Opening UNKNOWN Files

The UNKNOWN file type is primarily associated with an image viewer or document viewer.

UNKNOWN	File extension: UNKNOWN
	File type:	image

What is an UNKNOWN file?

UNKNOWN files mostly belong to an image viewer or document viewer. A file with an unknown extension could be almost anything (a PDF, an audio clip, a voice memo, or a raster image) depending on the program that created it. If you're unsure, let Filext.com identify it for you:

Upload the file
Drag-and-drop your file onto this page or click Choose your unknown file to analyze to select it.
Automatic analysis
Our analyzer reads the file's binary signature (not just the filename) to pinpoint its exact format.
Instant results
We show the detected file type, safely preview the content whenever possible, and list the programs that can open or convert it.

In most cases we can also tell you which application originally created the file, helping you choose the right software to view or edit it - no installs, no sign-ups, just answers.

Ready to find out?
Drag & drop your file anywhere on this page, or click Choose your unknown file to analyze to start the scan.

Before opening any mystery file, assume it could be unsafe. Work through the steps below to identify and open an unknown file safely:

Scan it with your antivirus. If in doubt, upload to a multi-scanner (e.g., VirusTotal) rather than opening it locally.
Identify the file type using a trusted detector (see options below).
Preview it safely in a sandbox or in a browser-based viewer.
Open it with a suitable application, or convert it if needed.

How do you open UNKNOWN files?

You need a suitable software like an image viewer or document viewer to open an UNKNOWN file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your UNKNOWN file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a UNKNOWN file directly in the browser:. Just drag the file onto this browser window and drop it.

Online UNKNOWN Text Viewer

Choose your .unknown file to analyze

or drag and drop it here

Online File Viewer

✈

Read our privacy guarantee in Filext’s terms and privacy policy

Please allow ads on our site

This helps us keep our servers running. Then re-upload your file to view it.

Click here to see how to disable the ad blocker for filext.com

Programs that open and convert UNKNOWN files:

an image viewer or document viewer
See the previous paragraphs to learn more about the main application. UNKNOWN files are often referred to as an image viewer or document viewer data files because this type of file is primarily created or used by this software.
7-Zip (compressed data) by Igor Pavlov
7-Zip is a cross-platform program for compressing and encrypting files. It can unpack an UNKNOWN file saved in ZIP archive compression format. This file format is classified as Compressed.
Acrobat (document) by Adobe
Acrobat is a proprietary software for authoring, editing, signing, and reading documents in PDF (Portable Document Format). It can open a PDF file which has UNKNOWN filename extension. This file format is classified as Data.
Sublime (web page) by Sublime
Sublime is a cross-platform code and text editor for desktops. It can edit a HTML web page saved with UNKNOWN filename extension. This file format is classified as Web (source).
VLC (audio clip) by VideoLAN
VLC is a cross-platform is a multimedia streaming and local playback application for desktop and mobile platforms. It can play an UNKNOWN file saved in WAVE audio format. This file format is classified as Audio.
WhatsApp (voice recording) by WhatsApp
WhatsApp is a free instant messaging application compatible with Android, iOS, and Windows. Some OGG audio recordings created with WhatsApp have been found to have UNKNOWN filename extension. This file format is classified as Audio.
XnView (image) by XnSoft
XnView is a cross-platform image editing, organization, and conversion software. It can open and display an UNKNOWN file saved in JPG or PNG format. This file format is classified as Raster Image. Related links: How to Research a File Type FAQ

UNKNOWN file format:

Every file has a defined file format, i.e. how the data is arranged in the file. The file format can be deduced from the file extension and the signature. If the file extension does not match the file format, double-clicking on the file will cause an error upon opening. When there is a problem with a file, the first step to solving it is to determine the file format. Our evaluation of the UNKNOWN files looks like this:

The UNKNOWN extension is quite commonly used. The file itself is used by many programs, each with its own file format. The two most popular formats are as follows:

15% of all UNKNOWN files save the data in JFIF file format. JFIF is short for JPEG File Interchange Format. It is a bitmap graphic that uses JPEG compression. If you open these files in a text editor, you will see only illegible characters. The file size is in the range of 5 KB to 610 KB. The file type was developed only in the last few years. The files contain the following words: JFIF. Unknown. is a typical file name.
15% of all UNKNOWN files are using the well-known PDF file format to store the data. PDF is short for Portable Document Format, is a file format to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. These files contain neither text nor words, but only data. The files are 45 KB to 660 KB in size, with a median of 160 KB. Unknown. is a typical file name. Such files sometimes refer to delivery and proof.

The remaining 70% of all UNKNOWN files are different files with different signatures, the following 8 formats can be found: HTML, PNG, Ogg, ZIP and RIFF. These files sometimes refer to unnamed or node. If you want to find out what your UNKNOWN file contains, drag and drop it onto this page.

Technical Data for UNKNOWN File Extension

File classification:

Data

Related files:

pdf, zip, untitled, pages, check, jpg, noname, docx, rar, file, unknown 3, txt, unknown 2, xlsx, doc, kursbuch mp3, dat, att00001, ss04, mp4, jpf, xpm, xbm

The following listing is compiled from the database produced by the 'Associate This!' program, selected data from the main FILExt database and file extension information submitted by users.

ProgramID: ft000004
EXEFile: %SystemRoot%\NOTEPAD.EXE %1

an unknown image is a special file format and should only be edited and saved with the appropriate software.

How to solve problems with UNKNOWN files

Associate the UNKNOWN file extension with the correct application.
Update your software that should actually open images. Because only the current version supports the latest UNKNOWN file format. Search, therefore, e.g. on the manufacturer website after an available an image viewer or document viewer update.
To make sure that your UNKNOWN file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .UNKNOWN file online - secure, fast, and no downloads needed.