How it works
Complete the job in three clear steps
- Choose a video file from your device.
- Set the timing or output options and create a speed-adjusted MP4.
- Preview and download the result before closing the page.
Private Lucaden media tool
Change Video Speed
Create a slower or faster MP4 with synchronized audio for common speed multipliers.
Free to use Your media stays on this device; the FFmpeg WebAssembly runtime downloads when needed.
Loading tool workspace…
Important
Check the result before relying on it
Keep an untouched copy of important source files. Browser processing depends on available device memory, and you should inspect every downloaded result before deleting the original.
Practical details
What this Lucaden tool does
Lucaden changes video presentation timestamps and applies a matching audio tempo filter for 0.5× to 2× playback. The result is re-encoded into a standard MP4.
Lucaden writes the source into FFmpeg's temporary in-browser file system, creates the output, then removes both temporary files. The source media is not uploaded to Lucaden.
Included capabilities
- 0.5×, 0.75×, 1.25×, 1.5×, and 2×
- Synchronized audio tempo
- H.264 and AAC output
- Local playback preview
Useful for
- Create a time-lapse
- Slow a demonstration
- Speed up tutorials
- Adjust rehearsal videos
Questions
About this tool
Will pitch change?
The audio tempo filter aims to preserve pitch within the supported speed range.
Can I use more extreme speeds?
This focused browser route limits presets to a practical range for audio synchronization and device performance.
Open-source foundations
Built transparently
Lucaden documents its standards sources, architectural references, and permissive runtime dependencies while keeping this workspace consistent with the Lucaden interface.