UtilToolkits2025-12-25
TL;DR — Use the Image Resizer to scale any image to exact pixels with aspect-ratio lock and platform presets. Verify proportions with the Aspect Ratio Calculator; finish the pipeline with the Image Compressor for the smallest possible file.
| Where | Dimensions (px) | Ratio |
|---|---|---|
| Open Graph / Twitter card | 1200 × 630 | 1.91:1 |
| Favicon / app icon | 512 × 512 | 1:1 |
| YouTube thumbnail | 1280 × 720 | 16:9 |
| LinkedIn banner | 1584 × 396 | 4:1 |
| LinkedIn post image | 1200 × 627 | 1.91:1 |
| Instagram square post | 1080 × 1080 | 1:1 |
| Instagram portrait post | 1080 × 1350 | 4:5 |
| Instagram story / Reel | 1080 × 1920 | 9:16 |
| X (Twitter) post | 1600 × 900 | 16:9 |
| Facebook cover | 820 × 312 | ≈2.6:1 |
Run the math first with the Aspect Ratio Calculator — paste current width and height, get the simplified ratio plus suggested target dimensions.
The resizer uses the browser’s Canvas API. Your image is read locally, scaled locally, and downloaded locally. No upload, useful when the photo is unreleased marketing or contains people you can’t share with a third-party server.
The smallest size that still looks crisp at the rendered display size — typically 2× the display width. There’s no fixed answer; the goal is to ship the fewest bytes that look good.
Downscaling has minimal visible loss with a good algorithm (Lanczos, Mitchell). Upscaling always loses quality.
4:5 portrait (1080 × 1350) takes the most feed space and gets more engagement than square (1:1).
Resize first. Compressing a 4000-px-wide image then downscaling later wastes work and softens the result.