Bluesky Image Sizes in 2026 (Avatar, Banner & Post Specs)
Last updated: May 2026.
The right Bluesky image sizes in 2026 are simple: 400×400 for your avatar, 1500×500 for your banner, and roughly 1000px on the longest side for post images. Get them right and your visuals look crisp and uncropped; get them wrong and Bluesky's compression or feed cropping can leave you with a blurry avatar or a banner with the key part cut off.
This is your quick-reference guide to every Bluesky image dimension — profile, posts, and video — plus the aspect ratios and file limits that matter. Because strong visuals earn faster early engagement, getting these specs right is a small detail that quietly helps your reach on a fast-growing network. Bookmark it for whenever you're sizing an image for Bluesky.
TL;DR
- Avatar: 400×400 px (1:1), displayed as a circle
- Banner: 1500×500 px (3:1) — keep key elements centered, mobile crops the sides
- Post images:
1000px on the longest side; best ratios are 1:1 (1080×1080), landscape (1200×627), and portrait (~627×1200) - Up to 4 images per post, JPG/PNG/GIF/WebP, around 1MB each (Bluesky compresses larger files)
- Video: up to 3 minutes, max 100MB; 16:9, 9:16, or 1:1
- Always add alt text — it's good for accessibility and discovery
Table of Contents
- Bluesky Image Sizes at a Glance
- Every Bluesky Image Spec
- Tips for Sharp Bluesky Images
- FAQs
- Next Steps
Bluesky Image Sizes at a Glance
| Asset | Dimensions | Aspect ratio | Notes |
|---|---|---|---|
| Avatar | 400×400 px | 1:1 | Displayed as a circle |
| Banner | 1500×500 px | 3:1 | Sides crop on mobile; center key elements |
| Post image (square) | 1080×1080 px | 1:1 | Safest all-rounder |
| Post image (landscape) | ~1200×627 px | ~1.91:1 | Good for link-style visuals |
| Post image (portrait) | ~627×1200 px | ~4:5 | Takes more vertical feed space |
| Video | 1920×1080 / 1080×1920 / 1080×1080 | 16:9 / 9:16 / 1:1 | Up to 3 min, 100MB |
These match the practical specs documented across current Bluesky media guides. When in doubt, square (1:1) is the safest choice — it displays cleanly everywhere and cross-posts neatly to X and Threads.
Every Bluesky Image Spec
Profile Avatar
Your avatar should be 400×400 pixels (1:1). Bluesky displays it as a circle throughout the app, so keep your face or logo centered and away from the corners, which get clipped by the circular crop. Accepted formats are PNG and JPG, with a file limit around 1MB. A clean, high-contrast avatar reads better at the small sizes it appears in feeds and replies.
Profile Banner
Your banner should be 1500×500 pixels (3:1) — the same proportions as a classic header image. Two things to watch: on mobile, the banner crops slightly tighter on the sides, and your avatar overlaps the bottom-left corner. Keep text and faces in the center, away from the edges and that lower-left zone, so nothing important gets hidden. The file limit is around 1MB.
Post Images
Post images are the ones you'll size most often. Bluesky caps images at roughly 1000px on the longest side and compresses larger files — a constraint of how the open AT Protocol handles media — so there's little point uploading enormous images. You can attach up to 4 images per post in JPG, PNG, GIF, or WebP.
For ratios:
- 1:1 square (1080×1080) — the safest, displays cleanly in-feed
- Landscape (~1200×627, ~1.91:1) — good for graphics and link-style cards
- Portrait (~627×1200, ~4:5) — claims more vertical space in the feed, which can boost attention
If you reuse images across networks, mind the differences — our social media aspect ratios reference shows how each platform crops the same image, which matters when you cross-post to X and Bluesky.
Video
Bluesky supports video up to 3 minutes and 100MB. Stick to standard ratios — 16:9 (1920×1080) for landscape, 9:16 (1080×1920) for vertical, or 1:1 (1080×1080) for square. Add captions for accessibility and silent autoplay.
Tips for Sharp Bluesky Images
A few practices keep your Bluesky visuals looking their best:
- Pre-size before uploading. Export at the target dimensions so Bluesky's compression has less to do — uploading a massive file just gets it squeezed down anyway.
- Center the important stuff. Feed and mobile crops can trim edges, so keep faces, text, and logos toward the middle.
- Always add alt text. It's essential for accessibility and helps describe your image to the feeds and search that surface content.
- Pair text with images. Visual posts tend to earn faster early engagement, which helps reach — just don't let an image be an afterthought.
- Keep files lean. Around 1MB or under avoids heavy compression and keeps things crisp.
- Generate visuals fast. Our AI image generator can produce on-brand graphics at the right dimensions when you need them.
- Use WebP where you can. WebP holds quality at smaller file sizes, so your images survive Bluesky's compression with less degradation than a heavy JPG or PNG.
- Check it on mobile. Most Bluesky users scroll on phones, so preview how your banner and post images crop on a small screen before you commit to them.
Nailing these specs is a small thing, but it's the difference between a feed that looks polished and one that looks careless — and on a platform where visuals help you get noticed, polish counts — especially with Bluesky's audience growing through 2026 and more people seeing every post.
Schedule pixel-perfect Bluesky posts. PostEverywhere lets you upload, size, and schedule your Bluesky images alongside every other network. Start free →
Why Bluesky Image Sizes Matter for Reach
It's tempting to treat image specs as a nitpick, but on Bluesky they connect directly to performance. Posts with images tend to earn faster early engagement, and early engagement is what pushes a post into the Discover feed. A crisp, correctly-sized image stops the scroll; a blurry or awkwardly-cropped one gets skipped before it can earn a like or repost.
The same logic applies to your profile. When a strong post earns you a profile visit, a sharp avatar and a banner that isn't cut off are part of what converts that visitor into a follower. A profile that looks careless quietly undoes the work your content just did. These are tiny fixes with outsized payoff, because you're improving the impression every post and every profile visit makes — multiplied across thousands of views.
And if you publish the same visuals to other networks, sizing for Bluesky first and adjusting per platform saves rework. Bluesky, X, and Threads crop images differently, so a graphic that looks perfect on one can lose its edges on another — our aspect ratios guide maps exactly how each platform handles the same file.
Size once, schedule everywhere. PostEverywhere lets you upload Bluesky-ready images and publish them across every network from one place — sized right, scheduled, and consistent. See plans →
FAQs
What is the best Bluesky image size?
For post images, 1080×1080 (1:1 square) is the safest all-rounder and displays cleanly everywhere. Your avatar should be 400×400 and your banner 1500×500. Bluesky caps images around 1000px on the longest side and compresses larger files.
What size is a Bluesky banner?
A Bluesky banner is 1500×500 pixels (3:1 aspect ratio). On mobile the sides crop slightly tighter, and your avatar overlaps the bottom-left corner, so keep important text and faces centered and away from those edges.
What size should my Bluesky profile picture be?
Your Bluesky avatar should be 400×400 pixels (1:1). It's displayed as a circle throughout the app, so center your face or logo and avoid the corners, which get clipped. PNG and JPG are accepted, up to about 1MB.
How many images can you post on Bluesky?
You can attach up to 4 images per Bluesky post. Supported formats are JPG, PNG, GIF, and WebP, each around 1MB (Bluesky compresses larger files). Images are capped at roughly 1000px on the longest side.
What's the best aspect ratio for Bluesky posts?
Square (1:1) is the safest and displays cleanly in-feed. Portrait (around 4:5) claims more vertical space and can draw more attention, while landscape (around 1.91:1) suits graphics and link-style visuals. Match the ratio to the content.
Can you post video on Bluesky and what are the limits?
Yes. Bluesky supports video up to 3 minutes long and 100MB, in 16:9, 9:16, or 1:1. Add captions for accessibility and for the silent autoplay most users scroll with.
Next Steps
Bookmark these specs, size your images once, and you'll never ship a cropped banner or blurry avatar again.
- Schedule sized-right posts — upload and queue your Bluesky images with PostEverywhere
- Make visuals that spread — see how to go viral on Bluesky
- Cross-post without crop surprises — check the aspect ratios reference before posting to X and Bluesky
- Learn the workflow — our guide to scheduling Bluesky posts
Founder & CEO of PostEverywhere. Writing about social media strategy, publishing workflows, and analytics that help brands grow faster.