Carousel Ad Specifications
A carousel ad contains a headline, up to six images, and a destination URL. Images will be shown in feed and conversation placements. When clicked, redditors are taken to that image’s landing page.
You can choose to enable comments for this ad type.
Text
| Maximum length | Quantity | Required | |
|---|---|---|---|
| Headline | 300 characters Recommended: ≤ 100 characters Safer limit: ≤ 80 characters | 1 | |
| Destination URL | 268 characters | 1 for each image | |
| Caption | 50 characters | 1 for each image | |
| Display URL | 100 characters This must match your destination URL’s domain (e.g., reddit.com) | 1 for each image |
Image
We strongly recommend using the same aspect ratio for all images.
In most cases, any aspect ratio can be used, but it may cause formatting issues, like black bars appearing. Follow our recommendations to limit issues.
| Required files | 2–6 |
|---|---|
| File type | JPG, PNG, or GIF |
| File size | GIFs: 3 MB Other file types: 20 MB |
| Recommended GIF length | 3–10 seconds |
| Call to action | Choose from options |
Cross-device
| Ratio | Resolution | |
|---|---|---|
 | Portrait 4:5 | 1200 x 1500 px |
 | Landscape 4:3 | 1440 x 1080 px |
 | Landscape 16:9 | 1920 x 1080 px |
Mobile
| Ratio | Resolution | |
|---|---|---|
 | Square 1:1 | 1200 x 1200 px |
| Portrait 4:5 | 1200 x 1500 px |
| Landscape 4:3 | 1440 x 1080 px |
| Landscape 16:9 | 1920 x 1080 px |
Desktop
| Ratio | Resolution | |
|---|---|---|
| Portrait 4:5 | 1200 x 1500 px |
| Landscape 4:3 | 1440 x 1080 px |
| Landscape 16:9 | 1920 x 1080 px |
Thumbnail (for compact view)
This image is only shown in compact view and is automatically generated based on the first image in the carousel. This image can be replaced with an uploaded file.
| File type | JPG, PNG, or GIF |
|---|---|
| Maximum file size | 3 MB |
Recommended resolutions
| Ratio | Resolution | |
|---|---|---|
 | Landscape 4:3 | 400 x 300 px |
Acceptable suggestions
Using a thumbnail with these or other ratios may cause formatting issues.
| Ratio | Resolution | |
 | Square 1:1 | 300 x 300 px |
Things to know
- Combine feed and conversation to show ads across all placements and maximize performance.
- Use the highest resolution that meets the ratio requirements for best quality.
- In most cases, any aspect ratio can be used but may cause formatting issues, like black bars appearing. Follow our recommendations to limit issues.
- Text may be truncated due to factors like browser, device, and font display size. We recommend limiting headlines to 100 characters, or 80 characters if truncation is a concern.
- Use Crop image in ad setup to streamline changing the aspect ratio and cropping of images in your ad.
- We recommend experimenting with different ad types to see what resonates most with your audience. Learn more about our creative best practices.
- A thumbnail will be automatically generated based on the media in your ad for all types except for freeform. You can choose to replace this by uploading a different image.
