Understanding file formats is an important part of the filmmaking process. You already know the best and popular video formats.

But sometimes, you may come across certain uncommon file formats.

They may appear unexpectedly while transferring or processing multimedia files. One such file format that may baffle you is the THM format.

On importing videos or photos from your digital camcorder’s memory card, you may notice some files have a THM extension along with the original video and photo files.

Suddenly getting a large bunch of THM files may puzzle you. You may want to know what these THM files are.

  • Do you need to keep them or delete them?
  • Are they important for opening videos and photos from your camera?

Here, this article will answer these questions related to THM files from digital cameras, camcorders, or DSLRs.



What Is A THM File?

A THM file is a cache of compressed thumbnail images stored on the hard drive.

The compression allows a computer to store many more thumbnails in memory than it could if they were uncompressed.

One of the most common uses for this file type is storing video files. A THM, or thumbnail, file stores a small image from the video clip’s first frame and is used to easily see the contents of a collection of video clips.

This is a very useful tool for those looking through video clips. It lets you see the first frame of each clip to decide if it’s something you want to watch or not.



THM File – An Introduction

A .THM extension is a thumbnail image file format. Often digital cameras, camcorders, action cameras and smartphones use THM files as a small image representation of a video file they create.

Canon, Sony, Sony Ericsson, GoPro, Olympus, and other brands of cameras use thumbnails of THM format for photo previews of high-quality videos and pictures taken by the camera.

You will find the THM file image is usually from the first frame of the video. Even the name of the THM file is the same as the corresponding video file.

For instance, the video file named Movie00236.MOV will have Movie00236.THM as its thumbnail file.

What Is A THM File

Why Are THM Files Created By Cameras?

The main purpose of creating the THM file is to quickly identify the video file by viewing its thumbnail image.

Also, it’s a small image file that occupies less space and is quick to load on any device, application, or website.

THM files also carry the metadata information and the camera settings of the photo and video recording.

what is thm file

Transferring THM Files

You might be wondering: what happens to THM files when you transfer videos from camera to computer or other storage devices?

THM files are automatically created and saved either on your camera’s internal memory or external SD card.

When you import these videos from the camera to a PC, Mac, or external storage system, the respective thumbnails can get transferred to the computer. You may find metadata information in these THM files.

How To Open THM Files On Mac And Windows?

Almost all image viewer programs can open THM files. But if you are not able to open THM files on your computer, simply convert them to JPEG/JPG format.

Use an image converter program or try renaming the file extension to JPEG.

Windows Photo Viewer, MS Paint, Apple Preview, Adobe Photoshop, and other image viewer programs can open THM extension files.

Should You Delete A THM File?

As mentioned above, THM image files are smaller representations of large-sized or high-quality videos and pictures. You only require the original video or photo for playback, processing, and editing.

Deleting THM files won’t let you see the preview of the video or picture before opening.

So, if the original video or picture is available, there’s no harm in deleting its THM file.

You can save a lot of storage space on your camera memory card and computer.

In order to remove THM files from the camera storage card, just format the SD card in the camera. Make sure your first transfer and backup the SD card files before formatting.

However, practice caution here.

For some digital cameras and apps, deleting the THM files can also remove the video or you may end up facing playback issues. Like in the case of the GoPro camera Quik mobile app.

what is thm file

Retain Your THM Files

If you delete THM files, the app gives a ‘playback not supported’ message and offers to copy the video files to the phone storage to play them.

Hence, for certain applications, it is important to retain the THM files.

So, whichever filmmaking camera you are using, first test by deleting the THM file of any ‘not required’ video.

You can copy a video file from the camera to the computer, if the THM file also gets transferred, delete it.

Now, check whether the original video remains and plays properly.

Also, note that some applications recreate THM files even after deletion. For example, in spite of deletion, an Android phone will again generate THM files whenever you load the Gallery app.

Recover Deleted Thm Files And Videos Using A Professional Recovery Software

You can easily find numerous file recovery tools online. But your videos and photos are precious. So always opt for a secure recovery tool.

A professional video and photo recovery software is safe to download and ensures you get back lost files without hampering the original visual quality.

If you have accidentally deleted a THM extension file from a camera SD card and wish to restore them, use an efficient recovery tool, such as Stellar Photo Recovery.

It can get back all kinds of multimedia file formats, including THM, JPEG, RAW, MOV, MP4, AVI, FLV, etc.

The software is fast to scan and can recover from hard drives, SD cards, and SSDs, etc., of all kinds and capacities.

It works in all cases of formatting, accidental deletion, corrupt SD card, virus infection, and others.

Create Your Own Thumbnails For Videos

You can create thumbnails for your videos and movies.

They not only offer video previews but also help in getting more clicks, in case you want more people to watch your videos on a video content platform.

Filmmakers also use thumbnails for archiving videos. It helps them to manage and organize a huge number of files in their database.

Creating thumbnails is easy. Take a screenshot of the desired visual in your video. Next, use photo editing software to edit it as desired.

You may try online programs like Canva, Creatopy, or photo editing software, such as Adobe Photoshop or Paint Shop Pro.

You can create thumbnails in THM or JPEG/ JPG format.

Here’s how to create video thumbnails using Adobe Photoshop.

THM Files – Wrapping Up

THM files are automatically created along with the videos and uncompressed raw image files in the camera.

The low-resolution THM image file is used by the camera as a preview of the videos and pictures it records.

You can choose to remove THM files to free some space on your drive.

But always ensure that deleting THM files of your camera doesn’t end up removing the original video.

Hope you found this article on THM files helpful.