BLT File

What are BLT files and how to open them

Are you having problems opening a BLT 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 BLT files.

What is a BLT file?

A .BLT file is a Saved AIM Buddy List file.

Saved AIM Buddy List files store a list of contacts (screen names) for use with the AIM instant messaging program. These files are created when AIM users choose to export or save their Buddy List, including any contact groups, nicknames (friendly names), display settings, and other preferences.

These files are text-based configuration files rather than proprietary binary data. AIM writes them as a structured export of user settings and contact information, so they can later be read back by AIM or examined with text editors or forensic tools. They typically list default and custom contact groups (such as Buddies, Family, Recent Buddies), and for each contact, include properties like nickname, display preferences, and group membership.

The format begins with the ASCII signature "Config{" at the very start, followed by sections identified by keywords such as CONFIG, VERSION, USER (including a screenName field), LOGIN settings (including proxy-related fields, autoLogin, reconnect flags), and BUDDY sections with LIST and subgroup definitions.

How to open BLT files

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

While we have not verified the app ourselves yet, our users have suggested a single BLT opener which you will find listed below.

Last updated: August 24, 2026

Various apps that use files with this extension

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