down |
| Typical file size | Keep images under 150 KB. Google Ads limits uploaded image ads to 150 KB. |
| Formats | JPG, PNG, GIF or HTML5 |
Where to place a 300×50 ad
- Mobile banner slots
Pros and cons
| Pros | Cons |
|---|---|
| ✓ Fits the smallest screens | ✗ Little demand on its own |
Tips for 300×50 ads
- Only use it as a fallback inside a 320×50 slot.
- Reserve the slot’s height in your layout so the page doesn’t jump when the ad loads. See Core Web Vitals and ads.
Related ad sizes
Frequently asked questions
Is 300×50 still used?
Mostly as a fallback. Most mobile banner demand is for 320×50.
What is the difference between 300×50 and 320×50?
Only the width. The 320×50 matches the width of older phones and is the standard.
Want to know what this slot could earn? Try the ad revenue calculator, or look up terms in the ad tech glossary.