Image Resizer

Resize the image to 100×50 pixels.

How it works

• Decode the local file with the browser's image decoder.
• Compute the target as 100×50 (aspect ratio locked, rounded once).
• Draw the decoded bitmap into a canvas of the target size.
• Encode the result as image/png at quality lossless.

• The file never leaves the browser.

Methodology

1. Resolve the target dimensions deterministically: a percentage scales both axes; a single axis with the lock derives the other by rounding once; two axes are used verbatim.
2. Clamp every dimension into the safe 1–8192 pixel range and refuse a target beyond the pixel cap.
3. Draw the decoded bitmap into a canvas of the target size and encode it in the source format (or PNG).

Usage

1. Choose or drop an image.
2. Enter a target width and/or height, or a percentage; keep the aspect-ratio lock on to avoid distortion.
3. Run the resize and download the result.

Examples

These are examples, not current values: they use fixed inputs, while the interactive tool computes live results in your browser.

Halve the width, aspect locked

{
  "sourceMime": "image/png",
  "sourceWidth": 200,
  "sourceHeight": 100,
  "outputType": "image/png",
  "width": 100,
  "height": null,
  "percent": null,
  "keepAspect": true
}

Scale to 50%

{
  "sourceMime": "image/jpeg",
  "sourceWidth": 800,
  "sourceHeight": 600,
  "outputType": "image/jpeg",
  "width": null,
  "height": null,
  "percent": 50,
  "keepAspect": true
}

Limitations

Deterministic sizing

The target dimensions are computed by a small pure function so the same input always yields the same size: percentage scaling, single-axis derivation with a single rounding step, or two explicit axes.

Every dimension is clamped to 1–8192 pixels and a target beyond the 40-million-pixel cap is refused with a named finding rather than attempted.