BlueSky Sizes & Dimensions Guide
Bluesky image and video sizes for posts and clips, with the file limits the network enforces. PostFast sizes them automatically.
All BlueSky Sizes at a GlanceUpdated 2026
Every BlueSky content type with its recommended dimensions, aspect ratio, and limits. Tap any content type for the full specification.
Why BlueSky sizes matter
Bluesky enforces tight file-size limits, so large images and video are rejected or must be compressed before they upload. Sizing media correctly means your posts publish reliably and still look sharp in the feed.
BlueSky content specificationsUpdated 2026
Post
Updated 2026Post images work well around 1000x1000px (1:1) and must stay under the platform's small file-size limit, so compress before uploading. You can attach multiple images per post.
Video
Updated 2026Bluesky video is 1920x1080px (16:9) with a tight file-size cap, so keep clips short and compressed. Upload as MP4.
BlueSky best practices and common mistakes
Best practices
- ✓Keep images near 1000x1000px and compress them to fit the small file-size limit.
- ✓Use MP4 video and keep clips short to stay under the size cap.
- ✓Add alt text, which the Bluesky community expects.
- ✓Use JPG or WebP to keep image files small without losing much quality.
Common mistakes to avoid
- ✗Uploading large, uncompressed images that exceed the file-size limit.
- ✗Trying to upload long or high-bitrate video that is too large.
Developer Resources
BlueSky API Guides
Learn how to schedule BlueSky content programmatically via API
Frequently asked questions about BlueSky sizes
What are the BlueSky image and video sizes in 2026?
BlueSky sizes by content type: Post 1000×1000px, Video 1920×1080px. See the table above for the aspect ratio, file size, and supported formats of each one.
What is the best image size for BlueSky?
The recommended image size for BlueSky is 1000×1000px (1:1), used for posts. Upload at this size to avoid cropping and limit compression.
What aspect ratios does BlueSky use?
BlueSky uses 1:1 for posts and 16:9 for videos.
How long can BlueSky videos be?
On BlueSky, Video up to 180 seconds (3 minutes).
What file formats does BlueSky support?
Across its content types, BlueSky supports JPG, JPEG, PNG, GIF, WEBP, and MP4. Use JPG for photos, PNG for graphics with text, and MP4 for video.
Why will my image or video not upload to Bluesky?
Bluesky has strict file-size limits (images up to about 2MB, video up to about 100MB). If your file is too large it will be rejected. Compress the image or shorten and re-encode the video, then try again.
Do I need alt text on Bluesky?
Alt text is not strictly required, but the Bluesky community strongly expects it for accessibility, and it can help reach. Add a short description of each image when you post.
Sizes for other platforms
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