MKV to MP4

If you open the Expert Settings, you will see a few options. Here is how to choose the right one for your needs:

• Auto (Recommended): The safest choice. We analyze your file and automatically select the setting that best balances quality and compatibility.
• H.264: The "Compatibility King." Choose this if you want to be 100% sure the video will play on older TVs, older iPhones, and essentially any device made in the last 15 years.
• H.265 (HEVC): The "Efficiency King." Offers the same visual quality as H.264 but at half the file size. Choose this if you are converting for modern 4K TVs or newer smartphones (iPhone 8+, Android 10+).
• VP9: A high-quality, open-source codec used primarily by YouTube. It offers great quality for web streaming but is less supported on older offline players than H.264.

Choose AAC. It is the universal standard for MP4 video and guarantees the sound will work on virtually every TV, iPhone, Android, and game console.

• Auto: Safe to use if you are unsure; we will select the best match for you.
• MP3: Older technology. Only use this for compatibility with very old hardware (15+ years).
• OPUS: Superior compression, but not supported by most TVs. Avoid unless necessary.

• Auto: Leaves your video size untouched (e.g., if your video is 4K, it stays 4K).
• 1080p / 720p: Choose these if you want to shrink the file size significantly or if your device is older and "stutters" when trying to play high-resolution 4K files.

Usually, no. The tool prioritizes a technique called "Direct Stream Copy."

• Scenario A (Lossless): If your MKV file already contains standard H.264 video, the data is simply moved into an MP4 container without touching the video data. This is mathematically lossless.
• Scenario B (Re-encoding): If re-encoding is required to fix compatibility, high-bitrate settings are used to ensure the result is visually indistinguishable from the source.

MKV files often carry cinema-quality surround sound formats (like DTS, AC3, or TrueHD). Most web browsers and basic media players cannot decode these formats, resulting in silence.

The Fix: In the settings, ensure the Audio Codec is set to AAC. This will automatically downmix the surround sound into a high-quality stereo track that works on every device.

Yes, but it is generally not recommended for conversion. While VLC is excellent for playback, its conversion tools are hidden, technical, and often slow. For the best experience, we recommend using the Converter App. However, if you prefer using offline software, here are the steps for VLC:

1. Open VLC and select Media > Convert / Save.
2. Click Add to select your MKV file, then click the Convert / Save button at the bottom.
3. For the Profile, select "Video - H.264 + MP3 (MP4)".
4. Click Start.

This is a common issue. MKV is technically just a "container" (like a box). While your TV might recognize the "box" (the file extension), it often cannot read the specific video stream inside if it uses modern codecs like VP9 or 10-bit HEVC.

The Solution: The converter repackages your video into the universal MP4 standard using H.264 video and AAC audio. This combination is considered the "Gold Standard" and guarantees playback on 99% of Smart TVs (Samsung, LG, Sony), game consoles, and Apple devices.