MP4 to MKV Converter

MP4 to MKV Converter | Online Free Tool | Elysia Tools

Tool usage guide

Learn when to use this tool, what it supports, and how real users apply it.

Key facts

Category: Media
Input types: file, select, number
Output type: file
Sample coverage: 4
API ready: Yes

Overview

The MP4 to MKV Converter allows you to seamlessly convert MP4 video files into the versatile MKV (Matroska) container format. Whether you want to preserve the original streams without re-encoding using the copy option, or transcode to modern codecs like H.265/HEVC or VP9 with custom CRF quality settings, this tool provides a fast and reliable way to repackage your media.

When to use

When you need to wrap an existing MP4 video into an MKV container without re-encoding to preserve original quality.
When preparing video files for media players or home theater systems that require MKV's robust support for multiple audio tracks and subtitles.
When transcoding MP4 videos to highly efficient codecs like H.265/HEVC or VP9 to reduce file size while maintaining visual fidelity.

How it works

1Upload your MP4 or M4V video file up to the 500MB limit.
2Select your preferred video and audio codecs, or choose 'Copy (No Re-encoding)' to instantly change the container format.
3Adjust the CRF quality value if you are re-encoding, then click convert to generate and download your new MKV file.

Use cases

Remuxing MP4 files to MKV containers instantly by copying the video and audio streams without transcoding.
Compressing large MP4 videos into space-saving MKV files using the H.265/HEVC codec and a custom CRF quality level.
Preparing media files for open-source players and home servers by converting legacy MP4 formats to MKV.

Examples

1. Instant Container Remuxing

Home Media Enthusiast

Background

A user has a high-quality MP4 video and wants to change its container to MKV to prepare it for a media server, but wants to avoid any quality loss or long processing times.

Problem

Changing the container format from MP4 to MKV without re-encoding the underlying video and audio streams.

How to use

Upload the MP4 file, set both the Video Codec and Audio Codec options to 'Copy (No Re-encoding)', and run the converter.

Video Codec: copy, Audio Codec: copy

Outcome

An MKV file is generated instantly with the exact same video and audio quality as the original MP4.

2. High-Efficiency Video Transcoding

Video Editor

Background

An editor needs to archive a large MP4 video file but has limited storage space.

Problem

Reducing the file size of an MP4 video while maintaining high visual quality in an MKV container.

How to use

Upload the MP4 file, select 'H.265/HEVC' as the Video Codec, 'AAC' as the Audio Codec, and set the CRF Quality to 22.

FAQ

Can I convert MP4 to MKV without losing quality?

Yes, by selecting 'Copy (No Re-encoding)' for both video and audio codecs, the streams are transferred directly into the MKV container without quality loss.

What is the maximum file size supported?

The converter supports MP4 and M4V video files up to 500 MB in size.

When should I adjust the CRF Quality setting?

Adjust the CRF quality (recommended range 18-28) only when you choose to re-encode the video using codecs like H.264 or H.265.

Does this tool support H.265/HEVC encoding?

Yes, you can select the H.265/HEVC (libx265) video codec option to transcode your video during the conversion.

Can I convert M4V files with this tool?

Yes, the tool accepts both standard MP4 and M4V video formats as inputs.

Video Codec: libx265, Audio Codec: aac, CRF Quality: 22

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Learn when to use this tool, what it supports, and how real users apply it.

Key facts

Overview

When to use

How it works

Use cases

Examples

1. Instant Container Remuxing

2. High-Efficiency Video Transcoding

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