Compress Image
Reduce image file size without noticeable quality loss. Free, fast, 100% in your browser.
How to use / 使用步骤
- Drag your images into the upload area, or click to select files (batch supported).把图片拖进上传区，或点击选择文件（支持批量）。
- Drag the Quality slider and watch the file size change — lower means smaller.拖动「质量」滑块预览体积变化，数值越低文件越小。
- Click download when you're happy; multiple images can be saved together as a ZIP.满意后点击下载，多张图可一键打包 ZIP。
About Compress Image / 关于本工具
Image compression reduces the number of bytes a photo takes up so it loads faster on websites, sends more easily by email, and uses less storage. This tool re-encodes your picture with the JPEG (or WebP) algorithm at a quality level you choose. JPEG is "lossy": it discards fine detail the human eye barely notices — subtle gradients in a blue sky, tiny texture in shadows — and keeps the structure that matters. A photo straight from a phone is often 4–8 MB; at quality 70–80 it can drop to a few hundred kilobytes while still looking sharp on screen.
图片压缩就是减少一张照片占用的字节数，让它在网页上加载更快、发邮件更顺畅、占用更少存储。本工具用你选定的质量等级，以 JPEG（或 WebP）算法重新编码图片。JPEG 属于"有损"压缩：它丢弃人眼几乎察觉不到的细节——蓝天里细微的渐变、阴影中的微小纹理——而保留关键结构。手机直出照片常有 4–8 MB，在质量 70–80 时往往能降到几百 KB，屏幕上看依旧清晰。
How to pick a quality level / 怎么选质量
For photos shared online, quality 70–80 is the sweet spot — large size savings with no obvious loss. Go to 85–90 only when you need print-grade fidelity. Below 50 you'll start to see blocky "artifacts" around edges and text. Because everything runs on your own device with the HTML5 Canvas API, your originals are never uploaded, so you can compress sensitive photos privately and instantly.
用于网络分享时，质量 70–80 是甜区——体积大幅下降且看不出损失。只有需要接近印刷品质时才用 85–90。低于 50 会在边缘和文字周围出现块状"伪影"。由于全部基于 HTML5 Canvas 在你自己的设备上完成，原图绝不上传，敏感照片也能私密、即时地压缩。