ToolMulti
Your everyday online toolkit

Batch Video Speed Adjuster

A free online tool for adjusting the speed of multiple videos in bulk. Supports 0.25x–4x speed adjustment, batch processing of multiple videos, and pure in-browser local processing.

Tool Guide

Overview

An online batch video speed adjuster that processes videos locally in your browser using FFmpeg.wasm. It supports uploading multiple video files at once and adjusting their playback speed uniformly. All processing happens locally in your browser—your videos are never uploaded to a server.

Features

- Batch processing: Upload multiple video files at once and adjust their speed in bulk with a single click

- Multiple speeds: Supports 0.25x, 0.5x, 0.75x, 1.5x, 2x, 3x, and 4x preset speeds, as well as custom values

- Common formats: Supports MP4, AVI, MOV, WebM, MKV, FLV, and other mainstream video formats

- Pure local processing: Built on FFmpeg.wasm and run locally in your browser—videos are never uploaded to a server

- Packaged download: Automatically packages the results into a ZIP file for download when processing is complete

How to Use

  1. Drag and drop or click to upload one or more video files.
  2. Select or enter the desired playback speed.
  3. Click the "Start Processing" button and wait for processing to complete.
  4. Once complete, the results are automatically packaged into a ZIP and downloaded to your device.

Use Cases

- Speeding up online courses and training videos

- Batch fast-forward/slow-motion of video footage

- Speed adjustment for short-video content

- Preprocessing footage before video editing

FAQ

Q: Which video formats are supported?

A: MP4, AVI, MOV, WebM, MKV, FLV, and other common formats.

Q: Is there a file size limit?

A: We recommend keeping individual files under 100MB; the total size is limited by your browser's memory.

Q: How fast is processing?

A: Processing speed depends on the video size and your computer's performance. Smaller videos are processed quickly.