画像圧縮
画像をアップロードせずに圧縮します。
画像とファイル
JPGからPNGへ変換
JPEG画像をPNGに変換します。
JPGからPNGへ変換
UtilBrix が提供画像をここにドロップ
端末からファイルを選択
JPG / JPEG · 1 ファイル 25 MB・合計 50 MB · 最大 4000 万画素
詳しい方法と使用例は英語で提供しています。
Step-by-step instructions (English)
- Select the JPEG image you want to convert.
- Run the conversion and inspect the resulting image and dimensions.
- Download the PNG while retaining the JPEG if file size matters.
計算式と方法
The browser decodes JPEG pixels and encodes a PNG image. PNG uses lossless compression for the decoded pixels, but converting cannot recover detail already lost in the JPEG. Files are processed locally.
使用例
A 1,200 × 800 JPEG converts to a 1,200 × 800 PNG. The PNG can be larger because it stores the decoded pixels without additional lossy compression.
When this tool is useful
Create a PNG version when a workflow requires that file type or you want to avoid another lossy JPEG save during later editing. The conversion changes the container and encoding, not the amount of detail in the original photograph.
Common mistakes and limitations
- Converting a JPEG to PNG cannot restore image detail already lost in JPEG compression.
- PNG output is often larger for photographs, so conversion is not automatically a compression technique.
Practical questions about this tool (English)
Will the converted PNG have a transparent background?
No. JPEG does not contain an alpha channel, and conversion does not remove the background. The original image background remains visible.
Will the pixel dimensions change?
Format conversion preserves the decoded dimensions. Use Image Resizer separately when the receiving system also requires a different width or height.