画像フォーマット変換

This tool turns JPG, PNG, WebP and other formats into JPG, PNG or WebP, with a quality slider for the lossy outputs. Pick an image, choose the target format, and download the result.

Converting format is a constant need: turning a WebP you saved into a JPG an app will accept, flattening a PNG to JPG to cut its size, or moving photos to WebP to shave bandwidth on a website.

The conversion runs entirely in your browser, so your images never leave your device.

It reads any image your browser can open and exports to the three main web formats using the Canvas API, so it is instant. JPG flattens transparency onto a white background, while PNG and WebP both keep transparency intact.

Choosing well depends on the image: JPG suits photographs, PNG suits graphics, screenshots and anything with transparency or sharp edges, and WebP usually gives the smallest file at a similar quality, which is why it is popular for the web.

For the lossy formats (JPG and WebP), the quality slider trades detail against file size. PNG is lossless, so it keeps every pixel but produces larger files for photos.