LibraTool logoLibraTool
⏩

免费 Video Speed Changer

Speed up or slow down a video from 0.25× to 4×, with pitch-corrected audio. Great for slow-motion and timelapse. Runs entirely in your browser.

无文件大小限制文件保持私密无需登录永久免费

将文件拖放到此处或点击浏览

MP4, WebM, MOV, AVI, Video 无文件大小限制

浏览文件

你的文件永远不会离开你的设备。所有处理都在你的浏览器中本地进行。

Speed up or slow down a video (0.25×–4×), with pitch-corrected audio. Runs entirely in your browser.

Optimize for your platform

Make a Slow-Motion VideoSpeed Up a Video / TimelapseSpeed Up a Tutorial or LectureSpeed-Ramp a Clip for SocialSlow a Video Down to Analyse It

工作原理

Speeding up or slowing down a video means re-timing both the picture and the sound. This does it with FFmpeg in your browser, keeping the audio pitch natural.

  1. 1
    FFmpeg.wasm loads once
    The WebAssembly build of FFmpeg (~30 MB) downloads on first use and is cached afterwards.
  2. 2
    You pick a speed
    From 0.25× (slow motion) to 4× (fast forward / timelapse feel). Your file stays in the browser.
  3. 3
    Video and audio are re-timed
    The video uses setpts to change frame timing; audio uses chained atempo filters that stretch time without altering pitch, so voices stay natural.
  4. 4
    You download the result
    The re-timed MP4 is offered for download and previewed in-page.

No upload, no watermark — re-time personal clips, lectures, or tutorials entirely on your device.

为什么选择我们的？

✓Completely free — no hidden costs, ever
✓No account, email, or login required
✓Files stay on your device — processing happens in your browser
✓Works on any device — phone, tablet, desktop
✓No watermarks on any output
✓Browser memory limits may apply for very large files

相关工具

📏

单位转换器

在长度、重量、温度、面积、体积等单位之间转换。

试一试
🔗

URL编码与解码

编码和解码URL及查询字符串。支持encodeURIComponent、decodeURIComponent及查询字符串解析。

试一试
🎬

视频压缩

压缩视频文件以减小体积。可选择质量、分辨率和输出格式。所有处理均在本地进行。

试一试文件保留本地
这个工具对你有帮助吗？

常见问题