Mastodon Image & Video Sizes
Every Mastodon image and video size for 2026: exact dimensions, aspect ratios, and file specs for posts, stories, profiles, ads, and thumbnails — in one reference.
All current Mastodonimage and video dimensions for 2026. Dimensions are in pixels (width × height). Aspect ratios marked with ~ are approximate.
Mastodon Posts
| Surface | Dimensions (px) | Ratio | Notes |
|---|---|---|---|
| Post Image (Landscape) | 1280 × 720 | 16:9 | Mastodon resizes images to fit; exact file-size limits vary by instance (typically 16 MB max). |
| Post Image (Square) | 1200 × 1200 | 1:1 | Square images display cleanly across all Mastodon clients. |
| Post Image (Portrait) | 900 × 1200 | 3:4 | Portrait images are cropped to a 3:2 preview in timeline; tap to see full image. |
Mastodon Videos
| Surface | Dimensions (px) | Ratio | Notes |
|---|---|---|---|
| Video | 1920 × 1080 | 16:9 | Max file size typically 40 MB (varies by instance). MP4 or WebM recommended. |
Mastodon Profile
| Surface | Dimensions (px) | Ratio | Notes |
|---|---|---|---|
| Profile Photo | 400 × 400 | 1:1 | Max 2 MB. Displayed as a circle or square depending on client. PNG or JPG. |
Mastodon Cover & Banner
| Surface | Dimensions (px) | Ratio | Notes |
|---|---|---|---|
| Header / Banner Image | 1500 × 500 | 3:1 | Max 2 MB. Displayed behind your profile photo; crop may vary by client. |
How it works
- 1
Find the right surface
Browse the grouped tables — Posts, Stories & Reels, Profile, Cover & Banner, or Ads — and locate the surface that matches what you're creating.
- 2
Design at native resolution
Create your asset at the exact pixel dimensions listed. Scale down only after designing at full resolution to keep edges crisp.
- 3
Respect the aspect ratio
Most platforms crop to the listed ratio if you upload a mismatched size. Check the Notes column for safe-zone boundaries before placing text or logos.
Frequently asked questions
What is the best Mastodon image size?
The recommended Mastodon image size is 1280 × 720 (16:9). Mastodon resizes images to fit; exact file-size limits vary by instance (typically 16 MB max).
What size is the Mastodon profile photo?
The Mastodon profile photo should be 400 × 400 (1:1). Max 2 MB. Displayed as a circle or square depending on client. PNG or JPG.
What aspect ratio does Mastodon use?
Mastodon supports multiple aspect ratios depending on the content type. The primary format is 16:9 (1280 × 720). Always check the spec table above for the exact ratio of each surface.
What file format should I use for Mastodon images?
JPEG is best for photographs and complex imagery. PNG is better for graphics, text, or anything with transparency. Keep file sizes as small as possible without visible quality loss to improve load speed and avoid compression artifacts on upload.
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