320×50 Ad Size: Mobile Leaderboard
The 320×50 mobile leaderboard is the standard small banner on phones. It is often used as a sticky anchor ad at the bottom of the screen, where it stays in view.
Specs
| Spec | Value |
|---|---|
| Name | Mobile Leaderboard (also called mobile banner) |
| Dimensions | 320 × 50 pixels |
| Aspect ratio | 32:5 |
| Devices | Mobile |
| High-resolution version | 640 × 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 320×50 ad
- Sticky anchor at the bottom of the screen
- Top of the page on mobile
Pros and cons
| Pros | Cons |
|---|---|
| ✓ Fits every phone ✓ High viewability when sticky | ✗ Small, so CPMs per ad are lower ✗ Easy to tap by accident if placed near buttons |
Tips for 320×50 ads
- Allow 320×100 in the same slot for higher prices.
- Keep it away from navigation buttons to avoid accidental clicks.
- Reserve the slot’s height in your layout so the page doesn’t jump when the ad loads. See Core Web Vitals and ads.
Make a 320×50 banner for free →
Related ad sizes
- 320×100 Large Mobile Banner
- 300×50 Mobile Banner
- 728×90 Leaderboard
- All banner ad sizes with live previews
Frequently asked questions
What is the best mobile banner size?
320×50 is the most common, while 320×100 and 300×250 usually earn more per ad.
Can I make 320×50 sticky?
Yes. A bottom anchor is the usual use. Check your ad partner’s rules for sticky ads.
Want to know what this slot could earn? Try the ad revenue calculator, or look up terms in the ad tech glossary.