MKV (Matroska Video) is a brilliant container for storing high-quality video — it supports multiple audio tracks, subtitles, and chapters. But try playing an MKV on an iPhone, Apple TV, PS4, Xbox, or most smart TVs and you'll get nothing. MP4 is the format that plays everywhere. Converting MKV to MP4 is the fastest fix.

Why Convert MKV to MP4?

MKV is an open container format popular with Blu-ray rips, anime downloads, and high-quality video archives. It's excellent technically — but poor in device compatibility.

Reasons to convert MKV to MP4:

The good news: since both MKV and MP4 commonly store H.264 video and AAC audio, the conversion is often a remux (just repackaging) — no quality loss, and it takes seconds.

How to Convert MKV to MP4 Free Online

Step 1 — Open the Converter

Go to SolutionGigs MKV to MP4 Converter. No sign-up, no software needed.

Step 2 — Upload Your MKV File

Click Select File or drag your .mkv file into the upload zone. Supports files up to 500 MB.

Step 3 — Choose Quality (Optional)

Open the settings panel to pick a quality preset:

For archiving or uploading to YouTube, use Best Quality or Balanced.

Step 4 — Convert and Download

Click Convert. Most MKV files convert in under a minute. Click Download when done.

MKV vs MP4 — Key Differences

Feature MKV MP4
Device compatibility Limited Universal
Multiple audio tracks Yes Limited
Subtitle support Native (.srt, .ass) Limited
Streaming support No Yes
Social media upload No Yes
File size Similar Similar

Will I Lose Quality Converting MKV to MP4?

Usually no. If the MKV contains H.264 video + AAC audio (very common), the converter can simply re-package the streams into an MP4 container without re-encoding. This is called a remux and produces identical quality.

If the MKV uses a less common codec (like H.265/HEVC, VP9, or DTS audio), re-encoding is needed, which does reduce quality slightly.

Frequently Asked Questions

How long does MKV to MP4 conversion take? For remux (same codec), typically 10–30 seconds for most file sizes. Re-encoding takes longer depending on file size and quality setting.

Can I convert a 4K MKV to MP4? Yes, up to 500 MB. For very large 4K files, consider splitting them first or using a local tool like HandBrake.

Will subtitles be included in the MP4? Embedded subtitles may or may not be preserved depending on the subtitle format. For guaranteed subtitle support, use MKV — or burn them in during conversion.

My MKV has multiple audio tracks — which one gets kept? The first audio track is kept by default. If you need a specific language track, use HandBrake locally.

Is the converter free? 100% free. No account, no limits, no watermarks.