Step-by-Step Tutorial to Convert MKV to WebM Quickly

The key differences between MKV and WebM are mainly in their format, compatibility, and usage. MKV is a flexible container that can store video, audio, and subtitles in one file, making it great for high-quality videos. WebM, on the other hand, is lighter and designed for online use, so it works smoothly on web browsers.

Are you planning to convert MKV to WebM? Through this post, you will learn how to convert MKV to WebM, as we will show six different ways you can follow. So, please scroll down and continue reading.

Part 1: How to Convert MKV to WebM

1. AVAide MKV Converter

FConverting MKV to WebM can be tricky if you do not know which tool to use. For beginners, the easiest way is to use AVAide MKV Converter. This program makes the process simple and fast. You can change multiple MKV videos at once with its batch conversion feature. It also uses Intel® and NVIDIA® hardware acceleration to speed up the process. With this tool, you can get your WebM videos quickly without any hassle.

Step 1Download and install AVAide MKV Converter on your computer. It works on both Windows and Mac. Please wait for the installation to finish, then launch the converter to get started.

Step 2Import your MKV files by clicking the Add File button. You can add one or multiple MKV videos at once. The program will load the files and display them in the timeline, ready for conversion.

Step 3After uploading your videos, open the Profile menu for each clip. Go to the Video tab and select WEBM as your output format. You can also click Custom Profile to change the video resolution, bitrate, and other options. It lets you customize the video to match your needs. Once done, click Create New to save your settings.

Step 4Finally, click the Convert All button at the bottom-right corner of the screen. AVAide MKV Converter will start converting your MKV videos into WebM format. When the conversion is complete, your WebM videos are ready to play, share, or upload.

2. FFmpeg

FFmpeg can convert MKV to WebM through commands in a terminal or CMD, letting you control video and audio clarity precisely. It gives excellent results for both video and sound. The downside is that it can be tricky for beginners because you need to learn the commands.

Step 1Download and install FFmpeg on your computer. Make sure the program is set up correctly.

Step 2Open CMD (Command Prompt) on your computer and type FFmpeg to check if it is working.

Step 3Insert this command to start converting:

ffmpeg -i input.mkv -c:v libvpx-vp9 -b:v 2M -c:a libopus -b:a 128k output.webm

• -i input.mkv is your MKV file name.

• -c:v libvpx-vp9 sets the video codec to VP9 for good quality.

• -b:v 2M sets the video bitrate to 2 Mbps.

• -c:a libopus sets the audio codec to Opus.

• -b:a 128k sets audio bitrate to 128 Kbps.

• output.webm is the name of your new WebM file.

Step 4Press Enter, and FFmpeg will convert your MKV file to WebM quickly.

3. Restream

Restream is an easy online MKV to WebM converter that works right in your browser. You just upload your video and convert it, no extra settings needed, super straightforward. It also supports many file types, allowing you to convert FLV, MKV, MOV, MP4, MPEG, WMV, and AVI to WebM.

Step 1Open your browser and search for Restream - MKV to WEBM Converter, and open it.

Step 2Import your MKV file by clicking the Choose File button.

Step 3The Output option is already set as .webm; there is nothing to do anymore, so proceed to click the Convert button.

4. Convertio

Convertio is another MKV to WebM converter online that is perfect for small MKV videos. It works in your browser and supports many file types, not just videos. It is convenient and user-friendly, but it only allows videos under 100 megabytes and limits you to 10 files in 24 hours.

Step 1Open your browser and search for Restream - MKV to WEBM Converter, and open it.Run a web browser, like Chrome or Safari, head to the Convertio website, and click Choose Files to upload your MKV file.

Step 2Import your MKV file by clicking the Choose File button. In the To section, click and select WebM as the output format. Then, click Convert to start the process.

Step 3The Output option is already set as .webm; there is nothing to do anymore, so proceed to click the Convert button.Please wait a few moments. Once it finishes, click Download to save your new WebM file to your device.

5. VLC

You can also use VLC to convert MKV to WebM, besides using it to play your media files. It enables you to import different video formats and save them as WebM easily. In addition, it provides features, like removing audio, subtitles, adding filters, rotating videos, or recording screens.

Step 1If you have VLC installed on your desktop, open it.

Step 2Click the Media tab and choose Convert/Save… to open the Open Media window.

Step 3Click Add to import your MKV file, and then click Convert/Save.

Step 4In the Convert window, open the Profile drop-down and select Video – VP80 + Vorbis (Webm).

Step 5In the Destination section, click Browse and choose a folder to save your new file. After that, click Start, and VLC will convert the MKV to WebM.

6. Avidemux (Linux)

Avidemux is a lightweight video editor that works on Linux and other platforms. It can convert MKV to WebM easily. As stated, Avidemux is a video editor, so you can also cut, trim, and fine-tune videos without losing clarity. It is simple and straight to the point, perfect for beginners who want a reliable free tool to convert and lightly edit videos.

Step 1Launch Avidemux on your computer.

Step 2Go to File > Open and choose your MKV video.

Step 3In the Output Format section, select WebM from the drop-down menu.

Step 4Go to File > Save or click the Save button. Please choose a name and location for your new WebM file.

Step 5For the last step, press Save, and Avidemux will quickly convert your MKV video to WebM.

Part 2: Which Method Should You Choose

Deciding which tool to use for converting MKV to WebM depends on your needs, your skill level, and how many files you want to convert at once. Each method has its strengths and limits. Here is a clear guide to help you pick the right one.

1. AVAide MKV Converter

Best for beginners and batch conversions. Fast, easy, and lets you edit videos or set output for any device.

2. FFmpeg

It is great for advanced users and offers full control and high-quality output, but needs command-line knowledge.

3. Restream

Quick online conversion. No installation needed. Simple but limited features.

4. Convertio

Good for small files online. Easy to control, but has file size limits and daily restrictions.

5. VLC

Free and already installed on many computers. Can convert and do simple edits, but slower and less user-friendly for batch tasks.

6. Avidemux

Lightweight and simple. Works well for basic edits on Linux, but lacks speed and advanced features.

By Sylvie Hyde on Sep 12, 2025