What image formats can I convert between?

The converter supports JPEG, PNG, and WebP as output formats. It can read any format your browser supports as input, which includes JPEG, PNG, WebP, GIF, BMP, and SVG. This covers the vast majority of web image formats.

Does converting to PNG increase file size?

Usually yes. PNG is a lossless format, so it preserves every pixel exactly — which means files are typically larger than JPEG or WebP equivalents. If file size matters, use JPEG (for photos) or WebP (for the best compression-to-quality ratio on modern browsers).

What is the quality slider for?

The quality slider controls lossy compression for JPEG and WebP output. At 100%, the output is near-lossless (large file). At 70–80%, quality is excellent and files are significantly smaller. Below 60%, you may notice compression artifacts. PNG ignores the quality slider because it's always lossless.

What happens to transparency when converting to JPEG?

JPEG does not support transparency. When converting a PNG with a transparent background to JPEG, the transparent areas are filled with white. If you need to preserve transparency, convert to PNG or WebP instead — both support alpha channels.

Is my image uploaded to a server?

No. All conversion happens in your browser using the HTML5 Canvas API. Your image is never sent to any server. The converted result is generated locally and downloaded directly from your browser.

画像フォーマット変換

JPEG、PNG、WebP形式間で画像を瞬時に変換。品質を調整してファイルサイズを比較し、結果をダウンロードできます。

🖼️

画像をここにドロップまたはクリックしてアップロード

JPEG、PNG、WebP、GIF、BMPに対応

使い方

JPEG、PNG、WebP形式間で画像を瞬時に変換。品質を調整してファイルサイズを比較し、結果をダウンロードできます。

1Drop your image onto the upload area or click to browse and select an image file.
2Choose the output format: JPEG, PNG, or WebP.
3For JPEG or WebP, drag the quality slider to balance file size vs. image quality (80% is a good default).
4Click Convert. Preview the result and see the new file size vs. original.
5Click Download to save the converted image to your device.

主な機能

Three output formats — JPEG, PNG, WebP, covering all modern web image needs
Quality control — adjustable compression for JPEG and WebP output
File size comparison — see exactly how much space you saved
Drag-and-drop interface — no clicking through file dialogs
100% browser-based — images never leave your device

よくある質問

詳しく読む

Image Format Converter — JPEG vs PNG vs WebP: Which to Use?