MasterTool

Image Format Converter

Convert images between PNG, JPEG and WebP locally in your browser — files never leave your device. Choose a file in the panel below and download the converted copy.

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Convert your image locally

No upload or network request — files never leave your device. Animated images become a single frame and metadata (EXIF) is not preserved.

What this tool does

Convert images between PNG, JPEG and WebP locally in your browser — files never leave your device. Choose a file in the panel below and download the converted copy. Processing happens in the ImageTools panel below, not in the numeric result above. JPEG has no transparency (transparent pixels become white); animated images become a single first frame; inputs are capped at 30 MB / 40 megapixels.

How to use the Image Format Converter

  1. Enter or select target format.
  2. Enter or select quality for jpeg/webp (%).
  3. Read the calculated result; change any measurement to compare alternatives.

Formula

Decode the local image, draw it to a browser Canvas at its native size, and re-encode with canvas.toBlob(target type, quality/100) for a local download.
format
Target format
quality
Quality for JPEG/WebP (%)

Processing happens in the ImageTools panel below, not in the numeric result above. JPEG has no transparency (transparent pixels become white); animated images become a single first frame; inputs are capped at 30 MB / 40 megapixels.

Worked example

For image format converter, the following measurements illustrate the exact method: Target format: webp; Quality for JPEG/WebP (%): 85.

Inputs

  • Target formatWebP
  • Quality for JPEG/WebP (%)85

Result

  • ConversionSelect a local image in the panel below to convert it to WEBP and download it.

Results explained

Conversion
Conversion from the formula above. Processing happens in the ImageTools panel below, not in the numeric result above. JPEG has no transparency (transparent pixels become white); animated images become a single first frame; inputs are capped at 30 MB / 40 megapixels.

Frequently asked questions

WebP for the smallest web files with good browser support, JPEG for maximum compatibility with photos, and PNG when you need lossless quality or transparency. PNG ignores the quality setting because it is lossless.

JPEG cannot store transparency, so the converter composites transparent pixels onto white. Convert to PNG or WebP to keep the alpha channel.

JPEG and WebP are lossy: each re-encode discards some detail, controlled by the quality setting. PNG conversion is lossless but usually produces larger files for photos.

No. Files are decoded and re-encoded with the browser Canvas API on your device. There is no upload, no server and no network request — you can verify by processing an image while offline.

Canvas re-encoding does not copy EXIF, GPS or camera metadata into the output — a privacy benefit, but copy any metadata you need before converting.