Resize an image

Resize photographs, screenshots, graphics, and web assets to exact pixel dimensions without uploading them. Enter a target width and keep aspect ratio enabled to calculate a proportional height automatically. Disable the lock only when a specific width and height are required and stretching is acceptable.

FileGizmo shows the original dimensions and file size before processing, then displays a preview with the resized dimensions and output size. The original file format is retained, including transparency for supported PNG and WebP images. Enlargement is supported, but it cannot recreate detail that was absent from the source.

Image decoding and resampling happen inside a dedicated browser worker, keeping source files on your device and the interface responsive. Dimensions are limited to sensible positive values to avoid accidental invalid canvases. For websites, resize to the largest display size actually needed and then use image compression; reducing excess pixels usually delivers a greater performance improvement than aggressive quality reduction alone.

Width and height describe the pixel grid, not the physical print size. An image that is 1200 by 800 pixels contains the same pixel dimensions whether its metadata says 72 or 300 DPI. For a website or upload form that specifies pixels, follow the pixel requirement. For professional printing, confirm the printer’s required pixel dimensions and resolution rather than changing a DPI label alone.

The aspect-ratio lock protects proportions. Entering a new width calculates a height that preserves the relationship between the source sides. Turn it off only when the destination demands an exact rectangle and you accept stretching. If the destination needs a different shape without distortion, crop the image to that aspect ratio first, then resize the crop to the requested dimensions.

Downscaling removes pixels and is usually effective for reducing delivery weight. Upscaling creates a larger grid by estimating new pixels; it cannot reveal genuine detail that the camera never captured. Small text and faces may look softer when enlarged. Use the upscale tool when you want a dedicated enlargement workflow, and inspect the result at 100 percent before relying on it.

The output keeps the source format. PNG and WebP can retain transparency, while JPG remains opaque. A resized file can occasionally be larger than the original because encoding characteristics change, especially when a heavily optimized source is resaved. If file size is the main goal, run the resized output through the image compressor after confirming dimensions.

Common uses include preparing a hero image, shrinking screenshots for documentation, creating marketplace listing dimensions, fitting a profile picture, or matching a slide template. Keep an untouched master and create named derivatives for each destination. That makes it possible to return later without enlarging an already reduced copy.

All decoding and resampling occur in local browser memory. Very large canvases can exceed mobile limits even when the compressed file looks small on disk. A current desktop browser with free memory is the most reliable choice for high-resolution photography.

After resizing, compare the result at the size where people will actually see it. Check fine text, face detail, diagonal lines, and transparent edges, then confirm the displayed width and height match the destination requirement. Downloaded derivatives are named separately, so the full-resolution source remains available for a different crop or future larger use.