图像压缩
本地压缩图像，无需上传。
图像与文件
JPG转PNG
将JPEG图像转换为PNG。
JPG转PNG
由 UtilBrix 提供支持将图片拖到此处
从设备中选择文件
JPG / JPEG · 每个文件 25 MB · 总计 50 MB · 最高 4000 万像素
详细方法和示例目前以英语提供。
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.
公式与方法
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.
实际示例
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.