Resizing an image sounds simple, but doing it right, hitting exact dimensions without stretching or blurring, takes a little know-how. You can resize an image online by pixels or percentage, lock the aspect ratio, and use ready-made presets for social media.
Aspect ratio: the golden rule
An image's aspect ratio is the relationship between its width and height. If you change one without the other, the picture stretches and looks wrong. Keeping the aspect ratio locked means when you set a new width, the height adjusts automatically to match, no distortion.
How to resize an image (step by step)
- Open the Resize Image tool and upload your picture.
- Pick a mode: exact Pixels, or scale by Percent.
- Enter dimensions or tap a preset. Keep the lock on to preserve proportions.
- Resize and download.
Common social media sizes
| Platform | Size |
|---|---|
| Instagram square | 1080 × 1080 |
| Instagram story | 1080 × 1920 |
| Facebook / OG share | 1200 × 630 |
| YouTube thumbnail | 1280 × 720 |
Tips
- Use presets for social posts to hit the exact size platforms expect.
- Resize before compressing for the smallest final file, then run it through the compressor.
- Need a different format too? Use the converter afterwards.
📐 Ready to resize image?
Free, private and instant, right in your browser.
Open the Resize Image tool →Frequently asked questions
How do I resize an image to exact dimensions?
Upload your image, choose Pixels mode, type the width and height (or tap a preset) and click Resize. The lock keeps the proportions correct.
Can I resize an image by percentage?
Yes. Switch to Percent mode and drag the slider, for example 50% halves the width and height.
Will resizing distort my image?
Not if you keep the aspect-ratio lock on. It automatically calculates the matching dimension so the picture never stretches.
Do you upload my image to resize it?
No. Resizing is done entirely in your browser and your image is never uploaded.