MKV to MP4 converter
Convert MKV to MP4 free online. Remux Matroska to MP4 with no quality loss and keep chapters. No signup, 500 MB limit, files deleted in 1 hour.
Drop a file to convert here
or click to browse
About MPEG-4 Video Format
Common Use Cases
- Converting high-quality video containers for playback
- Ensuring compatibility across all devices
- Streaming video to mobile and web players
MKV (Matroska) is a flexible container format beloved by the torrenting and home-theater crowd because it can hold almost any combination of video, audio, and subtitle tracks in a single file. The problem is that Apple devices, Windows Media Player, and most smart TVs do not natively play MKV, which is where converting to MP4 solves the headache. MP4 is the universal video container, and in most cases the underlying video stream inside your MKV is already compatible with it.
MKV and MP4 are both containers, not codecs, so an MKV-to-MP4 conversion is typically a remux that rewraps the same H.264 or H.265 video into a new container without re-encoding, meaning no quality loss and a much faster process than a true conversion.
Why Convert MKV to MP4?
Play everywhere without codec packs
MP4 plays natively on iPhone, iPad, Mac, Windows, Android, Chromecast, Apple TV, Roku, and basically every smart TV made in the last decade. MKV requires VLC, MPV, or a codec pack on most of these. Converting to MP4 removes the friction so the file just works.
Fast, lossless remuxing in most cases
Because MKV files usually contain H.264 or H.265 video and AAC or AC3 audio, the converter can copy the streams directly into an MP4 container without re-encoding. That means the output is bit-for-bit identical in quality to the source and the job finishes in a fraction of the time a real transcode would take.
Upload to platforms that reject MKV
YouTube, Instagram, Twitter, TikTok, Facebook, and most web uploaders either refuse MKV outright or silently re-encode it on their side. Giving them an MP4 means you control the encode and avoid surprise quality drops during their upload pipeline.
Stream from phones and tablets
AirPlay, Google Cast, and DLNA streamers generally handle MP4 cleanly but stumble on MKV. If you want to fling a movie from your phone to the living room TV, MP4 is the container that actually makes that work.
When to use each
Use MKV when...
- Archiving movies with multiple audio tracks
- Embedding SRT or SSA subtitle files
- Storing high-bitrate HEVC or AV1 rips
- Using open-source tools like Handbrake or mkvtoolnix
- Keeping a lossless master with chapters
Use MP4 when...
- Playing on iPhone, iPad, or Apple TV
- Uploading to YouTube, Instagram, or TikTok
- Sharing via iMessage, email, or cloud storage
- Playing on smart TVs and set-top boxes
- Streaming to Chromecast or AirPlay
Common use cases
- Converting high-quality video containers for playback
- Ensuring compatibility across all devices
- Streaming video to mobile and web players
How to use
- Upload your MKV file. Drag and drop your MKV video onto the upload area above, or click to browse and pick a file from your computer. The maximum file size is 500 MB per upload, which covers most short clips and compressed movies but may be tight for long HD rips.
- Start the conversion. Click Convert File and our servers process the video using FFmpeg, the same engine that powers VLC, Handbrake, and most of the video industry. When the source codec is compatible, FFmpeg remuxes the streams directly into MP4 for a fast and lossless result.
- Download your MP4 file. A download link appears as soon as processing finishes. Save the MP4 to your device and it is ready to play in QuickTime, Apple TV, Windows, or anywhere else. Uploaded and converted files are automatically deleted from our servers within 1 hour.
Frequently asked questions
- Will converting MKV to MP4 reduce video quality?
- Usually not. Most MKV files already contain H.264 or H.265 video, which MP4 supports natively, so the conversion is a remux that copies the video stream bit-for-bit into a new container. The output is identical in quality to the source. Re-encoding only kicks in if the MKV uses a codec MP4 does not support.
- Do subtitles carry over from MKV to MP4?
- It depends on the subtitle format. Text-based subtitles like SRT can often be embedded in the output MP4, but advanced formats like SSA or PGS image subtitles are harder to carry across. If preserving styled or bitmap subtitles matters, extract them separately before converting and keep them as a sidecar .srt file next to the MP4.
- What about multiple audio tracks and language options?
- MP4 technically supports multiple audio tracks, but many players only expose the first one. If your MKV has separate English, Japanese, or commentary tracks, the MP4 may play the default track and hide the others depending on the player. For multi-language archival, MKV is still the better container.
- Is there a file size limit?
- Yes, 500 MB per file. Video is naturally large, so a long HD movie will often exceed that. If your MKV is too big, trim or compress it first using a tool like Handbrake or clip out just the portion you need before uploading.
- Is converting MKV to MP4 free?
- Yes. Anonymous visitors can convert for free with a daily cap, and creating a free FileFactory account raises that cap. Premium and Lifetime members get unlimited conversions with priority processing.
- How long are my videos stored on your servers?
- Uploaded files and the converted MP4 output are automatically deleted within 1 hour. Files are transferred over encrypted connections and never shared with third parties.
- Why not just rename the .mkv to .mp4?
- Renaming the file extension does not change the underlying container structure, so players still see it as MKV and either refuse to play it or play it badly. A proper conversion rewrites the container header and stream indexes so the file is actually a valid MP4.