| 3gp |
Media |
Text, compressed audio, and/or compressed video, specially designed for use with mobile phones. Explained a bit by RFC 3839. |
| amr |
Audio |
Compressed mono audio for GSM networks. |
| gif |
Image |
Typically cartoonish or images with a limited number of colors. It used to be a much more popular format, but it is being phased out slowly. |
| jad |
App Desc |
Java midlet descriptor. This gives information about the Java program, such as which category the program should go into, the midlet's name, and who made it. |
| jar |
Application |
Java midlet program. This is the compiled Java program. Many fun games and other applications are made into Java midlets. |
| jpg, jpeg |
Image |
Compressed images that are usually photographs. Great format. Life is good. |
| m4a |
Audio |
The compressed audio layer from an mp4 file. |
| mid, midi |
Music |
These are tiny sound files. It is essentially "sheet music" that your phone translates into a song. Great for the small size. Most often, they are used as polyphonic ring tones. AnvilStudio is free and will let you edit midi files. |
| mmf |
Audio |
Another version of compressed music. Same suggestions go for this one as for the mp3 format. |
| mp3 |
Audio |
Compressed music, and a very common format for music that you will find online. If you are sending this to your phone, most likely you will want to make it mono and some low bitrate to keep the size down. Lots of phones don't support mp3 files. I might suggest only 30 second clips, and downgrade them to mono, 96k/s or similar. |
| mp4 |
Media |
Compressed video that some of the newer phones support. |
| png |
Image |
Designed to replace gif because Unisys irritated programmers about a software patent. A good format to pick for your phone or web site. Better compression for cartoons and animations. |
| wav |
Audio |
Uncompressed audio. This is the "standard" for ripping music (before it is compressed to mp3), and it is a common Windows file format. If you want to play this on your phone, make the sound samples short, mono, and probably 8khz. |
| wbmp |
Image |
Wireless BMP files -- not the same as a Windows BMP file. A Windows BMP file can be converted into a wbmp file with WapTiger's bmp2wbmp utility, or you can use their online form. This is a black and white format only. |
| wma |
Audio |
An audio file that has been compressed into a Windows Media Player type of format. Much smaller than wav files. |
| cab |
Data |
Some phones let you send cab files as a way to transfer data. |
