工作原理
上传图片，设置宽高并导出。Canvas 本地渲染。
为社交媒体裁剪和缩放图片。
JPG, PNG, and WebP. Max 20 files per batch.
上传图片，设置宽高并导出。Canvas 本地渲染。
Conversions run in your tab with JavaScript — no desktop app required.
Files stay on your device during processing. We do not receive your uploads.
Heavy codecs and AI models run locally via Web Workers and WASM (FFmpeg.wasm, Transformers.js).
上传图片，设置宽高并导出。Canvas 本地渲染。
放大超过原分辨率可能发虚。EXIF 可能被移除。 处理 100% 在浏览器内离线完成——文件不会离开您的设备。
Yes. This tool is free convert online with no signup. Processing stays in your browser — no uploads.
You control quality settings. Choose higher quality for no quality loss when converting online.
Every conversion runs inside your browser tab using JavaScript and Web Workers. There is no background server queue and no account is required for core tools.
Your files are never uploaded to FreeConvertKit for processing. Originals, previews, and exports stay on your device unless you choose to download or share them yourself.
When codecs or AI models are needed, WebAssembly modules such as FFmpeg.wasm and Transformers.js execute locally — giving you desktop-class power with absolute file privacy.