免费将 PNG 转换为 JPG（JPEG）。JPEG 在任何地方都受支持 — 包括电子邮件、打印流程和照片库 — 而且对于照片，它生成的文件比 PNG 小得多。
您的图片在浏览器中本地处理，绝不会被上传。
如何使用此工具
添加 PNG
拖放您的 PNG 或点击选择文件。
JPG 已默认选中
输出已设置为 80% 质量的 JPG — 这是照片的可靠默认值。
对比
在下载前检查效果。
下载
下载您的 JPG。
本节目前仅提供英文版本。
The single biggest size reduction available
PNG stores every pixel exactly; JPEG throws away detail the eye is unlikely to miss. Converting a photograph from PNG to JPEG routinely cuts the file by 80–95%, which is why almost no photograph on the web is a PNG today.
The catch is the same as the benefit: the discarded detail is gone. This is a one-way conversion unless you kept the original.
The transparency problem
JPEG has no alpha channel. Where a PNG has transparent pixels, the conversion has to put something there — usually white, sometimes black. If your image has transparency, it will not survive this conversion; flatten it onto a chosen background first, or use WebP instead, which keeps transparency and is still much smaller than PNG.
When PNG to JPEG is the wrong move
- Screenshots and text — JPEG artefacts land exactly on letter edges, where they are most visible.
- Line art, logos and icons — sharp edges and flat colour are what JPEG handles worst.
- Anything with transparency.
- Anything you will edit repeatedly — each save re-compresses.
常见问题
将 PNG 转换为 JPG 会损失质量吗？
JPEG 是有损格式，因此会损失一些质量。对于照片，在高品质设置下几乎察觉不到。带有文字的平面图形最好保留为 PNG。
JPG 支持透明度吗？
不 — JPG 不支持透明度。转换过程中，透明区域会填充为白色。
这是免费的吗？
是的，完全免费，没有任何限制。