Convert MKV to WebM online for HTML5 players, with audio as Opus and subtitles as WebVTT. Upload files up to 20GB and download the converted result in a few clicks.
Drag & Drop your MKV file here
MKV files, up to 20GB
Files stay private.
Automatically deleted after 24 hours.
Link
20GB upload limit.
4.8/5
Trusted for 1,827,796+ conversions
HOW IT WORKS
Three steps, no account, nothing to install.
01
Upload your MKV files
Drag in .mkv videos from recordings, exports or downloads.
02
Convert to WebM
Start the conversion. VP8, VP9 and AV1 are copied; H.264, HEVC and other video is encoded to VP9 at up to 1920 px.
03
Download the WebM
Download each WebM, or several together as one ZIP.
MKV
MKV is the open Matroska container, able to hold any codec plus many audio and subtitle tracks in one file.
WEBM
WebM is Google's open web video format with VP8, VP9 or AV1 video and Opus or Vorbis sound.
FILE FORMATS
SOURCE
Matroska started in 2002 as an open, royalty-free container. An MKV can carry almost any video and audio codec, several language tracks, text and picture subtitles, chapters and even attached fonts. That flexibility makes it the favorite for film backups and recorders, though iPhones, Safari and some TVs won't play it.
TARGET
Google launched WebM in 2010 as a royalty-free format for HTML5 video. It is a restricted form of Matroska that only allows VP8, VP9 or AV1 video and Vorbis or Opus audio. Chrome, Firefox, Edge and Android play it, screen recorders and browser tools often save it, and older devices may not.
| Feature | MKV | WEBM |
|---|---|---|
| Developed by | Matroska (open standard) | |
| File extension | .mkv | .webm |
| Usual video codec | Any: H.264, HEVC, VP9, AV1 | VP8, VP9, AV1 |
| Usual audio codec | Any: AAC, AC-3, DTS, FLAC, Opus | Opus, Vorbis |
| Subtitles | Yes, many tracks | WebVTT text |
| Best for | Movies and multi-track archives | Web video and screen recordings |
| Plays on phones and browsers | VLC, most TVs; not iPhone | Browsers and Android |
USE CASES
When a browser-friendly, royalty-free file works better than MKV.
Embed video with the HTML5 video tag
Browsers play WebM natively, while MKV isn't a web format.
Keep subtitles for a web player
SRT and ASS subtitles become WebVTT tracks web players read.
Ship video in a web app or game
Browser apps and Electron projects use WebM for royalty-free video.
Post a VP9 recording without re-encoding
MKVs that already hold VP9 or AV1 are repackaged without quality loss.
Use a background video on a website
WebM is a common choice for looping hero and background videos.
Prepare clips for Wikimedia Commons
Wikipedia's media library accepts WebM but not MKV.
Share in browser-based tools
Web whiteboards and learning tools often accept WebM uploads.
Keep multiple language tracks
Every audio track is kept as Opus.
Reduce a 4K MKV for the web
4K video is scaled to 1920 px on the longest side for faster loading.
Make Discord-friendly clips
Discord previews WebM inline.
SUPPORTED FILES
MKV files with common video and audio codecs are supported.
Repackaged into WebM without re-encoding the picture.
Encoded to VP9 at good quality, at up to 1920 px on the longest side.
Encoded to Opus with the same number of channels, up to 7.1.
Converted to WebVTT. Picture subtitles (PGS, DVD) are dropped.
Upload several MKVs and download the WebMs as a ZIP.
TROUBLESHOOTING
Most surprises come from WebM's codec rules.
01
Re-encoded video is limited to 1920 px on the longest side. VP9 or AV1 sources that are copied keep their resolution.
02
ASS subtitles become WebVTT, which keeps the text and timing but not fonts, colors or positions.
03
PGS and DVD subtitles are pictures, and WebM can only carry text subtitles.
04
VP9 encoding is slower than copying. Long H.264 or HEVC files take longer.
05
Older iOS versions have limited WebM support. Use MP4 for those devices.
06
Check that the MKV plays in VLC first. A damaged file can't be converted fully.
HandBrake, VLC and FFmpeg give you every setting once installed. dragdropdo is built for turning MKV into WEBM with sensible settings already chosen, from any device.
| What matters | dragdropdo | Desktop Video Converters |
|---|---|---|
| Nothing to install | ✓Yes. Runs in any modern browser. | ~Yes, a download. FFmpeg also needs the command line. |
| Works on phones and tablets | ✓Yes. Desktop, Android, iPhone and iPad. | ~Mostly desktop only. |
| Batch conversion | ✓Yes. Add many files and download one ZIP. | ~HandBrake has a queue; FFmpeg needs scripts. |
| Share finished files | ✓Yes. Send a unique link from the result page. | ~You upload and share the files yourself. |
| Pricing | ✓Free with daily limits. $2.99 or $6.99 passes for unlimited use, no monthly plan. | ~Free (HandBrake, VLC, FFmpeg). |
| Quality and size settings | ✓Chosen for you for WEBM, with nothing to tune. | ~Yes. Full control over codecs, bitrate and resolution. |
Other tools use different pricing, limits and workflows. This comparison describes dragdropdo's own features without assuming every other tool works the same way.
1.8M+
Files converted
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4.8
Average rating
from our users
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Files kept
Auto-delete in 24h
WHY DRAGDROPDO
Convert MKV to WEBM in your browser, with nothing to install and nothing kept after 24 hours.
Private by default
Files are encrypted in transit and deleted from our servers automatically after 24 hours.
No install required
Convert in any modern browser on Windows, Mac, Linux, Android, iPhone or iPad. No app and no sign-up wall.
Big files and batches
Upload files up to 20GB each, add several at once, and download the results one by one or as a ZIP.
Share & download
Save finished files to your device or pass them on with a share link from the result page.
MORE MKV TOOLS
MKV, or Matroska Video File, is a flexible multimedia container that supports various video, audio, and subtitle codecs. Ideal for high-definition online streaming, MKV files are widely used for storing movies, TV shows, and other video content. With its ability to hold multiple tracks and metadata, MKV is a preferred choice for media enthusiasts seeking quality and versatility.
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FAQ
Answers to common questions about dragdropdo's MKV to WEBM converter.
