What is an MNG file? An MNG file is an animated image saved in the Multiple-Image Network Graphics (MNG) file format. It contains multiple .PNG images that are shown in sequence to convey motion or animation. MNG files are similar to animated .GIF files, but use higher compression and support full alpha (multi-level transparency).

More Information As the PNG Development Group developed the Portable Network Graphic (PNG) file format, they decided to create a separate file format to store animated PNGs. The group reasoned that creating separate file formats for still and animated PNGs would allow users to differentiate between still and animated images more easily. The animated PNG file format was named Multiple-Image Network Graphics, or MNG. Though the PNG format gained widespread acceptance, the MNG format did not. More commonly, users save and transfer animated images as GIFs. Some image viewing and editing applications still allow users to open, edit, and create MNG files, but some programs that previously supported MNG files, such as Mozilla Firefox, no longer do so.