A daily updated filename extension database!

UNK file extension

The table below provides useful information about the .unk file extension. It answers questions such as:

  • What is the .unk file?
  • What program do I need to open a .unk file?
  • How can the .unk file be opened, edited or printed?
  • How can I convert .unk files to another format?

We hope you find this page helpful and a valuable resource!

1 extension(s) and 0 alias(es) found in database

✅ Lotus Notes Unknown Attachment File

UNK file is a Lotus Notes Unknown Attachment File. Lotus Notes is the "classic" client for accessing the Domino/Notes server and processing e-mail, appointments, contacts and much more. The att1.unk file is received by Lotus Notes if the original message was transmitted with MIME encoding.
UNK format description not yet available
Category: Data files
Application: Lotus Notes
Mime-type: application/octet-stream
Magic number: -
Magic string: -
Sample: -
UNK aliases:
UNK related links:
UNK related extensions:
General Data File

Lotus Notes Data

Lotus Notes Content Source

Lotus Notes Template

Lotus Notes Database

Lotus Notes User ID File

Lotus Notes Design Elements

Lotus Notes Redirect File

Lotus Notes Data Link

Lotus Notes Linked Object

Other types of files may also use the .unk file extension.

🚫 The .unk file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

hnk, ink, jnk, knk, nk, ubk, uk, unl

Is it possible that the filename extension is misspelled?

We found the following similar file extensions in our database:

General Temporary File
Garmin Unlock Key
Tablet PC Digital Ink
Internet Explorer HTML Help Index
Starpoint Gemini 2 Junkyard Data
English Language Info File
KNK Studio Cutting Docment
NUKE Script
Embiid Reader eBook

🔴 Can't open a .unk file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows cannot open this file:


To open this file, Windows needs to know what program you want to use to open it...

If you don't know how to set the .unk file association, check the FAQ.

🔴 Can I change the extension of files?

Changing the filename extension of a file is not a good idea. When you change a file's extension, you change the way programs on your computer read the file. The problem is, changing the file extension does not change the file format.

If you have helpful information about the .unk file extension, write to us!

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