Image Resizer & Scaler

It depends on the “Resize behaviour” setting. “Fit inside box” keeps the original ratio and scales the picture down until it fits, “Fill exactly” stretches the image to the requested width and height, and “Cover box” fills the frame completely and crops whatever does not fit.

The preset buttons cover the most common targets: Instagram Post 1080×1080, Instagram Story 1080×1920, Facebook Cover 1200×630, YouTube Thumbnail 1280×720, Twitter/X Post 1600×900, HD 1920×1080, 4K 3840×2160 and LinkedIn Banner 1587×355 pixels. Pressing a preset always produces exactly those pixels — the picture is fitted to the target size.

You can, but enlarging cannot create detail that was never captured. Scaling up beyond roughly 150% of the original size usually looks soft, while scaling down almost always improves sharpness and file size.

Files up to 30 MB are accepted and the output is capped at about 40 megapixels, which is more than enough for print work and far beyond any social media requirement.