THM File Extension

THM file icon
Thumbnail Image Format

What is THM file?

THM is a format created for purpose of storing small raster images (thumbnails), which depict equivalent, full-size images/graphics, but in a smaller scale.

Additional information about THM files

THM files are often used in Internet to depict ClipArt images and in Internet galleries, and also in folders on local discs. Thumbnails are very popular, because they enable to browse large images in smaller versions, which substantially quickens browsing and saves space on the screen.

THM files are generated in different graphic and video applications, and by some digital cameras. THM format can be easily converted into the popular JPG or one of other popular graphic formats – it requires only to change the extension within the file name.

Programs which support THM file extension

The following list contains programs grouped by 2 operating systems that support THM files. THM files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Programs that support THM file

Updated: 07/15/2019

How to open file with THM extension?

Being unable to open files with THM extension can be have various origins. On the bright side, the most encountered issues pertaining to Thumbnail Image Format files aren’t complex. In most cases they can be addressed swiftly and effectively without assistance from a specialist. The list below will guide you through the process of addressing the encountered problem.

Step 1. Download and install Microsoft Windows Photos

The most common reason for such problems is the lack of proper applications that supports THM files installed on the system. This one is an easy one. Select Microsoft Windows Photos or one of the recommended programs (for example, ACDSee, Apple Preview, Windows Photo Viewer) and download it from appropriate source and install on your system. On the top of the page a list that contains all programs grouped based on operating systems supported can be found. The safest method of downloading Microsoft Windows Photos installed is by going to developer’s website () and downloading the software using provided links.

Step 2. Update Microsoft Windows Photos to the latest version

You still cannot access THM files although Microsoft Windows Photos is installed on your system? Make sure that the software is up to date. Sometimes software developers introduce new formats in place of that already supports along with newer versions of their applications. If you have an older version of Microsoft Windows Photos installed, it may not support THM format. The latest version of Microsoft Windows Photos should support all file formats that where compatible with older versions of the software.

Step 3. Associate Thumbnail Image Format files with Microsoft Windows Photos

If the issue has not been solved in the previous step, you should associate THM files with latest version of Microsoft Windows Photos you have installed on your device. The method is quite simple and varies little across operating systems.

Change the default application in Windows

  • Choose the Open with entry from the file menu accessed by right-mouse clicking on the THM file
  • Click Choose another app and then select More apps option
  • To finalize the process, select Look for another app on this PC entry and using the file explorer select the Microsoft Windows Photos installation folder. Confirm by checking Always use this app to open THM files box and clicking OK button.

Change the default application in Mac OS

  • Right-click the THM file and select Information
  • Open the Open with section by clicking its name
  • From the list choose the appropriate program and confirm by clicking Change for all....
  • If you followed the previous steps a message should appear: This change will be applied to all files with THM extension. Next, click the Continue button to finalize the process.

Step 4. Check the THM for errors

Should the problem still occur after following steps 1-3, check if the THM file is valid. Problems with opening the file may arise due to various reasons.

1. Verify that the THM in question is not infected with a computer virus

Should it happed that the THM is infected with a virus, this may be that cause that prevents you from accessing it. Immediately scan the file using an antivirus tool or scan the whole system to ensure the whole system is safe. If the scanner detected that the THM file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Verify that the THM file’s structure is intact

Did you receive the THM file in question from a different person? Ask him/her to send it one more time. The file might have been copied erroneously and the data lost integrity, which precludes from accessing the file. When downloading the file with THM extension from the internet an error may occurred resulting in incomplete file. Try downloading the file again.

3. Ensure that you have appropriate access rights

There is a possibility that the file in question can only be accessed by users with sufficient system privileges. Log out of your current account and log in to an account with sufficient access privileges. Then open the Thumbnail Image Format file.

4. Make sure that the system has sufficient resources to run Microsoft Windows Photos

The operating systems may note enough free resources to run the application that support THM files. Close all running programs and try opening the THM file.

5. Ensure that you have the latest drivers and system updates and patches installed

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with Thumbnail Image Format file. It is possible that one of the available system or driver updates may solve the problems with THM files affecting older versions of given software.

Do you want to help?

If you have additional information about the THM file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on THM file.

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