English 
Русский 
Español 
Deutsch 
Français 
Українська
450×350
shown at 49%
Headliner - Desktop Side Graphics (450x350)
Other
- Size (px)
- Ratio
- 450:350
Reddit Ads — Image/Video Ad Thumbnail (classic-mode)
Other · Social · Verified 2026-06
Live preview
400×300
shown at 100%
In context
Sample feed post
Full specification
Size (px)
Ratio4:3
Max weight500 KB
FormatsJPG, PNG, GIF
Text limits n/a
Notes & best practice
Optional small thumbnail for classic and compact feed views.
Size must be 400x300 (4:3) with a maximum weight of 500 KB.
This is separate from the larger custom video poster or free-form thumbnail (JPG or PNG up to 3 MB).
Thumbnails are auto-generated from the media for most ad types, but free-form ads require a manual upload.
Frequently asked questions
What size is the Reddit Ads Image/Video Ad Thumbnail (classic-mode)?
The Reddit Ads Image/Video Ad Thumbnail (classic-mode) is 400×300 px, aspect ratio 4:3.
What is the aspect ratio of the Reddit Ads Image/Video Ad Thumbnail (classic-mode)?
4:3. At the recommended resolution that is 400×300 px.
What is the maximum file size for the Reddit Ads Image/Video Ad Thumbnail (classic-mode)?
Up to 500 KB, in JPG, PNG, GIF.
What file formats does Reddit Ads accept for the Image/Video Ad Thumbnail (classic-mode)?
JPG, PNG, GIF.
Why does Reddit Ads crop my Image/Video Ad Thumbnail (classic-mode)?
Reddit Ads shows Image/Video Ad Thumbnail (classic-mode) at 4:3. Upload exactly 400×300 px and keep key content in the safe area so nothing gets cut off.
Is 400×300 still correct for the Reddit Ads Image/Video Ad Thumbnail (classic-mode) in 2026?
Yes. Last verified 2026-06 against the official Reddit Ads documentation.
Check your creative
Test a file against this exact spec before you upload it anywhere.
Nothing is uploaded or saved — the check runs entirely in your browser.