WMV to WebM Converter
Generate the correct FFmpeg command to convert WMV video files to WebM (VP9/Opus) with your chosen quality and audio settings.
Command Builder
4 — best quality (large)
63 — smallest (low quality)
FFmpeg Command
Click "Generate Command" to build your FFmpeg command.
Two-pass: run both commands in order
Two-pass encoding first analyzes the video (pass 1), then encodes it (pass 2). The pass 1 command writes a log file (ffmpeg2pass-0.log) which pass 2 reads. Run pass 1 first, then pass 2.
Quick Reference
-c:v libvpx-vp9
VP9 video encoder (best quality for WebM)
-crf 33
Constant rate factor — quality target
-b:v 0
Required alongside -crf for VP9 VBR mode
-c:a libopus
Opus audio — standard for WebM
-vf scale=W:H
Resize video to width W and height H
Install FFmpeg
Ubuntu
sudo apt install ffmpeg
macOS
brew install ffmpeg
Windows
winget install ffmpeg
Summary
Generate the correct FFmpeg command to convert WMV video files to WebM (VP9/Opus) with your chosen quality and audio settings.
How it works
- Enter your input WMV filename and desired output filename.
- Choose a video codec — VP9 is recommended for best quality-to-size ratio.
- Set the CRF (Constant Rate Factor) — lower numbers mean higher quality and larger files.
- Select an audio codec and bitrate.
- Optionally set a target resolution or leave blank to keep the original.
- Click "Generate Command" and copy the FFmpeg command to run in your terminal.
Use cases
- Convert old WMV recordings to WebM for use on websites without a plugin.
- Prepare video files for HTML5 <video> tags that require WebM format.
- Reduce file size of WMV screencasts for sharing or uploading.
- Batch-convert a folder of WMV files to WebM using the generated command as a template.
- Convert WMV files on Linux or macOS where WMV playback support is limited.
- Prepare video assets for web projects that require open, royalty-free formats.
Frequently Asked Questions
Last updated: 2026-06-11 ·
Reviewed by Nham Vu