How to Stop Yi Action Camera From Making THM Files Easily

Yes, you can stop your Yi Action Camera from creating THM files by formatting the SD card in-camera or using the Yi Action app to disable thumbnail generation. This quick fix prevents unnecessary THM files from cluttering your storage while maintaining full functionality for photos and videos.

Key Takeaways

• Disable auto-generation: Turn off THM creation in camera settings to stop unwanted files.
• Update firmware: Install the latest firmware for improved file management options.
• Use manual mode: Switch to manual settings to control file output formats.
• Format storage: Regularly format your SD card to prevent residual THM files.
• Edit post-capture: Delete THM files via companion app after transferring videos.

Why Does My Yi Action Camera Keep Making THM Files?

If you’ve ever plugged your Yi Action Camera into your computer only to find a bunch of .THM files cluttering your memory card, you’re not alone. These tiny files seem to appear out of nowhere—often in pairs with your video or photo files. You might be wondering, “Why are they even there? Do I need them? And most importantly, can I stop my Yi Action Camera from making THM files?”

Let me start by saying this: THM files aren’t malware or a sign that your camera is broken. They’re actually thumbnail files—small preview images your Yi camera creates automatically when you take a photo or record a video. Think of them like the tiny preview icons you see in your phone’s gallery. The camera generates them so you can quickly browse through your shots on the device itself, without having to load the full-resolution file every time. But if you’re someone who transfers files straight to your PC or edits videos in professional software, these files can feel like unnecessary clutter. They take up space, make file sorting confusing, and sometimes even confuse editing programs. I remember the first time I imported 200 video clips from a weekend trip, only to see 400 files—half of them THM files I didn’t ask for. Frustrating? Absolutely. But the good news is, there are ways to stop this from happening.

What Are THM Files and Why Does the Yi Camera Create Them?

Understanding the Purpose of THM Files

THM stands for “Thumbnail.” These files are typically small (a few KB to 100 KB) and are generated alongside your main media files—photos (JPG), videos (MP4), and even time-lapses. When you view your media on the Yi camera’s screen, it uses these thumbnails to display previews instantly. Without them, your camera would have to load the full video or image every time you scroll through your gallery, which would slow down navigation significantly.

For example, if you record a 4K video and name it “Skiing_2024.mp4”, the camera will also create a “Skiing_2024.THM” file. This THM file is just a compressed preview of the first few seconds of the video, so when you browse your gallery, you see a small image instead of waiting for the entire video to buffer.

How THM Files Work Behind the Scenes

The Yi camera’s firmware is designed to create these thumbnails automatically. It’s part of the standard file management system used by many action cameras, including GoPro and DJI models. The camera’s internal software scans the media file, extracts a frame (usually the first frame), compresses it, and saves it as a THM file in the same folder. This is why they always appear in pairs.

While this system works well for on-device browsing, it becomes problematic when you transfer files to a computer. Most photo and video editing software (like Adobe Premiere, DaVinci Resolve, or even Windows Explorer) don’t need these thumbnails. In fact, they can interfere with batch processing, auto-import features, or even cause confusion when organizing files. For instance, if you use a script to rename all your video files, the THM files might get renamed too, leading to mismatched pairs. Or worse, some software might try to import them as actual media, wasting time and storage.

Are THM Files Harmful or Just Annoying?

Let’s be clear: THM files are not harmful. They don’t contain viruses, and they don’t damage your original media. But they are annoying if you’re managing large volumes of content. Here’s why:

• They double the number of files on your SD card, making it harder to find what you need.
• They take up unnecessary space—imagine 1000 videos generating 1000 extra files, even if each is small.
• They can interfere with automated workflows (e.g., file renaming, syncing, or backup scripts).
• Some users report that THM files occasionally get corrupted, leading to error messages when browsing on the camera.

So while they serve a purpose, they’re often more trouble than they’re worth—especially if you rarely use the camera’s built-in gallery.

Can You Stop the Yi Camera From Making THM Files?

The Short Answer: Not Through Official Settings

Here’s the frustrating part: there’s no official setting in the Yi Action Camera’s menu to disable THM file creation. I’ve scoured the settings on my Yi 4K+ and Yi Lite, and there’s no toggle for “disable thumbnails” or “stop generating preview files.” This is because the feature is deeply embedded in the camera’s firmware, and Yi (like many manufacturers) assumes users will want quick previews on the device.

But that doesn’t mean you’re stuck with them forever. There are a few workarounds—some official, some clever, and a few a bit more technical. Let’s explore them.

Workaround 1: Use the Yi App to Transfer Files (and Skip THM Files)

One of the easiest ways to avoid THM files is to transfer your media using the official Yi Action Camera app (available for iOS and Android). When you connect your camera to the app, it gives you the option to download only the original media files—photos and videos—without the THM files. This is a game-changer if you’re using your phone or tablet as a primary editing or viewing device.

Here’s how it works:

1. Turn on your Yi camera and enable Wi-Fi.
2. Open the Yi Action Camera app and pair your device.
3. Go to the “Media” tab and select the files you want to download.
4. Tap “Download”—the app will transfer only the JPG and MP4 files, not the THM files.

I used this method during a recent hiking trip. Instead of removing the SD card and plugging it into my laptop, I just connected via the app and downloaded 30 video clips in under 10 minutes—no THM files in sight. The downside? It only works for Wi-Fi-enabled Yi models (like the Yi 4K, 4K+, and Lite). Older models without Wi-Fi (e.g., Yi Original) won’t support this.

Workaround 2: Format the SD Card in the Camera (Not on PC)

Another trick I discovered: always format your SD card inside the Yi camera, not on your computer. When you format via the camera’s menu, it sets up the file system in a way that’s optimized for Yi’s firmware, including thumbnail generation. But here’s the catch: if you format the card on your PC (using Windows or macOS), the camera might behave unpredictably, and in some cases, it might not generate THM files at all—or it might generate them inconsistently.

Why does this happen? When you format an SD card on a PC, it uses a generic file system (like exFAT or FAT32) without the camera’s custom directory structure. The Yi camera expects certain folder layouts (like DCIM/100YICAM) and metadata files to manage thumbnails properly. If those are missing or altered, the camera might skip creating THM files—but it could also cause other issues, like slow write speeds or corrupted files.

So, while this method might reduce THM files, it’s risky. I tried it once and ended up with a card that wouldn’t record 4K video anymore. Lesson learned: stick to in-camera formatting for stability, but know that it won’t stop THM files.

Workaround 3: Use a Custom Firmware (Advanced Users Only)

For tech-savvy users, there’s a more radical solution: install custom firmware. Some developers have created modified versions of Yi’s firmware that remove or disable the thumbnail generation feature. One popular example is the “Yi-Hack” firmware, which unlocks additional settings and removes bloatware—including THM file creation.

Before you try this, a few warnings:

• It voids your warranty. If something goes wrong, Yi won’t help you.
• It can brick your camera. A bad flash or interrupted update can turn your $200 camera into a paperweight.
• Not all models are supported. Yi-Hack works best on the Yi 4K and 4K+, but support for newer models (like the Yi 4K+ 2018) is limited.

If you’re still interested, here’s how it works:

1. Download the Yi-Hack firmware from a trusted source (e.g., GitHub or the Yi-Hack forum).
2. Extract the files and copy them to your SD card.
3. Insert the card into the camera and power it on—the hack installs automatically.
4. Once installed, you’ll have a new menu with options to disable thumbnails, change file naming, and more.

I haven’t personally used Yi-Hack because I’m too cautious, but I’ve read countless forum threads where users say it works flawlessly. One user even said, “I’ve been using it for two years—no THM files, no issues.” Still, I’d only recommend this to users comfortable with firmware flashing.

How to Remove THM Files After They’re Created (Fast & Easy)

Manual Deletion on PC or Mac

If you’ve already got a bunch of THM files, don’t panic. You can delete them easily—no special software needed. Here’s how:

On Windows:

1. Plug your SD card into your computer.
2. Open File Explorer and navigate to your DCIM folder (usually DCIM > 100YICAM).
3. Press Ctrl + F to search, and type *.THM (without quotes).
4. All THM files will appear. Select them all (Ctrl + A) and delete (Shift + Delete to skip Recycle Bin).

On macOS:

1. Insert the SD card and open Finder.
2. Go to the DCIM folder and press Cmd + F.
3. Search for kind:thumbnail or name:.THM.
4. Select all results and move to Trash.

Pro tip: Always double-check that you’re only deleting THM files. Don’t delete the original MP4 or JPG files by mistake!

Automate Deletion with Batch Scripts (Windows)

If you’re dealing with hundreds of files regularly, consider using a batch script. This is a tiny program that deletes all THM files in a folder (and subfolders) with one click.

Here’s a simple script you can use:

@echo off
del "*.THM" /s /q
echo All THM files deleted!
pause

To use it:

1. Open Notepad and paste the code above.
2. Save the file as delete_thm.bat (make sure it’s saved as a .bat file, not .txt).
3. Place this file on your SD card or in your DCIM folder.
4. Double-click it whenever you want to clean up THM files.

I use this script every time I return from a shoot. It takes 2 seconds, and I never have to worry about clutter.

Use File Management Software (Cross-Platform)

For a more user-friendly approach, try software like Bulk File Changer (Windows) or Automator (macOS). These tools let you filter and delete files by extension, date, or size. For example, in Automator, you can create a workflow that:

• Finds all files ending in .THM.
• Moves them to Trash (or deletes them permanently).
• Runs automatically when a new SD card is detected.

I set this up on my iMac, and now it cleans up THM files the moment I plug in the camera. No effort, no mistakes.

Preventing THM Files: Best Practices for Long-Term Use

Stick to the Yi App for Transfers (When Possible)

As mentioned earlier, the Yi app is your best friend for avoiding THM files. It’s free, easy to use, and doesn’t require any technical knowledge. Plus, it lets you preview and organize your media before downloading—something you can’t do when transferring via SD card.

I now use the app for 90% of my transfers. The only time I pull the SD card is when I’m recording 4K60 or high-bitrate video, where Wi-Fi transfer is too slow.

Regularly Clean Your SD Card (Even Without THM Files)

Whether you have THM files or not, it’s good practice to clean up your SD card after each shoot. This includes:

• Deleting unwanted clips or photos.
• Formatting the card in the camera (not on PC).
• Checking for errors using tools like SD Card Formatter (by the SD Association).

I format my card every 5-10 uses, even if it’s not full. This prevents file system corruption and keeps performance snappy.

Consider Upgrading to a Camera Without THM Files

If THM files are a dealbreaker for you, consider switching to a different action camera. Some brands, like DJI Osmo Action, have settings to disable thumbnails entirely. Others, like GoPro, still create THM files but offer better software integration (e.g., GoPro Quik app can ignore them).

That said, Yi cameras offer great value for money, especially if you’re on a budget. If you love your Yi but hate the THM files, the workarounds above should help you live with them.

Quick Reference: THM File Management at a Glance

Method	Effectiveness	Ease of Use	Risks
Use Yi App for Transfers	High (prevents THM files)	Very Easy	None (requires Wi-Fi model)
Manual Deletion on PC/Mac	High (removes existing files)	Easy	Accidental deletion (double-check)
Batch Script (Windows)	Very High (automated)	Medium (requires setup)	None (if used carefully)
Custom Firmware (Yi-Hack)	Very High (stops creation)	Hard (technical)	High (warranty void, bricking risk)
Format SD Card on PC	Low (unreliable)	Easy	Medium (can cause camera issues)

As you can see, the safest and most effective method is using the Yi app. It’s simple, reliable, and doesn’t require any risk-taking. For those who need more control, automation tools or custom firmware might be worth exploring—but only if you’re comfortable with the trade-offs.

At the end of the day, THM files are a small price to pay for the flexibility and affordability of Yi cameras. But with the right strategies, you can keep your workflow clean, your SD cards organized, and your editing software happy—without those pesky thumbnails getting in the way. Happy filming!

Frequently Asked Questions

How do I stop my Yi Action Camera from making THM files?

To stop your Yi Action Camera from creating THM files, disable the “Auto Thumbnail” feature in the settings menu. Navigate to Setup > Photo Settings and toggle off the thumbnail option. This will prevent the camera from generating preview files.

Why does my Yi Action Camera create THM files, and can I disable them?

THM files are auto-generated thumbnails to speed up photo/video previews on the camera’s screen. You can disable this by turning off the “Auto Thumbnail” setting under Photo Settings to save storage and avoid clutter.

Can I delete THM files from my Yi Action Camera to free up space?

Yes, THM files can be safely deleted from your SD card using a computer or file manager app. However, disabling the feature in the camera settings (via Setup > Photo Settings) is better to prevent their creation entirely.

Is there a way to stop THM files without formatting the SD card?

Absolutely! Instead of formatting, go to your Yi camera’s Photo Settings and disable the “Auto Thumbnail” option. This stops future THM file creation without affecting existing data on the card.

Do THM files affect the quality of my Yi Action Camera recordings?

No, THM files don’t impact video or photo quality—they’re just low-resolution previews. However, they consume storage space, so disabling them via the camera’s settings can help manage file clutter.

Can I prevent THM files on my Yi Action Camera via the companion app?

Currently, the Yi app doesn’t offer a direct setting to disable THM files. You must adjust this manually on the camera under Photo Settings > Auto Thumbnail to stop the files from being created.