Free MP4 to WebM converter
MP4 to WebM Converter
Video converter
Bulk MP4 to WebM
Drag MP4 files here
Or choose videos from your device and convert them locally in this tab.
Nothing uploads. Video encoding runs locally and may take about the length of each clip.
Use the MP4 to WebM converter in 3 steps
01
Drag and drop MP4 videos
Choose one or more .mp4 files from your device or drag them into the queue. Unsupported files are skipped so mixed batches are easier to clean up.
02
Convert with Mediabunny
Select Convert All to let Mediabunny transcode the primary MP4 video track into VP8 or VP9 WebM directly in the browser.
03
Download one ZIP of WebM files
When conversion finishes, successful WebM files are packaged into one ZIP archive so you can save the whole batch in one click.
Frequently Asked Questions
How do I convert MP4 to WebM online?
Add one or more MP4 files, run Convert All, and let the browser process the video locally with Mediabunny. When conversion finishes, download the successful WebM files together in one ZIP archive.
Does this MP4 to WebM converter upload my videos?
No. Conversion runs in your browser, so selected MP4 files stay on your device instead of being uploaded to Toolsetta servers for processing.
Which browsers can convert MP4 to WebM locally?
A recent browser with the media APIs needed for local decoding and encoding is required. Chromium-based browsers currently have the best support for VP8 or VP9 WebM output.
Will the converted WebM include audio?
Audio is included when the browser can decode the MP4 audio track and encode Opus for the WebM output. If that support is unavailable, the converter still exports the WebM video track and marks the item as audio skipped.
Can I convert multiple MP4 files at once?
Yes. The converter supports batch MP4 to WebM conversion. Add multiple MP4 videos, convert the queue, and download all successful WebM outputs in a single ZIP file.
Does converting MP4 to WebM reduce quality?
WebM video is re-encoded, so output is not identical to the original MP4. The converter chooses a browser-friendly bitrate for practical web playback while keeping the workflow fully local.
Why use WebM instead of MP4?
WebM is useful for open web video workflows, browser playback, web app assets, demos, and environments that prefer VP8 or VP9 video in a WebM container.
What happens if one MP4 fails during conversion?
The queue shows file-level errors so you can identify the problem item. Successful conversions are still packaged for download, which is useful when only part of a batch needs to be retried.