What is an MP4 File? (and How to Open or Convert One)

This compressed file format can store video, audio, still images, and subtitle information

By
Tim Fisher
Photo of Tim Fisher, Lifewire GM and Writer
Tim Fisher
Senior Vice President & Group General Manager, Tech & Sustainability
  • Emporia State University
Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the VP and General Manager of Lifewire.
lifewire's editorial guidelines
Updated on November 1, 2022
Reviewed by
Ryan Perian
Ryan Perian headshot
Reviewed by Ryan Perian
  • Western Governors University
Ryan Perian is a certified IT specialist who holds numerous IT certifications and has 12+ years' experience working in the IT industry support and management positions.
lifewire's editorial guidelines

What to Know

  • An MP4 file is also known as an MPEG-4 Video file.
  • You can play one with your favorite media player, or try the free VLC.
  • MP4s can also be converted to other video types like MOV or AVI with Any Video Converter.

This article explains what an MP4 video file is, how to play and edit one, and convert one to other video formats that might work a little better on your device.

What is an MP4 File?

A file with the MP4 file extension is an abbreviation for an MPEG-4 Video file, which is a compressed file format that can contain not only video and still images but also audio and subtitles.

MP4 files are usually seen when you download a video from the internet or use a DVD ripping program to save a DVD to your computer.

Files like this that only have audio are sometimes saved with the .M4A extension.

Lifewire / Tim Liedtke 

How to Open an MP4 File

The easiest way to play MP4 files is to double-click the MP4 and let your computer decide which default application should open it. Since most people already have Windows Media Player or QuickTime installed, the MP4 should open automatically.

However, if no program opens the MP4 file then you probably don't have a program installed that can view and/or edit MP4 files. We recommend installing one of the programs mentioned above, or the free VLC player, which is a fantastic MP4 file player that supports not only this video format but many others, including audio files. MPlayer is another free MP4 player.

If you find that your favorite video player doesn't open MP4 files, you may need to install a MPEG-4 codec. A MPEG-4 codec is a small piece of software that allows your computer to recognize MP4 files and have them play properly in whatever player you use.

X Codec Pack is a completely free collection of popular codecs that works in Windows 10, Windows 8, and Windows 7. After installation, you'll be able to play MP4, as well as almost all other popular video formats, in your favorite player. Just watch out for the ads on that X Codec Pack site—they can look deceivingly like download links!

MP4 files are supported by default on many mobile devices, like Apple's iPad, iPod touch, and iPhone, as well as Android devices. This means you don't need to install an app just to play MP4 videos you receive over text or email or open in web pages.

A number of programs also allow editing of MP4 files for free, like VSDC Free Video Editor and Lightworks. More examples of MP4 editors include MAGIX Movie Edit Pro, Adobe Premiere Pro, and Pinnacle Studio.

If you find that an application on your PC does try to open the MP4 file but it's the wrong application, or if you'd rather have another installed program open MP4 files, you can change the default program for a specific file extension in Windows.

How to Convert an MP4 File

One of the easier to use programs for MP4 conversions is Any Video Converter. It supports saving MP4s to formats like MKV, FLV, AVI, and others.

Another option is to use Zamzar to convert MP4 to WEBM, MPG, AC3, OGG, FLAC, MOV, and other formats. Unlike an MP4 file converting program, these are websites, which means even though you don't have to install any sort of program to use them, you do have to upload the MP4 to the site and then download the converted file before you can use it.

Zamzar also supports MP4 to GIF conversions to convert a video file to an animated image. If the video exists online, a different converter like Imgur's Video to GIF or the ezgif.com website might be a better option.

Remember that because these converters work online, in your browser, it might take a while for the video to upload since most videos are fairly large in size. Also, after the video is converted, you have to download it again to get it back on your computer, which in itself might not be a quick process either.

If none of these options seem to be working for you, there are other free video converter programs and online services that may work out better, some of which also support free MP4 editing, like clipping and cropping.

Frequently Asked Questions

  • What's the difference between M4V and MP4 files? An M4V file is an Apple-developed MPEG-4 video file format that's very similar to an MP4. One significant difference is that M4V files, also known as iTunes Video files, often come with DRM copyright protection, which means your computer must be authorized to play them. 
  • What's the difference between MOV and MP4? MOV files are Apple QuickTime files that store video, audio, and text. Because MOV files are in the QuickTime File Format (QTFF), they work best with Apple devices and QuickTime media players, and they aren't as widely compatible with different devices and software as MP4 files are.
  • What's the difference between MP3 and MP4? MP3 files are an audio-only file format used primarily for music or audiobooks. In contrast, MP4s act as a multimedia container that can store audio in addition to video, images, and text.
Was this page helpful?