Extract text from Outlook AutoComplete files (NK2)
To convert NK2 cache files to another format, you need Microsoft Outlook or other Data software.
To convert other file formats to the "Autocomplete Cache File" file type, you need software like Microsoft Outlook or a similar tool.
The .NK2 file format is an AutoComplete nickname cache utilized by older versions of Microsoft Outlook (specifically versions 2002, 2003, and 2007). It locally stores the names and email addresses of contacts that users type into the To, Cc, and Bcc fields. This prevents users from having to manually type out entire email addresses for frequent contacts.
The major disadvantage of the .NK2 format is that it is a closed, proprietary binary format. It is not a standard address book. If you try to open it with a text editor, you will mostly see unreadable characters. Furthermore, Microsoft abandoned this format in modern versions of Outlook (2010 and newer), migrating the cache to a hidden mailbox file or local DAT files. Users often struggle to access their old contacts when upgrading hardware or migrating to a new email client.
Users typically need to convert .NK2 files to CSV (Comma Separated Values) or VCF (vCard) to migrate these hidden contacts into modern address books or other email clients like Gmail. Converting to standard formats ensures you do not lose valuable historical contact data.
This file format is notoriously difficult to open or convert because standard online converters fail to process its proprietary binary structure. Often, only specialized extraction software or the original Outlook application can properly read the data. However, just drag and drop your file to convert.guru to identify the format, inspect the internal content, and view the text. If our analysis detects supported underlying strings, extracting and converting those email addresses to standard text formats may still be possible.
Convert.Guru analyzes your NK2 file, detects the exact format, and lets you read the text inside.
Users also converted DAT, CSV, PST, PRF and OAB files.
If you want to convert NK2 file to CSV, TMP, TEMP, CACHE, LOG, BAK, OLD, NEW, PART, DOWNLOAD, CRDOWNLOAD or LOCK, you can use Microsoft Outlook or similar software from the "AutoComplete Contact Cache" category. In the File menu, look for Save As… or Export….
To convert DEVICE, CACHE, SOCK, SYMLINK, PID, MOUNT, FIFO, LOG, PIPE, TMP, JUNCTION or TEMP files to NK2, try Microsoft Outlook or another comparable tool in the "AutoComplete Contact Cache" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our NK2 converter.