SNM File

What are SNM files and how to open them

Are you having problems opening a SNM file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your SNM files.

What is a SNM file?

SNM files have multiple uses, and Netscape Mail Message is one of them. Read more about the other uses further down the page.

Netscape Mail Message

We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

How to open SNM files

Important: Different programs may use files with the SNM file extension for different purposes, so unless you are sure which format your SNM file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested two different SNM openers which you will find listed below.

Last updated: August 13, 2026

All known file formats using extension .SNM

While Netscape Mail Message is a popular type of SNM-file, we know of 3 different uses of the .SNM file extension. Different software may use files with the same extension for different types of data.

Smush Animation Format (new)

The Smush Animation Format is an accelerated, proprietary video file format developed by LucasArts for storage and playback of cut-scenes and in-game cinematics in their adventure games during the Grim Fandango era and similar titles. It is used to deliver sequences combining video frames with audio, packaged into a single "movie" file that the game engine reads during gameplay. These files are typically embedded in larger archives (e.g. LAB files), compressed (e.g. with gzip), and decompressed at runtime before being handled by the engine.

Production of an SNM file involves creating video frames encoded in 16-bit color (565 format) along with audio data using codecs such as VIMA. When the game runs, the Smush engine decodes both the video and audio chunks, applying sub-codecs per frame, reconstructing the display using diff buffers, palette data, and sometimes codebooks for glyph compression. The animation is synchronized, but the frame delay field in the format appears to be ignored in many samples; instead a standardized delay (approximately 66,667 microseconds per frame) is applied.

On a technical level, an SNM file begins with four ASCII bytes "SANM" at offset 0, immediately followed by a standard "SHDR" (video header) chunk at offset 8 that carries essential information such as version, frame count, resolution, color palette (256 colours), image type, maximal frame buffer size, and other metadata.

SNM opener for Windows

We have identified one SNM opener that is compatible with this specific type of SNM file.

SnevenTracker Module

We know that one SNM format is SnevenTracker Module. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of SNM files. Remember, different programs may use SNM files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about SNM file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.