What is an MP4 file?

Nataliia Paraskeva Jun 24, 2025

MP4 is a media file format that can contain video, audio, subtitles, and images. It's a popular format, widely used both online and offline. MP4 is often preferred due to its broad compatibility and small file sizes.

MP4 files are efficiently compressed, resulting in a portable file with minimal quality loss. That provides an obvious benefit, both for the Net and for local storage. Small MP4 videos can be embedded, bought, downloaded, and shared. They are great for devices with limited storage capacity, such as mobile phones. This is helped by the fact that the format is widely supported.

Most commonly, .mp4 contains MPEG-standard video and AAC audio. At the time of their appearance, the codecs had very little competition. Because of that, they were coded into hardware and adopted by Apple and Microsoft. Now that you're up to speed, read below for some more info about these codecs. And if you’re looking at how to play MP4 files, we have reviewed the best MP4 player for Mac in our article.

How to open MP4 files on Mac?

While MP4 is a common video format, native macOS player QuickTime doesn't support all the codecs that MP4 files can have, which can cause playback issues. But there are a bunch of media players that can handle MP4 files on Mac without any hassle, for example Elmedia Player. Elmedia is a full-featured player for macOS that easily handles MP4, WMV, MKV, AVI, and many others. It offers advanced playback controls and even allows you to stream content to AirPlay, Chromecast, and DLNA devices.

1. Download Elmedia Player and install the app on your Mac.

2. To play MP4 files, add them to Elmedia’s library. There are several ways to do so:

Drag and drop the MP4 file(s) onto the player window or onto its icon in the Dock.
Right-click on the MP4 file, choose "Open With”, then select Elmedia Player from the list of available option.
From the Main Menu, click on File > Open, then choose the MP4 file that you’d like to open.

3. Sit back and enjoy your MP4 files!

Step 4: Finalize Your Choice

Now that the steps on how to change default video player are complete, you should click "Change All". That will apply your new settings to every file of the appropriate type. One more confirmation, and you’re all set.

Convert MP4 Files into a Format Compatible with QuickTime

To open MP4 files seamlessly in QuickTime Player, you can convert the MP4 file to a format that it supports, usually MOV. You can do this directly in QuickTime or choose a third-party video converter, such as HandBrake or Permute. For quick conversion without installing third-party applications, you can also use online tools that allow you to convert MP4 to MOV directly in your browser.

MP4 to MOV conversion completed on CloudConvert

What is an MP4 File Format Capable Of?

Let's take a look at the key capabilities of MP4 files and their advantages:

High compatibility. MP4 is compatible with almost all devices and media players, including computers, smartphones, and media players.
Versatile use. MP4 is used for various purposes, including online video sharing, streaming, digital downloads, and more.
Support for images and subtitles. MP4 can also contain images and subtitles.
Streaming compatibility. MP4 files are widely compatible with various streaming protocols and are also suitable for online video playback.
Compression. MP4 uses compression methods to reduce file size while maintaining acceptable quality.

MP4 Advantages Over Other Formats

Media formats don't exist in a vacuum, and there's almost always a choice. Given how often MP4 is chosen over other formats (for example, AVI and MKV), or even its direct competitors (such as WebM), it's bound to have some serious pros.

This is a concise list of said pros:

It's multiplatform. This goes beyond mere compatibility: a lot of hardware has MPEG codecs built into the system, so that they decode faster and with less battery drain.
AAC/AVC, while not the best, are reasonably good at preserving quality.
MP4 supports XMP, an advanced form of metadata. That makes it possible to integrate images, text, 3d graphics, menu systems, etc.
Software for MP4 is easy to find, and there is plenty of it. With popular players (MPC, VLC, etc.), you don't even have to consider if they play .mp4. They do.

The Downsides of Keeping Your Movies in MP4

MP4 is not without its downsides. They are mostly connected with the advantages, creating a trade-off situation. You should definitely weigh up MP4 advantages and disadvantages, especially if you want to convert many videos and store them for a long time.

Here are some examples:

Not every codec is supported perfectly. Some may, for example, cause audio drifting.
If there's no native support for the format, decoding may be resource-intensive. That goes double for editing, or any non-AVC situation.
MPEG codecs (and most other compatibles) are lossy, and compression is one-way only. You can't restore the quality, resolution, bitrate, etc. to what it was originally.
Some variations of MP4 - m4v, for example - have DRM. It may be great for Apple's profit margin, but definitely not for the buyer.

The Origin of MPEG Standard

MPEG stands for "Moving Picture Experts Group", an international company. True to its name, the company has worked to improve the process of video and audio compression. MPEG-4 is their magnum opus. Primarily, it includes encoding methods (H.264 and AAC) and a container format (MP4). It also describes many other features for playback, storage, and networking. This makes for a very versatile standard.

These features weren't standardized all at once. MP4's staying power owes itself to the format being constantly updated for over a decade. Quite recently (just in July 2020), the MPEG company has undergone some shrinkage and restructuring. Will MP4 stay relevant in a year, or maybe ten? The format's fate remains to be seen. Right now, though, it’s still at the peak of popularity.

FAQ

Does QuickTime play MP4?

Supposedly, QuickTime can open any MP4. At least that's what the website claims; but it's worth keeping in mind that .mp4s can contain many different codecs, including open codes, or those licensed by Microsoft. Apple's obviously not a fan of those.

So what happens if QuickTime player can't open MP4? One of the better alternatives is Elmedia Player - it doesn’t have any issues supporting that multitude of codecs. It’s simple and functional, and all it takes is a few clicks. This MP4 player for Mac brings all popular codecs to Mac.

Alternatively, you can convert the video. There are a lot of converters out there. If you prefer graphics, you’ll likely find many web apps or downloadable converters. And if you aren’t scared of text interfaces, FFmpeg is a good choice, both on macOS and Linux.

Is MOV better quality than MP4?

Depends on the file. But generally, they are very similar. MPEG-4 was made on the basis of QuickTime File Format (.mov). The two file types support the same codecs. However, .mp4 is more advanced in terms of metadata, and it is overall more accessible.

How does an MP4 file work?

An MP4 file contains metadata and some compressed media streams. When a player opens an .mp4, it reads that data to find out how these streams are encoded, and how to sync them up. Then the streams may be decoded and either played, edited, or converted.

What is the difference between MP3 and MP4?

MP3 isn’t designed to hold video data and subtitles, and it lacks many other features than MP4 has. In regards to audio, an MP3 has higher compression. It also has some metadata fields specific to music, such as album and track names, or an image file for the album cover.

Is MPEG-4 the same as MP4?

Pretty much. Either can refer to the standard, or to the container format. If you aren’t writing a research paper, people will understand, and it won’t make much of a difference. You’ll hear "MP4" more often, though. To learn more about what sets the two terms apart, read our MPEG4 vs MP4 comparison.

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Latest version: v8.22(3448), released 20 Jun, 2025 Release notes