Resize Image

Making an image smaller (downscaling) generally preserves quality well — you're just removing pixels. Enlarging an image (upscaling) can introduce softness or pixelation because the tool has to invent new pixel data. For best results when upscaling, avoid going more than 2× the original dimensions. This tool uses canvas-based bicubic-style rendering, which gives smooth results for most use cases.

Aspect ratio is the relationship between an image's width and height (e.g. 16:9 for widescreen). When the lock is on (default), changing one dimension automatically adjusts the other to keep the image proportional. This prevents your photo from looking stretched or squished. Turn the lock off if you deliberately want to change the proportions — for example, cropping into a square from a landscape photo.

No — never. SkyTools image tools run entirely inside your web browser using the HTML5 Canvas API. Your image file is read locally on your device and the resized result is generated locally too. Nothing is sent to any server. This means your photos stay completely private, and the tool works even without an internet connection once the page has loaded.

You can upload JPG, PNG, or WebP images. The resized image is downloaded in the same format as your original — upload a PNG and you get a PNG back, upload a JPG and you get a JPG. PNG files support transparency, so transparent areas are preserved in the resized output. If you need to change the format, use the JPG ↔ PNG Converter tool on the SkyTools homepage.