Bluesky’s 1 MB limit is the real constraint — export at the right size as WebP or JPG and check the file size on every card.
One PNG, JPG, WebP, AVIF, GIF or BMP · every size below is generated from it
No size limit · files are processed on your device and never uploaded · how it works
Bluesky · 5 sizes
Bluesky keeps uploads under 1 MB, so export as WebP or JPG. Banners are 3:1 like X headers.
Add an image to see it in every size
1920×1080
Landscape post1920 × 1080 px · 16:9 · under 1 MB
1080×1350
Portrait post1080 × 1350 px · 4:5
1080×1080
Square post1080 × 1080 px · 1:1
1500×500
Banner1500 × 500 px · 3:1 · under 1 MB
400×400
Profile photo400 × 400 px · 1:1
1200×800
Custom size × px
Runs in your browser. Files are never uploaded — you can go offline after the page loads.
How to use the Bluesky Image Resizer
Drop one image — a photo, logo or design export.
Every size for this platform appears as a live preview with its dimensions and ratio.
Slide between Fit and Fill on any card and drag the preview to reposition; nothing is stretched.
Download a single size, or all of them as a ZIP.
Easy to use
Drop files, pick options, download. Whole folders at once, no signup, no daily limit.
Best quality
The same engines the professionals use — SVGO, resvg, MozJPEG, libwebp, libavif — compiled to run in your browser.
Private & secure
Files are processed on your device and never uploaded. Close the tab and nothing remains anywhere.
Bluesky caps image uploads at 1 MB, which is the main thing to plan for. Banners are 3:1 at 1500×500, profile photos 400×400, and posts display well at 16:9 (1920×1080), 4:5 (1080×1350) or square. The app accepts JPG, PNG and WebP; WebP at quality 85 comfortably stays under 1 MB at these sizes.
Every Bluesky size on this page, verified for 2026: Landscape post 1920×1080 px (16:9 · under 1 MB), Portrait post 1080×1350 px (4:5), Square post 1080×1080 px (1:1), Banner 1500×500 px (3:1 · under 1 MB), Profile photo 400×400 px (1:1). Each card is a live preview of your image in that frame — drag to reposition, slide between Fit (whole image, background added) and Fill (frame covered, edges cropped), then download the one you need or every size as a ZIP. Nothing is uploaded; the rendering runs in your browser.
1500×500 pixels (3:1), under 1 MB — the same shape as an X header.
Why does Bluesky reject my image?
Almost always the 1 MB limit. Export as WebP or JPG at quality 80–85 at the display size; each card shows the resulting file size after rendering.
What size is a Bluesky landscape post in 2026?
1920×1080 pixels (16:9), under 1 MB — 16:9 · under 1 MB. Drop your image above and the landscape post card renders it at exactly that size; use the Fit/Fill slider to choose between showing the whole picture and filling the frame.
What size is a Bluesky portrait post in 2026?
1080×1350 pixels (4:5), under 1 MB — 4:5. Drop your image above and the portrait post card renders it at exactly that size; use the Fit/Fill slider to choose between showing the whole picture and filling the frame.
Most online converters upload your file to a server. InfyTool ships the actual encoders to your browser as WebAssembly instead, so processing happens inside your tab — faster for batches, and nothing to delete afterwards.
No upload, ever. Turn off Wi-Fi after the page loads and every tool keeps working.
No limits. No file-size cap, no queue, no watermark, no account.
Runs on your CPU. Batches use several cores in parallel; nothing is throttled.