MP4 to MKV: Change Format for Quality, Audio & Subtitles

MP4 is one of the most common video formats, known for its small size and wide support. MKV, on the other hand, is popular for keeping high quality and handling multiple audio and subtitle tracks. Wanna know how to convert MP4 to MKV? This write-up will show you step by step. Scroll down and find the best way that works for you!

Part 1: How to Convert MP4 to MKV on Windows/Mac (Step-by-Step)

1. AVAide MP4 Converter

For Windows and Mac users, changing MP4 to MKV can be simple with AVAide MP4 Converter. It supports bulk conversion, so you can convert many files at once without repeating the same task. Another best thing about it is that it keeps high clarity during the whole process. You can also fine-tune settings like resolution, bitrate, and frame rate to fit your needs. On top of all, it is easy to use, recommended for first-time users.

Step 1Download and install AVAide MP4 Converter for free on your Windows or Mac.

Step 2Once it opens, click the Add Files button to load your MP4 videos. You can also pick and place the files straight into the program for quicker importing.

Step 3Hit the Format drop-down menu at the top right. From the list of video formats, pick MKV. You can keep the original resolution by choosing Same as Source. If you want better clarity, click the Custom Profile button and set the codec to XVID or HEVC with FLAC lossless audio. It helps improve the video and sound output.

Step 4Go back to the main screen and select where you want to save your MKV file by setting the storage path. After that, click Convert All to start the conversion. AVAide MP4 Converter works fast and will keep your video in good clarity.

Other options AVAide MP4 Converter offers: AVAide MP4 Converter offers editing features that let you cut, merge, crop, and rotate your videos. You can trim unwanted parts and keep only the clips you need. It also allows you to customize the output by adding filters, effects, text, or image watermarks.

2. VLC

VLC is not only a media player but also a video converter. If you want to convert MP4 to MKV format, VLC gives you a simple way to do it without an extra program. You can even make profiles, fine-tune codecs, and control output settings. It works on both Windows and Mac, making it a handy program for quick video conversions.

Step 1Open VLC and click on Media, then choose Convert/Save. Next, hit the Add button and pick the MP4 file you want to turn into MKV.

Step 2Click Convert in the dialog box that pops up. Next, press the Wrench button next to Profile to make a new profile.

Step 3Go to the Encapsulation tab and choose MKV as the format, then give your profile a name.

Step 4Click Browse and pick where you want to save the MKV file, then type in a name for it.

After that, click Start to initiate the conversion and wait until VLC finishes the process.

Other options VLC offers: Play DVDs, stream online videos, capture screens, fix corrupted files, record live streams, and convert audio formats, too.

Part 2: How to Convert MP4 to MKV Without Installation

1. CloudConvert

Changing MP4 to MKV without installing a program is possible, and CloudConvert makes this easy. It is an online converter that supports over 200 formats. You can control video resolution, clarity, and file size. This MP4 to MKV converter online is safe, ISO 27001 certified, and protects your data. Since it runs in the browser, you only need the internet to complete the task.

Step 1Go to CloudConvert - MP4 to MKV Converter's official website.

Step 2Click Select File and upload your MP4 file.

Step 3Once your video is loaded, MKV will automatically appear in the Convert to option.

Step 4Finally, click the Convert button, and download your converted file once finished.

Other options CloudConvert offers: Convert audio, documents, spreadsheets, presentations, and images.

2. FreeConvert

Want a free way to switch MP4 to MKV online? FreeConvert gives you that. It is an MP4 to MKV converter free that works on any web browser and does not need program downloads. The site uses SSL encryption for safety, and your files are deleted after a few hours, which keeps everything private.

Step 1Still on your browser, open FreeConvert - MP4 to MKV Converter.

Step 2Upload your MP4 file by clicking the Choose Files button.

Step 3MKV is automatically selected as the Output once your video is loaded.

Step 4You are good to click the Convert button, and please wait for the conversion process to finish.

Other options FreeConvert offers: Advanced settings for video codec, resize video, frame rate, rotate or flip video, subtitles upload, audio codec changes, adjust volume, fade effects, trim video, crop video, and remove audio.

3. VEED.IO

Some converters do more than just switch formats. VEED.IO is one of them. Besides being an MP4 to MKV file converter, it also lets you tweak resolution, aspect ratio, fps, and audio channels. It is simple, fast, and also gives basic editing options if you want your video polished before saving.

Step 1Search for VEED.IO - MP4 to MKV in your browser and open it.

Step 2Click Choose MP4 File > Upload a file to upload your MP4 video.

Step 3Convert to option is MKV already, so you are settled.

Step 4Hit Convert to initiate the MP4 to MKV conversion process.

Other options VEED.IO offers: Edit videos, add filters, adjust colors, change speed, add effects, fix sound, and use fade-in or fade-out transitions.

Part 3: How to Convert MP4 to MKV on iPhone

1. The Video Converter

If you use an iPhone and want to change MP4 into MKV, The Video Converter app helps. The conversion happens on a secure cloud server, which makes it fast and light on your phone. Most files finish in under 15 seconds. Once done, you can AirDrop your MKV to your Mac or share it in apps.

Here is how to change MP4 to MKV using it:

Step 1Install The Video Converter by Float Tech, LLC on your device.

Step 2What you need to do now is go to Photos, select your MP4 video, click Share, select The Video Converter, and your video will be moved to the converter.

Step 3On the drop-down, select .MKV format. Now, click the Convert File button to start the conversion.

Other options The Video Converter offers: Supports many video and audio formats, includes an in-app file browser, and lets you save, share, or view converted videos instantly.

2. Video Converter and Compressor

For iPhone users who want more control, this app is one of the fastest and supports almost all video formats. It can convert MP4 to MKV and also compress videos to save space. You can change resolution, frame rate, bitrate, audio formats, and even subtitle tracks.

Step 1Get Video Converter and Compressor by Inverse.AI on your device.

Step 2Open the converter, click the Convert or Compress button, and import your MP4 video.

Step 3Head to the Format drop-down and select MKV.

Step 4Lastly, click the CONVERT button, and your MKV file will be saved on your device.

Other options Video Converter and Compressor offer: Video and audio compression, video merging, audio converting, audio merging, and support for high resolutions, like 1080p and 720p.

Part 4: Can FFmpeg Convert MP4 to MKV

FFmpeg is a command-line tool that works with almost every video format. Yes, it can convert MP4 to MKV without losing quality. You can choose to re-encode the video or just change the container. If you only change the container, the conversion is fast and lossless, meaning the quality stays the same. It is trusted by many users who work with media files.

Command for lossless conversion:

ffmpeg -i input.mp4 -c copy output.mkv

It keeps the same quality and only changes the container format.

By Bryan Simmonds on Sep 05, 2025