NV File

What are NV files and how to open them

Are you having problems opening a NV 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 NV files.

What is a NV file?

NV files have multiple uses, and Juno Address Book is one of them. Read more about the other uses further down the page.

Juno Address Book

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 NV files

Important: Different programs may use files with the NV file extension for different purposes, so unless you are sure which format your NV 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 NV openers which you will find listed below.

Last updated: August 10, 2026

All known file formats using extension .NV

While Juno Address Book is a popular type of NV-file, we know of 2 different uses of the .NV file extension. Different software may use files with the same extension for different types of data.

MAME NVRAM File

MAME NVRAM files are created by the MAME emulator to mimic the non-volatile memory (such as EEPROM or battery-backed RAM) found in certain arcade hardware. These files store game-specific data that must persist between sessions - examples include high scores, calibration or cabinet settings, default biases, unlocked features, and other parameters that real arcade machines retained even after being powered off.

MAME writes the .NV file for a given game automatically when that game makes use of non-volatile memory, loading the file when the game starts and saving it again when the emulator exits. These files are stored in a folder called "nvram" by default, though this location can be changed using configuration settings or the command-line option -nvram_directory. Games that do not require persistent non-volatile memory do not use .NV files.

Technical structure details of the .NV file format are not publicly documented in full; they are treated as raw binary blobs mirroring the layout of the arcade hardware's NVRAM/EERPOM device rather than standardized across all games. The file size and internal organization depend on the hardware model being emulated.

NV opener for Windows

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

Various apps that use files with this extension

These apps are known to open certain types of NV files. Remember, different programs may use NV 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 NV file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.