Does all the technical jargon about digital video file formats drive you bonkers? Join the club! Confusion over video file formats is probably the single biggest hang-up for people wanting to upload video to the web. The good news is that with just a little bit of basic knowledge, you shouldn't have any trouble.

First, keep in mind there are 2 broad categories of video formats. Some formats are meant for your finalized video and are called sharing formats. Other formats are used more in the beginning stages of a video project. They are good as raw video master clips. These formats will have higher resolution and larger file sizes than the sharing formats.

Considerations for Internet Video File Formats

If you are making and uploading video to the web, you need to be aware of video formats in any one of these three stages of the process:

  1. What kind of video comes out of your camera? This is often referred to as the source video or raw video format.
  2. What kind of video does your video editing program accept? You want to make sure that whatever comes out of your camera is supported by the video editing program you want to use.
  3. What kind of sharing format is best for the online video platform you've selected ?

When you are evaluating whether a format is the "right" one or not, the three main evaluating criteria are:

  • Size of the file
  • Resolution and overall appearance of the file
  • Compatibility of the file

Depending on how the video clip will function, any one of a dozen or so popular formats will be among the "best" one to choose.

For the Internet, you want smaller file sizes. Even though the web's capacity for video delivery keeps growing, and most people have broadband, it is still best to keep file sizes as small as possible. A large video file is more likely to encounter buffering issues and drive the viewer crazy. The smaller the file size while still maintaining high quality, the easier it will stream, which may very well make the difference between whether someone bothers to watch or not.

There can be huge differences in size from format to format depending on the compression used. I've experimented around with this and I can take the same video, convert it to QuickTime and get an 80 megabyte file or convert it to an mpeg 4 with h.264 compression and get a 10 megabyte file (you can also compress QuickTime using .h264 video codec but...that is another topic)

Rapid Movement and flashy stuff within the video can add to the file size and are more difficult to compress with resulting high-quality. So, it is important to keep that in mind when creating your video.

Common Video File Formats

Now let's go over the most common video file formats. As you probably know, the last 3 or 4 letters on the end of a video file's name indicates format or file container. Just like .doc indicates a word file, .mov indicates a QuickTime move file; .wmv stands for windows media video and so forth.

Here are the common ones, in alphabetical order.

AVCHD (Advanced Video Codec High Definition):

AVCHD (.mts) is a high end, high-definition (HD) format originally developed by Sony and Panasonic for HD home theater systems. It's not a sharing format for the web because it is so huge, but it has become very common as a lot of newer HD camcorders record in this format. Video in this format would be for the beginning of your video project and serves as a master clip you would use to edit with.

AVCHD is in its infancy as a format and since it's still fairly new and compatibility with certain video editing programs may be an issue. Some video editing software applications have begun to support this format but many of can not handle it well yet. Additionally, playback of AVCHD files requires speedy CPUs and a sufficient amount of RAM. That makes this format a little difficult to work with but it maintains high quality. As time goes by, it will no doubt become easier to use.

.AVI (Audio Video Interlaced):

This is a long-time standard developed by Microsoft and has been around as long as digital video has. .AVI files (particularly when uncompressed) tend to be HUGE, way too big for the internet. AVI is more for the beginning of a video project, not the end. In that sense, it is not really a sharing format. They'll slide into just about any video editing program and the quality is still high enough to be a master clip.

AVI is windows-based and is virtually universal. Problem is, not all AVIs are created equally and you can still run into compatibility issues. AVI is what's known as a container format, which means it contains multiple streams of different type data, including a control track and separate video and audio streams. Now, what streams inside the container is not necessarily the same from one avi video to the next as the codecs used for compression can vary.

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.FLV (Flash Video Format):

Next, we'll talk about the .flv format. Flash video is the single most common sharing format on the web today. You'll see the .FLV file extension on videos encoded by Adobe Flash software to play within the Adobe Flash Player. Virtually everyone (99%) has the adobe player installed in their browser and so this has fast become the most common online video viewing platform.

Almost all the video sharing sites stream video in flash. You can upload formats other than flash, and those sites will convert it into flash for streaming to the end user. Notable users of the Flash Video format include YouTube, Yahoo! Video, MySpace, and many others. Many television news operations are also using Flash Video on their websites. Most of those sites accept uploads in a handful of formats like QuickTime, mpeg4, or wmv, and then they convert it to flash or MP4 before actually putting it out on the net.

In addition to the nearly universal flash video player, FLV is popular because it gives one of the smallest file sizes after compression yet it retains fairly good quality.

If you self-host your own videos, you should convert them to flash for greatest compatibility with the highest number of Internet viewers.

Although FLV's are the most common format found on the web today, the standard is moving towards the use of using MP4 H.264 files within flash players as it is compatible with both online and mobile, not to mention some HTML5 browser support (Safari, Chrome).

.MPEG (Motion Picture Experts Group):

MPEG was developed by the Motion Picture Experts Group. This international group was established in 1988 to develop standards for digital audio and video formats but they're not the only group doing so as anyone who studies digital video files formats knows.

MPEG-4 Part 14 (.MP4):

MPEG-4 Part 14 is a great sharing format for the internet. It's small but looks fairly clean. It's the video format employed by a growing number of camcorders and cameras and it is highly recommended.

In fact, YouTube recommends using MP4  format. YouTube accepts multiple formats, and then converts them all to .flv or .mp4 for distribution.

As mentioned earlier, more and more online video publishers are moving to MP4 (with H.264 as the video compression codec) as the standard internet sharing format with use within both Flash players as well as HTML5.    This is the format that we recommend for online delivery.

.WMV (Windows Media Video)

A .WMV file indicates a windows media video file. Windows Media Video is used for both streaming and downloading content via the Internet. Microsoft's Windows Media Player, an application bundled with Windows operating systems, is built for WMV files. WMV files are tiny. WMV will give you one of the smallest final file sizes. As you might expect, this means they are compressed so much they really do not look very good. In fact, I'd say the resolution is pretty crummy. But a tiny file size can be a real advantage for some things. If you get an email with an actual video attached instead of just a link to a video, it is probably a wmv file. They are the only ones small enough to attach to an email.


.MOV is the file extension used to identify an Apple Quick Time Movie. .MOV is an extremely common sharing format. It is considered one of the best looking and it does look great but the files sizes are big. QuickTime hasn't been a Mac-only program for quite some time. QuickTime versions and players exist on almost all PCs. Some people argue that QuickTime is far superior to similar Windows based applications and I personally would fall into that camp. The vast majority of the videos I personally upload to the web are QuickTime format, followed by MPEG4.

If you see a video file on your computer labeled MSWMM, be aware that this is a windows movie maker project file and not a video or movie file designed for sharing. MSWMM will only play within Movie Maker. When you want to save your movie to share it, use Movie Maker to convert it into a sharing format, such as .mpeg4 or .wmv. The difference between sharing formats and project file formats confuses many people. No matter what video editing software you use, a project file is designed for working on within the editing program. You must convert the project file to watch it on any other player.

I hope this information helps you navigate your way through the alphabet soup known as digital video file formats.

About our Guest Author:

The Basics of Web Video File Formats and Video Containers Copy of mamma g 4 e1266269722813 200x200 Lorraine Grula is a longtime video photographer and producer who now shares her expertise online. Lorraine is available for personal consultation and offers one-on-one video production services. She also runs a blog about video production -

  • Reid Peterson

    Very helpful. Thank you. I am curious if anyone knows of a "chart" published online that would show a video file size conversion? For example, if I had a 2 GB.mpg file, I am trying to find out what file format I should convert it to to have the smallest size (and still have "decent" video quality).

  • John Crewdson

    Thanks Lorraine

  • Mohamed Razmi

    thank u vry much..

  • Lalittawan Meekaew

    Very good article. Thanks. :)

  • Karl Valgeir Jonsson

    Thank you, very good information. I booked on my popular.

  • Kris Holt

    Thanks Lorraine! Awesome info!

  • Amanda Stockley

    Thanks for that, very helpful.

  • Hal_Desk

    Great Post. I recently found this article which gives some forther insight into video encoding and formats for the web:

  • Hansekarl

    woo, it is cool.

  • ipadvideoconverter

    How about MKV? You can add this one.

    • Mark Robertson

      True true - good container, also basis for webM.

  • Gordenbrown36

    very very great post ,speacially for those who uploads video regularly. as my personal thought, FLVvideo is best for web video , coz it much small than the others .

  • Satyagrahi_2010

    nice one ... thanks for posting...

  • phalanxvideo

    Good comprehensive article. If you are looking for help with online video formats then contact us and we will help you out. Online video formats are becoming more and more important these days. Tampa Video Production is what we do. PhalanxVideo production is our name.

  • Video Production

    H264 is currently open source, but I read that it will be reviewed in 2012/3 - so be aware if you are getting heavily into that format - it may come with a price tag soon..

  • Grant Crowell

    Speaking on the subject of MPEG-4 as the recommended format for online delivery. I would be interested to hear about a recommended (ideal) solution for web display. (Meaning, the ideal quality for display in 1280 x 720 HD format online, without needing to go higher res for offline publishing. This would involve 1) A quality camcorder that can automatically save to MPEG-4 or .MOV files with either a hard drive or removable digital media drive (so it doesn't take forever to transcode), and 2) Any software program(s) that can work directly with these file formats in that resolution, for best-of-quality editing and exporting.

    If iMovie and Final Cut/Express are keen for that job, then that takes care of part number 2. (I presume Adobe Premiere does on the Windows side, too.)

    I know of one camcorder that can save directly in Quicktime .mov files (The JVC GY-HM100U is advertised as such which you can see at But its $3,500 price tag can make it well over the range of all but serious aficionados (who aren't videographers by profession).

    So what's the best solution for working with a camcorder that's an ideal match of speed of encoding to image/audio quality? I don't know if you can just use a regular firewire/USB 2.0 HD camcorder and plus that directly in to your laptop, and use a software/hardware solutions for immediate transfer, too?

  • mindbox

    Great Article! AVCHD is definitely the format of choice moving forward, and if you were to buy a camera today you want to make sure it is using AVCHD as its file format. As stated in the article most video editing application don’t support, as of yet, I know Final Cut doesn’t. If you are using Final Cut you will need to convert it to PRORES. However if you are using Adobe Premier it works natively, but you better have a monster workstation to get real-time playback. Thanks again for the article.

    • Jeet

      Nice, this is a tough and complex subject to summarize, but good job. I would like to mention that MKV is becoming a popular web video solution for HD long form content since it can hold and contain so many features like multiple video & audio tracks (director's commentary), subtitles, etc...

  • preetam

    Pretty darned good summary, Lorraine!

    And Silvia: very good clarifications from you, as well.


  • SilviaPfeiffer

    You forgot to mention Ogg as a container format for video. It is being used by the open codecs Theora and Vorbis, which are being used by several Web browsers for their new HTML5 media elements.

    Also, I would recommend keeping a clear distinction between encapsulation formats (Ogg, WMV, FLV, MOOV, MPEG-TS) and the codecs that are used to compress audio-visual content for transport inside these formats (video codecs: MPEG-1 video, MPEG-2 video, MPEG-4 video, H.264, Theora, VC-1 and the audio codecs: MP3, AAC, Vorbis).

    • Mark Robertson

      You are absolutely right. Thanks for that. I meant to take out MPEG1,2 and

  • lorrainegrula

    Hi all.
    File formats is such a huge subject. Silvia makes good points, I am trying to cover the basics. File formats confuse a lot of people, I hope this article clears up some of the basics for people.

  • # azumaguy

    Thanks, good info, dude, er, Lorraine!

  • Klessblog

    Nice post Lorraine, thanks for sharing the detailed explanation of digital file formats on ReelSEO!

    • registrycleaner

      Great Article! AVCHD is definitely the format of choice moving forward, and if you were to buy a camera today you want to make sure it is using AVCHD as its file format.