// 免费在线工具
将图片压缩至100KB
自动压缩任何图片至100KB以内。智能质量优化会找到满足100KB目标的最高质量。免费，无需上传，立即完成。
何时需要将图片压缩至100KB以下？
许多平台和使用场景都要求图片低于特定文件大小阈值：邮件营销工具（MailChimp、ConvertKit）建议低于1MB但会压缩嵌入图片；政府和学术表单上传常限为100KB；一些招聘门户要求个人照片低于100KB；某些CMS插件会对大图标记警告。
自动优化如何工作
与手动猜测质量设置不同，该工具采用二分搜索算法：从质量46开始，检查结果是否高于或低于100KB，然后上下调整质量并重复——共7次迭代，最终收敛到距离100KB目标约1%的范围内。这样即可自动找到仍符合限制的最高质量。
如果我的图片无法压缩至100KB怎么办？
某些非常大、复杂的图片即使在极低质量设置下仍可能超过100KB。此时，还可以使用“Resize”输入框减小图片尺寸——宽高减半可将像素数降低75%，更易达到100KB目标。
常见问题
It uses a binary-search algorithm over quality settings 1–92. The algorithm tries quality 46 first, checks if the output is above or below 100 KB, then narrows the range by half each iteration. After 7 iterations (~0.3 seconds), it converges to the highest quality setting that produces a file at or under 100 KB.
The tool converts to WebP by default, which achieves the smallest possible file size. WebP is supported by all modern browsers and produces better results than JPEG at the same file size. If you need a JPEG or PNG output, use the main Image Compressor and adjust quality manually.
Yes, in most cases. A 5 MB photo can typically be compressed to 100 KB at WebP quality 45–65, which looks acceptable for thumbnail and preview use. For larger prints or high-quality display, reducing the image dimensions (using the Resize inputs) to the actual display size and then targeting 100 KB gives better visual results at the target file size.
It depends on the image size and complexity. A 1920×1080 photograph might achieve quality 60–70 at 100 KB - visually good for web thumbnails. A 4000×3000 photo at 100 KB might be quality 30–45, showing visible artifacts. For better quality at 100 KB, first resize the image to its actual display dimensions, then apply the 100 KB target.