JPGからPNGへ変換
JPEG画像をPNGに変換します。
画像とファイル
画像圧縮
画像をアップロードせずに圧縮します。
画像圧縮
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, PNG, WebP · 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 an image and choose the output format.
- Set maximum dimensions if a smaller pixel size is acceptable, and adjust quality for JPEG or WebP.
- Compress, compare the output size and appearance, then download the version you prefer.
計算式と方法
Images are decoded locally and optionally reduced to your maximum dimensions without upscaling. JPEG and WebP use the chosen quality setting; PNG is lossless. Re-encoding does not guarantee a smaller result, so compare the displayed file sizes.
使用例
A 4,000 × 3,000 image with maximum bounds of 1,200 × 1,200 becomes 1,200 × 900. A WebP export can reduce size depending on image content.
When this tool is useful
Prepare a photo for an email attachment or web page when the original camera dimensions are unnecessary. Reducing dimensions can make a larger difference than lowering quality on an image that is already small.
Common mistakes and limitations
- A lower quality setting does not guarantee a smaller file for every source.
- Re-encoding can discard metadata and does not preserve an original animation as an animation.
Practical questions about this tool (English)
Why is my compressed file larger?
The source may already be well optimized, or the selected output format may be less efficient for its content. Compare sizes and keep the original if the new version offers no benefit.
Does the quality setting affect PNG in the same way as JPEG?
No. PNG uses lossless compression for the decoded pixels. JPEG and WebP use the selected quality setting; reducing PNG dimensions changes the image rather than applying the same lossy-quality control.