Resize Image

Resizing changes the pixel dimensions of an image, while compressing changes how the file is encoded at the same dimensions. Resizing usually reduces file size a lot because fewer pixels need to be stored. For the smallest possible file, resize first and then compress.

Only if you turn off the aspect-ratio lock and enter a width/height that does not match the original proportions. With the lock enabled, images scale proportionally and never stretch.

In locked mode, each image is scaled to fit inside the width and height you set while preserving its own proportions. This is the safest option for batches where images have different aspect ratios.

Yes. The percentage mode supports upscaling, and you can type target dimensions larger than the original. Enlarging cannot invent detail, so results will look softer than the source; keep the increase modest.

Match the largest size the image will actually be displayed at. Common targets include 1920px wide for full-screen hero images, 1200px for blog headers, 800px for article images, and 400px for thumbnails. Serving larger images than needed wastes bandwidth.

Yes. PNG, WebP, and AVIF transparency is preserved. If you choose JPEG output, transparency is flattened onto a white background because JPEG does not support alpha.