NK2 Converter

Extract text from NK2 files


Drop or upload your .NK2 file
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How to extract text from your NK2 file

  1. Click the "Select File" button above, and choose your NK2 file.
  2. You’ll see a preview, if available.
  3. Click the "Convert file to..." button to extract text information.

Convert NK2 to another file type

To convert your NK2 file to another format, you need Microsoft Outlook or other Data software.

  • NK2 to CSV
  • NK2 to TMP
  • NK2 to TEMP
  • NK2 to CACHE
  • NK2 to LOG
  • NK2 to BAK
  • NK2 to OLD
  • NK2 to NEW
  • NK2 to PART
  • NK2 to DOWNLOAD
  • NK2 to CRDOWNLOAD
  • NK2 to LOCK

Convert a file to NK2

To convert other file formats to the "Email Contact Cache" file type, you need software like Microsoft Outlook or a similar tool.

  • DEVICE to NK2
  • CACHE to NK2
  • SOCK to NK2
  • SYMLINK to NK2
  • PID to NK2
  • MOUNT to NK2
  • FIFO to NK2
  • LOG to NK2
  • PIPE to NK2
  • TMP to NK2
  • JUNCTION to NK2
  • TEMP to NK2

About NK2 files

The .NK2 file is a legacy proprietary binary format used by older versions of Microsoft Outlook (primarily 2003, 2007, and 2010) to store the "AutoComplete" nickname cache. This file contains the list of names and email addresses that automatically populate when you begin typing in the "To" or "Cc" fields.

The primary drawback for users is that .NK2 is a binary file, meaning it cannot be opened or read in text editors like Notepad or spreadsheet software like Microsoft Excel. Furthermore, modern versions of Outlook (2013, 2016, 2019, and 365) have abandoned this format in favor of storing AutoComplete data directly in the mailbox or as Stream_AutoComplete_*.dat files. This leaves many users with orphaned .NK2 files from old backups containing valuable contact information that is otherwise inaccessible.

To retrieve this data, users typically need to convert the .NK2 file into a standardized format. For data recovery and list management, converting to CSV (Comma Separated Values) is the best approach, allowing you to view, sort, and edit the email addresses in spreadsheet software. For migration, the file often needs to be processed by specific import command-line switches to be ingested by modern Outlook versions.

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.



The NK2 Converter Story

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.