当您需要无损格式用于编辑、图形或透明度时，可将 JPG（JPEG）图片转换为 PNG。PNG 非常适合 Logo、截图和边缘清晰的图片。
一切都在您的设备本地完成 — 您的图片绝不会被上传到服务器。
如何使用此工具
添加 JPG
将您的 JPG 拖放到工具上，或点击选择文件。
PNG 已默认选中
输出已设置为无损 PNG，因此不会进行任何重新压缩。
预览效果
并排比较原始图片和转换后的 PNG。
下载
下载您高质量的无损 PNG 文件。
本节目前仅提供英文版本。
What this conversion can and cannot do
Converting JPEG to PNG is lossless in the sense that no further quality is lost: every pixel of the JPEG is stored exactly. What it cannot do is recover what the JPEG already threw away. The blockiness and ringing in a heavily compressed JPEG are part of the image now, and a PNG will preserve them faithfully.
This is the most common misconception in image conversion, so it is worth stating plainly: **a JPEG converted to PNG is a large file with JPEG quality.** It does not become a better image.
The one good reason to do it
Editing. If you need to open the image in an editor, cut something out of it, or composite it with other artwork, PNG is the right working format — repeated saves will not degrade it further the way repeated JPEG saves would. Convert to PNG, do the work, then export back to an efficient delivery format at the end.
If what you actually want is transparency
JPEG cannot store transparency, so converting to PNG does not create any — the background pixels are whatever colour they were, and you have to remove them yourself. Tools that claim to add transparency while converting are really running a background-removal step, which is a different operation with its own accuracy limits.
常见问题
为什么要将 JPG 转换为 PNG？
PNG 是无损格式且支持透明度，非常适合 Logo、截图以及需要无质量损失编辑的图片。
转换是无损的吗？
是的 — 输出编码为无损 PNG，因此转换过程不会损失任何额外的质量。
PNG 会比 JPG 更大吗？
通常会的，因为 PNG 是无损而 JPG 是有损的。这种权衡是可以预期的 — 您用体积换取质量和透明度。