Last updated 23 August 2026
Locked vs free aspect ratio
With the ratio locked, changing the width automatically works out the matching height (and vice versa), so the image keeps its original proportions. Unlock it if you specifically need a different shape — a square crop-to-fit for a profile photo, for instance — though the image will look stretched if the new ratio is very different from the original.
Making an image smaller is safe; making it bigger is not
Scaling down discards pixels, and the result stays sharp because all the detail you are keeping was really there. Scaling up has to invent pixels that were never captured. The software guesses from the neighbouring ones, and the result looks softer or blockier the further you push it.
So a 4000-pixel photo resized to 800 will look excellent. An 800-pixel image blown up to 4000 will not gain detail no matter which tool you use — it will only get larger and blurrier. If you need a bigger version, going back to the original file always beats enlarging a small copy.
Keep the aspect ratio locked unless you have a reason not to. Changing width and height independently stretches faces and text in a way that is immediately obvious even to people who could not say why the picture looks wrong.
Related guide: Social media image sizes, and why they keep changing
Common questions
What does locking the aspect ratio do?
It keeps width and height proportional to the original, so changing one automatically updates the other and the image can't be stretched or squashed. Turn it off if you deliberately want a different shape.
Can I make an image bigger than the original?
Yes, but enlarging beyond the original size will look softer or blurrier, since there's no extra real detail to add — the browser is estimating new pixels, not recovering lost ones.
Is my image uploaded anywhere?
No. Resizing happens on an HTML canvas in your own browser. The image never leaves your device.