.THM File Extension

When you are capturing video with a digital camcorder or camera, the device creates a thumbnail of the video and saves it to its memory card or internal storage. Then, when you import video from a camcorder or camera, the software you are using to transfer the video also transfers the associated THM files.

Each THM file transferred from a device to a computer shares the same filename as its associated video clip. For example, a THM file for clip001.avi is created as clip001.thm.

You will likely never need to open a THM file since the software program you use to browse video clips displays the thumbnail image next to the video clip.

However, if you encounter a THM file and need to open it individually, you can attempt to open it directly with an image viewer, such as Microsoft Photos, Microsoft Paint, or Apple Preview. If that does not work, you can change the .thm file extension to .jpg and attempt again to open it with an image viewer.

NOTE: If the THM file is not saved in JPEG format, you will likely be unable to open it with an image editor.

If the THM file is saved in JPEG format, you can convert it to other formats with many image editors, including Microsoft Paint, Adobe Photoshop, and Apple Preview.

For example, Paint can convert THM files saved in JPEG format to the following formats:

• .JPG - JPEG Image
• .JFIF - JPEG File Interchange Format
• .PNG - Portable Network Graphic
• .GIF - Graphical Interchange Format
• .TIF - Tagged Image File Format
• .BMP - Bitmap Image
• .HEIC - High Efficiency Image Format
• .DIB - Device Independent Bitmap

You can open THM files with various image viewers and editors, such as Microsoft Photos (Windows) and Apple Preview (Mac). For example, to open a THM file with Preview, select File → Open.

Apple Preview and Microsoft Photos can convert THM files to other formats.

For example, Preview can convert THM files to the following formats:

• .JPG - JPEG Image
• .PNG - Portable Network Graphic
• .TIF - Tagged Image File Format
• .EXR - OpenEXR Image
• .HEIC - High Efficiency Image Format
• .PDF - Portable Document Format

Select GoPro cameras create THM and .LRV files to accompany captured footage to aid you as you browse through your footage on the camera screen or your mobile phone (using the Quik app). For example, a GoPro HERO2 user will find a THM and LRV file next to their .MP4 video.

The THM file is a small preview (typically 160x120) created from a single frame in your footage that is also small in size to allow for quicker loading times as you scroll. Additionally, the LRV file is a low-resolution video utilized during the editing process to reduce the amount of computing power required to edit a video.

Deleting GoPro THM files

You can delete THM files to remove clutter, but it may affect the speed at which you can preview footage on the camera or in the Quik app. However, the actual footage will not be affected.

THM files are not meant to be manually opened. Instead, GoPro cameras and the Quik app (iOS and Android) reference them for quicker loading times as you browse through footage.

However, since the files are saved in a JPEG format, you may be able to view them with an app that supports JPEG images.