Queue MP4 videos
Choose one or more non-empty .mp4 files up to 100 MB each. Every queued row keeps its own playable source preview.
Free online MP4 to WebM converter
Create new WebM copies from MP4 videos.
Queue MP4 videos, encode a fresh VP9 WebM from the first video stream and optional first audio stream, then preview and download every result.
- Files not stored
- Queue MP4 files
- 100 MB each
Processed by our self-hosted conversion engine
Supported files
MP4 in. WEBM out.
MP4WEBM
Add MP4 video files up to 100 MB each. Fileverses creates a new WEBM result with this route’s documented conversion profile; review the completed download before using it elsewhere.
How it works
One queue. A new WEBM file.
Create WebM copies
Start the queue to have FFmpeg use the first video stream and optional first audio stream, then encode a new WebM with VP9 video and Opus audio when available.
Preview and download
Inspect each completed WebM in the queue, then download that separately named .webm result.
Limits and quality
A new WEBM file, with source-specific trade-offs.
The profile maps the first video stream and, if present, the first audio stream, then removes source metadata. It does not preserve subtitles, attachments, chapters, alternate streams, or the original codecs.
Convert MP4 nowMP4 sources only
This route accepts non-empty .mp4 files up to 100 MB each. The selected video must also be readable by the host FFmpeg installation.
First streams only
The profile maps the first video stream and, if present, the first audio stream, then removes source metadata. It does not preserve subtitles, attachments, chapters, alternate streams, or the original codecs.
New VP9 WebM encoding
Each result is a fresh WebM using VP9 video at the route's fixed quality setting and Opus audio when source audio exists. There are no trim, resize, codec, bitrate, quality, or lossless controls, and output size, visual equivalence, playback compatibility, or audio presence is not guaranteed.
MP4 to WEBM FAQ
Questions, answered.
What MP4 files can I convert to WebM?+−
This converter accepts non-empty .mp4 videos up to 100 MB each. The host FFmpeg installation must also be able to read the selected source.
What does the downloaded WebM contain?+−
A successful conversion creates a new WebM with VP9 video from the first video stream. If the MP4 has a readable first audio stream, it also contains newly encoded Opus audio.
Does MP4 to WebM keep every stream or metadata?+−
No. The profile uses only the first video stream and optional first audio stream, and removes source metadata. It does not promise subtitles, attachments, chapters, alternate tracks, original codecs, or metadata preservation.
Can I convert several MP4 videos at once?+−
Yes. Add multiple supported MP4 files to the queue. The browser submits real conversions sequentially, and every successful row receives its own WebM preview and download button.
Will the WebM be smaller or look identical to my MP4?+−
Not necessarily. WebM is newly encoded with this route's fixed VP9 and optional Opus settings. File size, detail, and playback behavior vary, so inspect the result and test it in the destination.
Can I trim the MP4 or choose codecs and bitrate?+−
No. This route has no trimming, stream-selection, resizing, codec, bitrate, or quality controls. It uses its fixed VP9 and optional Opus profile.
Will every browser or application support the result?+−
No. The result uses a WebM container with VP9 video and optional Opus audio, but receiver and application support still varies. Test the downloaded file in your required destination.
Are files kept after conversion?+−
Each source and output exists in a temporary server directory only while its conversion runs. The directory is removed whether the job succeeds or fails.