访问修改图片尺寸的网站。 上传你想要修改尺寸的JPG文件。 利用修改尺寸控制功能修改图片尺寸。 选择压缩比例（如果有）。 下载修改尺寸后的图片。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
There are tons of websites that will let you quickly upload and resize any image file, including JPEG files. Some of them allow you to resize multiple images at once. Search "resize jpeg" to find a bunch of different options. Resizing using a website is most effective while using a computer, not a mobile device. Some of the more popular sites include:  picresize.com resizeyourimage.com resizeimage.net Most resizing sites allow you to upload virtually any type of image file. Click the "Choose fil