How to Convert MP4 to MKV Online
Convert MP4 to MKV container. Free, fast, and no account required.
Drop your MP4 file here
or click to browse from your device
Supports MP4 · Max 250 MB
🔒 Converted entirely in your browser — your file never leaves your device.
Converting MP4 to MKV changes your file from MP4 (MPEG-4 Part 14) to MKV (Matroska Video). MP4 files are commonly used for Video sharing and streaming and Social media uploads, while MKV is a better fit when you need Supports unlimited tracks and Open-source format. Convert to MKV when an application or platform requires it, or when its strengths suit your project better than MP4. Upload your MP4 file above to convert it in seconds — no software to install and no account required.
What Is MP4?
MP4 is the most widely used video container format. It supports video, audio, subtitles, and still images within a single file. MP4 typically uses H.264 or H.265 video codecs and AAC audio, providing a good balance between quality and file size.
- Video sharing and streaming
- Social media uploads
- Video storage and archival
- Web video embedding
MP4 is a container format that can use different codecs. Compatibility depends on the specific codecs used within the file. H.264 with AAC audio offers the broadest device support.
What Is MKV?
MKV is an open-source multimedia container format that can hold an unlimited number of video, audio, subtitle, and metadata tracks. It is popular for storing movies and TV shows because of its flexibility and support for high-quality codecs.
- Movie and TV show storage
- Archival of video content
- Subtitle embedding
- High-quality video distribution
MKV may not play natively on all devices, particularly mobile phones and some smart TVs. Converting MKV to MP4 improves compatibility for playback.
Why Convert MP4 to MKV?
- 1Convert your MP4 file to MKV format for use in applications that require it
- 2Put MKV (Matroska Video) to work for Movie and TV show storage and Archival of video content
- 3Convert MP4 to MKV right in your browser — nothing to install and no account to create
How to Convert MP4 to MKV
- 1
Upload your MP4 file
Drag and drop your MP4 file into the upload area above, or click to open your file browser.
- 2
Start the conversion
Click the "Convert to MKV" button. The conversion begins immediately and you can track progress.
- 3
Download the result
Once complete, click the download button to save your MKV file to your device.
Privacy & Security
This conversion is processed entirely in your browser using WebAssembly. Your file is never uploaded to our servers — full privacy guaranteed.
Frequently Asked Questions
To convert a MP4 file to MKV, use the upload area on this page. Drag and drop your MP4 file or click to browse your files. Once uploaded, click the "Convert to MKV" button. The conversion will be processed and the resulting MKV file will be available for download.
Yes. This conversion tool is completely free to use. There are no premium tiers, no watermarks applied to your output, and no limit on the number of conversions you can perform. The service is supported by advertising.
MP4 (MPEG-4 Part 14) MP4 is the most widely used video container format. MKV (Matroska Video) MKV is an open-source multimedia container format that can hold an unlimited number of video, audio, subtitle, and metadata tracks. Converting between these formats allows you to take advantage of the strengths of each format depending on your specific needs.
Converting MP4 to MKV makes sense when you need what MKV (Matroska Video) is good at: Supports unlimited tracks, Open-source format, Handles most modern codecs. It is commonly used for Movie and TV show storage, Archival of video content, Subtitle embedding. MKV may not play natively on all devices, particularly mobile phones and some smart TVs. Converting MKV to MP4 improves compatibility for playback.
The output quality depends on the codecs and settings involved. When converting between lossy formats, some quality adjustment is expected. Video and audio conversions in FlipMyFiles are processed in your browser using standard encoding settings designed to maintain good quality.
Yes. Video and audio conversions are processed entirely in your browser using WebAssembly technology. Your file is never uploaded to our servers. The conversion happens locally on your device, providing full privacy.
The maximum file size is 250 MB per file. This limit applies to all format types. For video and audio files, conversion speed depends on your device's processing power since the conversion runs in your browser.