Compress Image Online
無料のオンライン画像圧縮ツール。JPG・PNG・WebP・GIFを最大90%圧縮、画質を維持。アップロード不要・登録不要。
ツールを開くimage
画像形式変換オンライン — PNG・JPG・WebP など相互変換
無料のオンライン画像形式変換ツール。PNG・JPG・WebP・GIF・BMP・SVG・AVIF などの形式を相互変換、品質調整可能。
画像をドロップまたはクリックしてアップロード
または
ファイルを選択使い方
- 1 Upload an image in any common format.
- 2 Pick the output format and adjust quality if needed.
- 3 Click download to save the converted image.
機能
Export as PNG, JPG, WebP, AVIF, BMP, or ICO
Accepts PNG, JPG, WebP, GIF, BMP, SVG, ICO, and AVIF input
Live preview with file size comparison
Adjustable quality for lossy formats
よくある質問
Which formats can I convert to?
PNG, JPG, WebP, AVIF, BMP, and ICO. Output formats your browser cannot encode are disabled automatically.
Why is the exported ICO smaller than my image?
ICO files are traditionally limited to 256×256 pixels. Larger images are scaled down proportionally, and the final size is shown in the result panel.
Why does the converted JPG lose transparency?
JPG does not support transparency, so transparent areas are filled with white. Choose PNG or WebP to keep transparency.
What happens to animated GIFs?
Only the first frame is converted — the result is a static image.
Are my images uploaded to a server?
No. Conversion happens entirely in your browser; images never leave your device.