mp4
Most compatible output
Use MP4 when the result needs to play on phones, messaging apps, presentations, or social networks.
Fast, private video editing
Video Speed Changer
Change the playback speed of your videos. Speed up to 10x or slow down to 0.1x — perfect for timelapses, slow motion, or reviewing footage faster.
Files stay on your device MediaBunny Web Worker processing Free to use
Choose a speed in one click
Use 0.5x for slow motion, 2x–4x for review, or 10x for a quick timelapse. Keep audio on when you want speech and music to follow the video.
Step 1 · Add videos
Upload videos to change speed
Drop one or more files here. Batch processing keeps the same settings for every file.
Processed locally in your browser
Drop videos here or click to browse
MP4, MOV, WebM, MKV, AVI — up to 2GB
You might also need
Video Trimmer
Cut videos to a precise time range in your browser. Fast mode prioritizes speed, while Precise mode supports frame-accurate trimming.
Video Converter
Convert MP4, WebM, MKV, and MOV videos online in your browser. Choose a format and codec, process files locally, and download the result without uploading your video.
Compress Video
Compress MP4, WebM, MOV, MKV, AVI, and other videos online in your browser. Reduce file size privately with platform presets for YouTube, TikTok, Instagram, WhatsApp, and Discord.
Video Muter
Remove audio from video — create silent videos instantly. Mute one or batch-process multiple videos, all in your browser.
Video speed changer guide
Supported video formats
Change the playback speed of common video files without installing software. The source file is decoded in your browser and the result is exported as MP4 or WebM.
webm
Web-friendly output
Use WebM for modern browsers and websites when a compact file is more important than legacy compatibility.
mov
Apple video container
MOV files can be added when the browser can decode their internal video and audio codecs.
mkv
Flexible input container
MKV input is useful for recordings and archives; choose MP4 or WebM for the most portable result.
avi
Legacy video input
AVI input is accepted when its codec is available to the browser and MediaBunny.
m4v
MPEG-4 video input
M4V files from phones and editing apps can be slowed down or sped up like MP4 files.
How to change video speed
The workflow is designed for quick edits and repeatable batch processing.
- 01
Add your video
Drag a video into the upload area or choose it from your device. Multiple files can be added at once.
- 02
Pick a speed
Choose a preset from 0.25x to 10x or move the slider for a custom speed between 0.1x and 10x.
- 03
Set audio and quality
Keep or remove audio, preserve the original pitch when needed, and select an output quality and format.
- 04
Process and download
Start the local conversion, preview each result, then download one file or a ZIP of the batch.
Common ways to use a video speed changer
Speed adjustment is useful for both creative edits and everyday productivity.
Create slow motion
Use 0.25x–0.75x to study movement, highlight a moment, or make a short clip feel more cinematic.
Make a timelapse
Use 4x–10x to shorten long recordings, screen captures, talks, or behind-the-scenes footage.
Review lessons faster
Speed up lectures, webinars, and tutorials while keeping the audio track when you want to save time.
Prepare social clips
Create punchier short-form videos or make a clip fit a platform’s duration limit before uploading.
Your videos stay on your device
This page uses the File API, Web Workers, WebCodecs, and MediaBunny to process files locally. The source video and generated result are not uploaded to MediaKit servers. Object URLs and worker memory are released when you clear the task or close the page.
FAQ
Video speed changer FAQ
Are my videos uploaded?
No. Speed adjustment runs in your browser through a local MediaBunny Worker. The selected files are not sent to MediaKit servers.
Which video formats are supported?
Common MP4, M4V, MOV, WebM, MKV, AVI, WMV, FLV, 3GP, MTS, M2TS, TS, OGV, DIVX, and XVID files can be selected. Actual support depends on the codecs inside the container and your browser.
How do I keep voices from sounding high or low?
Enable Keep Audio and Preserve original pitch. This uses time-stretch processing so speech and music remain more natural, although it takes longer than the fast mode.
Does changing speed reduce video quality?
The video is re-encoded because its timestamps and frames need to change. Choose High or Max quality for detailed footage and preview the result before sharing.
How large can a video be?
The current per-file limit is 2GB. Large videos need more available memory and may take longer on phones or older computers.
Can I change video speed on a phone?
Yes, on a modern mobile browser. Keep the page open during processing; shorter clips and a lower quality preset are better for devices with limited memory.
Learn more