Image Converter

Convert a 1200×800 image/png image to image/webp.

How it works

• Decode the local file with the browser's own image decoder (createImageBitmap).
• Draw it at its original size onto a canvas.
• Encode the canvas as image/webp at quality 80.
• Report the new byte size and offer the result for download.

• The file never leaves the browser: no upload, no server, no retention.
• AVIF output is best-effort and depends on the browser's encoder.

Methodology

1. Decode the selected file with the browser's native image decoder; reject an undecodable or oversized file with a named finding.
2. Paint the decoded bitmap at its original dimensions onto a canvas.
3. Encode the canvas with the requested MIME type; PNG is lossless (no quality), the others use the requested quality.
4. Report the output MIME, byte size and dimensions, and offer the encoded blob as a download.

Usage

1. Choose or drop a PNG, JPEG, WebP or AVIF image.
2. Select the output format and, for lossy formats, a quality value.
3. Run the conversion to see the new byte size, then download the result.

Examples

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

PNG to WebP at quality 80

{
  "sourceMime": "image/png",
  "sourceWidth": 1200,
  "sourceHeight": 800,
  "outputType": "image/webp",
  "quality": 80
}

JPEG to PNG (lossless)

{
  "sourceMime": "image/jpeg",
  "sourceWidth": 640,
  "sourceHeight": 480,
  "outputType": "image/png",
  "quality": 100
}

Limitations

Local-only conversion

The converter runs entirely in your browser using the platform image decoder, a canvas and the encoder. Your file is never sent to a server, and the result blob stays on your device until you download it.

Because the encode happens locally, the available output formats are exactly those your browser supports; the tool probes the result rather than assuming a format works.