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 SVP and General Manager of Lifewire.
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Updated on August 8, 2024
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 VLC, Movies & TV, Windows Media Player, and other apps.
  • MP4s can be converted to 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 how to convert one to other video formats that might work 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.

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 to open. Since most people already have a compatible player installed, such as Microsoft's Movies & TV or Windows Media Player, the MP4 should open automatically.

If the MP4 doesn't open, then you probably don't have a program installed to view and edit it. We recommend the free VLC player. This fantastic MP4 file player supports this video format and many others, including audio files, on all the major operating systems.

If your favorite video player doesn't open MP4 files, you may need to install an MPEG-4 codec. This 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 free collection of popular codecs that works in most versions of Windows. After installation, you'll be able to play MP4 and 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 iPad, iPod touch, iPhone, and Android devices. You don't need to install an app to play MP4 videos sent to you over text or opened on web pages.

Several programs also allow editing of MP4 files for free, like VSDC Free Video Editor and Lightworks.

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 these files, change which program opens MP4 files by default 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, and AVI. Another option is to use Zamzar to convert MP4 to WEBM, MPG, AC3, OGG, FLAC, MOV, and other formats.

Zamzar also supports MP4 to GIF conversions to convert a video file to an animated image. TinyWow is another method. A different converter like Ezgif is a better option if the video exists online.

These converters work online in your browser, so it might take a while for the video to upload since most videos are pretty large. Also, after the video is converted, you must download it again to get it back on your computer, which might not be a quick process.

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

If you just want to mute the video, TinyWow works great for that.

Still Can't Open It?

Double-check the file extension if none of the programs mentioned above will open your file. What's probably happening is that you're misreading the file extension, confusing a similar one with MP4. M4P is a prime example.

Lifewire / Tim Liedtke 
FAQ
  • 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 multimedia containers that can store audio in addition to video, images, and text.

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