Resize an image to exact dimensions

Resize an image to target dimensions while optionally preserving its aspect ratio.

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ToolImage Resizer
Input
Output
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Preview

How it works

The source bitmap is sampled into a destination width and height using an interpolation filter; preserving aspect ratio derives one dimension from the other. Resampling changes pixel count and cannot restore detail lost in a smaller source.

  • Explicit dimensions control output bytes while aspect preservation avoids distortion.

Worked example

Fit an image inside 800 by 600
Input
											Input: data:image/png;base64,iVBORw0KGgo=
Width: 800
Height: 600
Maintain aspect ratio: true
Output
												PNG data URL scaled to fit within an 800×600 box without stretching

When to use this

Responsive thumbnails, upload optimization, and raster exports resize images.

Edge cases

  • Upscaling interpolates pixels rather than recovering detail.
  • Nonuniform dimensions stretch circles and faces.
  • Repeated resize operations compound interpolation blur.

References