!social media
Why Getting Dimensions Wrong Is Costly
Every platform re-compresses images that do not match its expected dimensions. Upload a 4K photo to Instagram and it will downsample it to 1080px wide, apply its own compression, and serve the result. You have no control over how aggressively it compresses. The only way to control output quality is to
resize to the exact target dimensions before uploading — then the platform's compression has less work to do.
Additionally, wrong aspect ratios get cropped automatically. If your subject or text is near the edges, it disappears.
2026 Size Reference by Platform
Instagram
| Format | Dimensions | Notes |
|---|
| Square Post | 1080 x 1080 px | Safe for all feeds |
| Portrait Post | 1080 x 1350 px | Maximum vertical space |
| Landscape Post | 1080 x 566 px | For panoramic content |
| Stories / Reels | 1080 x 1920 px | Keep content out of top/bottom 250px |
X (Twitter)
| Format | Dimensions |
|---|
| Timeline Image | 1200 x 675 px |
| Header / Banner | 1500 x 500 px |
LinkedIn
| Format | Dimensions |
|---|
| Profile Banner | 1584 x 396 px |
| Post Image | 1200 x 627 px |
YouTube
| Format | Dimensions |
|---|
| Thumbnail | 1280 x 720 px |
| Channel Banner | 2560 x 1440 px |
How the Resizer Works
The
Image Resizer uses Lanczos-3 interpolation via the Canvas API. Lanczos-3 is a sinc-based filter that calculates each output pixel as a weighted sum of nearby input pixels. Compared to bilinear interpolation, it preserves sharpness when downscaling — edges and text stay crisp rather than blurring.
Profile Photos: The Circular Crop Problem
Most platforms display profile photos as circles, but the uploaded image is still square. The circular crop happens on the platform's side. Keep your subject centered, leave some padding around the edges — anything in the outer 15% may be cut off — and upload at the maximum supported resolution.
Stories and Reels: Safe Zones
For 1080x1920 Stories/Reels, the bottom ~250px and top ~250px are covered by UI elements. Keep important content in the middle 60% of the vertical frame — the safe zone guaranteed to be visible across all devices.