Convert MKV to MP4 Free — Online MKV Converter
Convert MKV to MP4 online for free. Transform MKV videos to universally compatible MP4 format in your browser.
Access and pricing
Supported tools include 5 free on-device uses per day, shared across eligible tools. On compatible devices, guest access needs no sign-in. Signed-in users also get 5 daily eligible on-device uses. AI and cloud processing use credits separately.
New accounts can claim 20 welcome credits once. Eligible offers in MiOffice can earn up to 80 reward credits; offer conditions apply.
Starter costs $6.99/month and includes 250 credits at each paid renewal plus unlimited eligible local processing. Unused credits roll over. The $2.99 Day Pass covers 24 hours of eligible local processing; AI and cloud credits are separate.
Compare tools using a representative file and inspect the export. Check supported formats, device compatibility, processing location and the displayed cost before starting. This article is published by MiOffice; consider its recommendations with that affiliation in mind.
Access and pricing updated October 30, 2026. This editorial update does not indicate a new test run.
MKV (Matroska Video) is a powerful container format that supports multiple audio tracks, subtitles, and chapter markers. But its biggest weakness is compatibility. With 38,000 monthly searches for "mkv to mp4," tens of thousands of people hit this compatibility wall every month.
MiOffice converts MKV to MP4 directly in your browser using FFmpeg WebAssembly. No file upload to any server, no software installation, Guest access on supported tools; AI requires sign-in and credits.
How to Convert MKV to MP4
- 1
Open the MKV to MP4 Converter
Go to the MKV to MP4 converter.
- 2
Select Your MKV Files
Drag and drop your MKV file(s). Choose quality: High, Medium, or Low.
- 3
Download MP4
Click convert. Your MP4 files are ready -- compatible with every device and platform.
MKV vs MP4: Compatibility Comparison
| Platform | MKV Support | MP4 Support |
|---|---|---|
| iPhone / iPad | Not supported | Native |
| Android (stock) | Partial | Native |
| Smart TVs | Varies by brand | Universal |
| Web browsers | Not supported | Native |
| Social media | Not accepted | Required format |
| VLC Player | Supported | Supported |
When to Keep MKV
MKV excels at storing high-quality video with multiple audio tracks and subtitle streams. If you watch videos exclusively on a PC with VLC or a media server like Plex, MKV is fine. Convert to MP4 when you need to play on mobile devices, upload to social media, embed on websites, or share with others.
Need to Save Subtitles First?
MKV files often contain embedded subtitle tracks that are lost during conversion. If your MKV has subtitles you want to keep, use the subtitle extractor first to save them as SRT files, then convert the video to MP4.
Privacy
MiOffice processes your MKV files locally using FFmpeg WebAssembly. No file is uploaded to any server. The conversion runs entirely in your browser tab.
Process Your Video Now
MiOffice AI is an AI-powered digital workspace studio. Create, edit, convert, compress, collaborate, and share — video, audio, images, documents, scanning, notes, screen sharing, and file transfer. the full MiOffice catalog, all in one place.
Frequently Asked Questions
Why can I not play MKV files on my phone?
Does MKV to MP4 lose quality?
What about MKV subtitles?
Can I convert multiple MKV files at once?
Jay Padimala
CEO & Founder
Jay Padimala is CEO and Founder of MiOffice, a product of JSVV SOLS LLC.
View all posts by Jay PadimalaRelated Guides
Convert MOV to MP4 Free — iPhone & Mac Video Converter
5 min readVideoConvert WebM to MP4 Free — Online WebM Converter
5 min readVideoConvert AVI to MP4 Free — Online AVI Converter
5 min readVideoConvert HDR to SDR Video Free — Fix Washed Out Videos
5 min readVideoCompress Video Online Free — No Watermark, No Signup
5 min readVideoBest Free Video Compressors in 2026 Compared — Web Ready
11 min read