Owners of Xiaomi, Redmi and POCO smartphones often face a mysterious memory shortage message when they begin to analyze the contents of internal memory through file managers. When you look at the folders in detail, you get attention from the MIUI/Gallery/cloud/.thumbnails directory or just the thumbnails folder, which can take up gigabytes of precious space. Many users are scared to see the huge amount of memory occupied by these files and wonder if it is safe to delete them and if it will cause malfunction of the device.
These files are miniatures of photos and videos that the system automatically creates for quick preview in the gallery. When you flip through an album, you don't see the high-resolution originals, but these are lightweight copies. If the system loaded a full-size photo every time it scrolled, the gallery would run slowly, and the battery would run out much faster because of the constant load on the processor.
However, over time, the thumbnails cache grows to absurd sizes, especially if you take a lot of pictures or actively correspond in messengers, saving media files. In this article, we will discuss in detail why the thumbnails folder on Xiaomi inflates, how to clean it correctly without losing personal photos and what hidden functions the standard Gallery app hides.
Technical assignment of Thumbnails folder in MIUI and HyperOS
Files with or without the extension inside the thumbnails folder are a database of sketches. Android and MIUI create them to optimize performance. When you open the Gallery app, the system doesn't read every file weighing 5-10 MB, but rather it accesses lightweight copies of a few kilobytes in size, which provides smooth scrolling and instant response to the interface.
The problem arises when the cache cleaner fails or malfunctions. Instead of removing old thumbnails, the system continues to add new ones, creating duplicates or saving sketches of photos that have been deleted long ago, resulting in a Gallery/thumbnails folder that can take 5, 10 or even more gigabytes, which is critical for models with a small amount of internal memory.
⚠️ Note: Deleting the thumbnails folder itself will not result in the loss of your original photos and videos.You only delete temporary sketches that the system will create again the next time you open the gallery, but in a "healthy" amount.
It is important to understand the difference between app cache and system thumbnails. App cache can be cleared through settings, but thumbnails folder often lies deeper in the file structure and requires manual intervention or the use of special cleaning tools. Ignoring the proliferation of this folder leads to the phone starting to run slower, and notifications of space shortage appear more often.
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Regularly cleaning the thumbnails folder can speed up the gallery on older smartphone models where RAM is limited.
Content Analysis: Why the folder takes up so much space
The main reason for the thumbnails directory overblown is because of the Android media scanner. Every time you get a picture on WhatsApp, Telegram, or take a picture with a camera, a new thumbnail is created. If you often delete failed frames or clear chats of messengers, the originals disappear, and their “ghosts” in the form of sketches remain dead weight.
Also, on Xiaomi devices with Xiaomi Cloud or Google Photos enabled sync, the process can be complicated: the system tries to create previews for all cloud albums, even those you rarely open, which leads to a situation where the folder weighs more than all your real photos combined.
There is also a technical bug that is common in some versions of MIUI, where the.thumbnails file is not updated, but grows infinitely in size, writing new data without deleting old ones. Visually, in the conductor, this can appear as one huge file or as many small files whose total weight is not true.
It's worth noting that the format of thumbnail storage can vary. Modern versions of HyperOS use more efficient compression, but the volume of photos is growing, requiring better previews. If you shoot at 200 MP or record video in 8K, the system has to generate heavier sketches to correctly display color and detail.
Instructions for safe cleaning of miniature cache
To free up space, you need to manually clean through a standard conductor, which is the most effective method because it allows you to monitor the process and make sure that temporary files are deleted. It is recommended to back up important data before you start manipulating it, although the risk of losing it is minimal.
Follow a step-by-step algorithm to access hidden system folders:
- 📁 Open the File Manager app and go to the display settings by enabling the option to “Show hidden files».
- 📂 Find the root folder. MIUI, Then go to the Gallery path. → cloud →.thumbnails.
- 🗑️ Select deletion, select all contents of the folder. If the system requests permission confirmation, allow the action.
- 🔄 Restart the device so that the system recreates the required system indexes.
After the reboot, you'll notice that the space has increased significantly, and when you first start the Gallery, the system can run a little slower than usual until it generates a new set of thumbnails for your current photos, which is normal behavior that will soon stabilize.
☑️ Checklist for safe cleaning
If Xiaomi’s standard Explorer doesn’t see the folder or refuses to delete it, you can use a third-party file manager, such as Total Commander or Files by Google. These often have extended permissions to access system directories and can bypass the limitations imposed by the shell.
Automation of cleaning through system settings
You don't have to go manually into the file system every time. The MIUI shell and the new HyperOS have a powerful optimization tool built in that can find junk files. However, standard cleaning is often superficial and doesn't affect the deep cache of the gallery.
Go to the Security → Cleanup app. The system will analyze the device. Often there is a "Clean up garbage" button at the bottom of the screen, but for deep cleaning, click on the "Junk" or "Deep Cleanup" icon. Here you can find the category "Big Files" or "App Cache", where sometimes bloated thumbnail databases are hidden.
It is also worth checking the settings of the Gallery app itself. Some versions of the software have a “Free Space” feature that suggests removing photos already saved in the cloud or clearing the cache of videos viewed. The path to settings is usually at Profile → Settings → Clear the cache.
⚠️ Warning: Don’t use the dubious Play Market client apps that promise to “speed up the phone 2x.” Often they become a source of garbage and intrusive advertising, interfering with Xiaomi’s system processes.
Hidden Cleaning Opportunities Through ADB
Comparison of memory release methods on Xiaomi
There are several approaches to solving the problem of overcrowded memory, and the choice of method depends on your technical background and device model, and below is a comparison table to help you choose the best way.
| Method | Efficiency | Security | Difficulty |
|---|---|---|---|
| Standard cleaning (Settings) | Low. | Tall. | Minimum |
| Delete folder.thumbnails | Tall. | Tall. | Medium |
| Third-party cliners | Medium | Medium | Minimum |
| Reset to factory settings | Maximum | Risk of data loss | Tall. |
As you can see from the table, manually deleting the thumbnails folder is the middle ground, and it gives you the maximum space-free effect without the risk of losing personal data or disrupting the system, as can happen with a full reset or using aggressive optimizers.
If none of the methods helps and the folder continues to grow at an alarming rate immediately after cleaning, this may indicate a software failure in a particular MIUI update. In this case, you should wait for a patch from the developers or consider rolling back on the previous version of the firmware.
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Manually deleting the contents of the folder.thumbnails is the most efficient and safe way to quickly free up several gigabytes of memory without losing photos.
Prevention and optimization of the Gallery
To prevent the problem of blowing up the thumbnails cache from coming back too often, it is worth changing your media usage habits: Try to regularly clean the folders of the WhatsApp Images, Telegram Video downloads, as they generate a huge stream of temporary files.
Use cloud services with smart storage. For example, Google Photos allows you to store originals in the cloud, leaving only compressed copies on the device that require smaller thumbnails. The synchronization setting of Xiaomi Cloud also helps keep the local database in good shape.
Periodically, once in a while 2-3 For a month, check the size of the folder. MIUI/Gallery. If you notice a sharp jump (in place) for no apparent reason (you did not shoot a video in the video). 8K), Clean up immediately without waiting for critical memory filling, which can lead to a cyclical restart of the phone.
Also keep an eye out for Gallery updates through GetApps or Google Play. Developers often release patches that fix memory leaks and thumbnail cache errors. The latest version of the software is the best protection against software bugs.