Reddit Video Ad Specs (2026): Sizes, Length, File Size & Format
Reddit video ads must be MP4 or MOV files (ProRes isn't supported), up to 1 GB, at up to 30 frames per second, and between 2 seconds and 15 minutes long. Reddit recommends 5 to 30 seconds. You can use five aspect ratios: 4:3 (1440 x 1080), 16:9 (1920 x 1080), 1:1 (1200 x 1200), 4:5 (1200 x 1500) and 3:4 (900 x 1200). Specs checked against Reddit's Video Ad Specifications in October 2026.
What are the Reddit video ad specs in 2026?
Spec | Requirement |
|---|---|
File type | MP4 or MOV (ProRes isn't supported) |
Max file size | 1 GB |
Max frame rate | 30 FPS |
Length | 2 seconds to 15 minutes |
Recommended length | 5 to 30 seconds |
Headline | Up to 300 characters (we keep ours under 150) |
Thumbnail | JPG, PNG or GIF, up to 3 MB, same aspect ratio as the video |
Playback | Autoplays in the feed on desktop and mobile; users can opt out |
What video sizes and aspect ratios does Reddit support?
Aspect ratio | Resolution | When to use it |
|---|---|---|
4:5 portrait | 1200 x 1500 px | Mobile feeds. Our first pick |
4:3 landscape | 1440 x 1080 px | Works on desktop and mobile. Our second pick |
1:1 square | 1200 x 1200 px | A safe choice across placements |
16:9 landscape | 1920 x 1080 px | Trailers and cinematic footage |
3:4 portrait | 900 x 1200 px | A tall option when you shoot vertical |
Reddit says any aspect ratio can be used, but off-ratio videos may be letterboxed or formatted badly. For best results, use a single video for multiple devices, placements and view modes. Reddit's own best practices prioritize 4:5 or 4:3, and we agree.
For context, 23% of the 5,824 ads we pulled through the Reddit Ads API are video, and 48% of gaming ads are.
How long should a Reddit video ad be?
Reddit allows 2 seconds to 15 minutes and recommends 5 to 30 seconds. Because videos autoplay in the feed, the first seconds do most of the work. Put your point up front, and for games, show real gameplay early. If you use a logo, put it in the first 3 seconds or the final 3 seconds. Keep it short and simple: one video, one message.
What are the thumbnail rules for Reddit video ads?
A thumbnail can be a JPG, PNG or GIF up to 3 MB, and it should match your video's aspect ratio. It's shown before the video plays, and uploading one replaces the frame Reddit picks for you.
Can you use video in other Reddit ad types?
Free-form ads can include up to 5 videos and 20 images, with up to 40,000 characters of text. Carousel ads use images. See our Reddit ad types explained and Reddit's Ad Unit Specifications.
What are the most common Reddit video ad mistakes?
Uploading the wrong format. Only MP4 and MOV work, and ProRes doesn't.
Using an off-ratio video that gets letterboxed.
Putting the point at the end of a long video, when people decide in the first seconds.
Skipping captions. Plenty of people watch feed video with the sound off.
Reusing a polished TV-style ad. Reddit rewards creative that looks native, not slick.
Reddit video ad specs: FAQ
What file types does Reddit accept for video ads?
MP4 and MOV. ProRes isn't supported.
What's the maximum file size for Reddit video ads?
1 GB.
How long can a Reddit video ad be?
From 2 seconds to 15 minutes. Reddit recommends 5 to 30 seconds.
What aspect ratio is best for Reddit video ads?
Start with 4:5 or 4:3. Reddit supports 4:3, 16:9, 1:1, 4:5 and 3:4, and other ratios may be letterboxed.
Do Reddit video ads autoplay?
Yes, in the feed on desktop and mobile. Users can opt out of autoplay.
What's the maximum frame rate for Reddit video ads?
30 FPS.
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About the author
Written by Dāvis Lejnieks, CEO of Undecided Agency and a Redditor for 15+ years. He plans and runs Reddit ad campaigns for DTC, gaming and app brands, and shares what the data shows here.
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