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Resize images to the exact dimensions you need

Set width or height while keeping the original aspect ratio by default.

On-device processing
Formats: JPG, PNG, WebPFiles: Single file

Processed entirely in your browser. The selected file is not uploaded to FileLume.

Choose a file

Tap to choose from Files or your photo library.

Supported: JPG, PNG, WebP · Outcome: Change image width and height with simple presets.

Processed entirely in your browser. The selected file is not uploaded to FileLume.

Settings

Common choices stay visible. Defaults work for most files.

Choose a supported JPG, PNG, WebP input to continue.

Helpful details before processing

Change image width or height in a browser canvas while keeping the original aspect ratio by default.

Technical details · Reviewed 2026-07-13

What this tool does

Change image width or height in a browser canvas while keeping the original aspect ratio by default.

How it works in FileLume

  • When only width is entered, height is calculated from the original aspect ratio; height-only input works the same way in reverse.
  • The browser draws the decoded image into a canvas at the requested output dimensions and exports a new copy.

Best for

  • Preparing profile, product, blog, CMS, and form images with a required pixel size.
  • Reducing oversized dimensions before compression.
  • Creating consistent dimensions for a batch or repeat workflow.

Format and quality guidance

  • Keep aspect ratio enabled when you want to avoid stretching the image.
  • Use exact width and height only when the destination truly requires both values.
  • Choose PNG/WebP when transparency matters; JPG is normally better for photos.

Trade-offs to expect

  • Upscaling creates more pixels but cannot restore detail that was not present in the source.
  • Disabling aspect ratio can stretch faces, products, logos, and text.

Limitations

  • Extremely large output dimensions can exceed browser canvas or memory limits.
  • Resizing re-encodes the image and may remove metadata.

Common errors and fixes

The image looks stretched.
Reset the settings and keep aspect ratio enabled.
The enlarged image is blurry.
Use a higher-resolution source; upscaling cannot recreate missing detail.
The output is still too large in bytes.
Run Compress Image after the dimensions are correct.

Resize Image FAQ

Can I enter only width?

Yes. With aspect ratio enabled, FileLume calculates the matching height from the source image.

Does resizing reduce file size?

Usually, when dimensions are reduced. The final byte size also depends on format, image content, and export quality.

Should I resize or crop first?

Crop first when framing matters, then resize the cropped result to the destination dimensions.

Reviewed workflow evidence

Practical workflow examples

A square avatar for a profile or directory.

Resize or crop to a square 300×300 output, then check that the important subject remains centered.

Constraint: Forcing non-square images to 300×300 without cropping can distort them.

Reviewed 2026-07-10

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