Owners of smartphones based on Android often encounter mysterious files when viewing the contents of the internal memory through the file manager. One of the most common and most problematic objects are objects with names like thumbdata3-1967290299. These files often take up hundreds of megabytes or even several gigabytes of free space, forcing users to question their nature and the possibility of deletion.
At their core, these are system databases of thumbnails that the operating system creates to speed up the gallery. When you open a folder with photos, the system does not generate a preview of each photo anew, but takes ready-made small copies from this file. This is why the gallery opens quickly, even if there are thousands of images. However, over time, the size of this storage can grow to indecent values.
In this article, we will analyze in detail the mechanism of how the thumbnail cache works, find out why files thumbdata accumulate, and consider safe methods for clearing them. You'll learn whether deleting this data will cause you to lose your personal photos and how to prevent your system cache from bloating again in the future.
Technical nature of thumbdata files
Prefix files thumbdata are specialized databases used by the media scanner Android. Their main task is to store small copies (thumbnails) of all images and video files found on the device. Without the existence of these files, the operating system would have to read the full size of each image every time the gallery was opened, decode it and scale it on the fly.
Such a process would require enormous processing power of the processor and would significantly increase the response time of the interface. The numbers in the file name following the hyphen (for example, 1967290299) are a unique hash amount or identifier that the system assigns automatically. The user does not need to remember these numbers, since the logic of the file does not depend on them.
It is important to understand that the file itself thumbdata does not contain the originals of your photographs in full resolution. It stores only highly compressed, low-quality thumbnails that are necessary solely for the visual display of the grid in the gallery. If you delete this file, your personal photos will remain completely intact in their original folders.
⚠️ Attention: Thumbdata files are hidden system objects. To detect them in most file managers, you need to activate the “Show hidden files” option in the viewing settings.
Why do the numbers in the name change?
The digital part of the file name (hash) is generated based on the path to the DCIM folder and other file system parameters. If you move a folder with photos or change the directory structure, the system may create a new thumbdata file with a different set of numbers, considering the old one irrelevant.
Why is the file size constantly growing
Many users notice that even after cleaning the file .thumbdata3 it begins to take up space again, sometimes reaching 1-2 GB in a short time term. This happens due to the media scanner's algorithm: it constantly monitors the file system for new images. As soon as you take a new photo, download a picture from a messenger, or save a meme from the browser, the system immediately creates its thumbnail and adds it to the database.
In addition, the problem is aggravated by the fact that old thumbnails of deleted photos are not always cleared from the database in a timely manner. If you delete a thousand pictures, their “ghosts” may remain in the file thumbdata, continuing to take up space. The size also depends on the screen resolution of your device: on smartphones with QHD or 4K displays, thumbnails are saved in higher quality than on budget models with HD screens.
There is one more nuance related to the operation of third-party applications. Some photo editing apps or social networks can force rescanning of media files, which leads to duplicate entries in the cache or the creation of temporary files, which are then merged into the main database.
- 📸 Constantly adding new photos and videos to the gallery automatically increases the size of the thumbnail database.
- 🗑️ Incorrect deletion of images by the user often leaves “garbage” in the gallery preview cache.
- 📱 The high resolution of the device screen requires storing more detailed thumbnails.
- 🔄 Third-party applications may initiate rescanning of media files unnecessarily.
Is it safe to delete thumbdata files
The question of the safety of deleting these files is the most popular among users. The short answer: yes, deleting files thumbdata is absolutely safe for the integrity of your system and personal data. It's just a cache, temporary data that can be recreated at any time. Deleting this file will not reset your phone, lose contacts, or delete original photos.
However, you should be prepared for certain consequences immediately after cleaning. The next time you launch the application Gallery you may notice that instead of the usual pictures, gray squares or placeholder icons are displayed. This is normal behavior: the system detected the absence of a sketch database and began the process of rebuilding it from scratch.
At this moment, the device may work a little slower than usual, and the processor may be more heavily loaded, as new thumbnails are being actively created. It is also possible that battery consumption may increase in the first 10-15 minutes of using the gallery after cleaning. Once all the thumbnails have been generated, the smartphone will return to its normal rhythm.
⚠️ Warning: Do not delete thumbdata files just before an important photo presentation or when you need to quickly find a photo. The process of rebuilding the cache may take time depending on the number of photos.
If you deleted the thumbdata file and the gallery is still running slowly, try restarting your device. This will help the media scanner to correctly complete file indexing.
Instructions for deleting through a file manager
The easiest and most affordable way to get rid of an overgrown file is to use a built-in or third-party file manager. You do not need ROOTrights or a connection to a computer. However, it is important to follow the sequence of actions so that the system does not block the deletion of a file that is currently being used by the process.
To begin with, it is recommended to forcefully stop the Gallery application and the Media Storage service. This will release the file from the system lock. After this, you can begin searching and deleting. The algorithm of actions may differ slightly depending on the shell (MIUI, OneUI, Stock Android), but the general logic remains the same.
Please note that in new versions Android (starting from 11 and higher) access to the root folder DCIM and system directories may be limited by policies security. If the standard explorer does not allow you to delete a file, try using specialized utilities like Total Commander or FX File Explorer, which have extended access rights.
☑️ Thumbdata deletion algorithm
After completing the deletion, it is strongly recommended to restart your smartphone. This action is necessary so that the operating system correctly registers changes in the file structure and does not try to access a non-existent address in memory.
Removal through settings and computer
If you do not want to delve into system folders manually, you can use standard means of clearing accumulated information. This method is less drastic, but in some cases it helps reset the cache without directly deleting database files. Go to Settings → Applications → Show system processes Find the application in the list (Media Storage). Go to the "Memory" section and click the "Clear cache" button. In some firmware, the “Clear data” button is also available, which will completely reset the indexing. Be prepared for the fact that after this the gallery will rescan all files on the phone, which can take from 5 to 30 minutes. Settings → Applications → Show system processes.
Find an application in the list Media storage (Media Storage). Go to the "Memory" section and click the "Clear cache" button. In some firmware, the “Clear data” button is also available, which will completely reset the indexing. Be prepared for the gallery to rescan all files on your phone after this, which can take from 5 to 30 minutes.
An alternative option is to connect the smartphone to the computer in file transfer mode (MTP). Through the interface Windows or macOS it is often easier to navigate through hidden folders. Go to directory DCIM/.thumbnails. If the folder .thumbnails is not visible, turn on the display of hidden items in the computer explorer.
| Deletion method | Difficulty | Efficiency | Risks |
|---|---|---|---|
| File Manager | Low | High | Minimum |
| Application settings | Medium | Medium | None |
| Via computer (PC) | Low | High | Absent |
| Third-party cleaners | Low | Variable | Advertising in applications |
The most reliable way is manual deletion through the file manager after stopping the media storage service. This guarantees freeing up space immediately and completely.
How to prevent file re-creation
Unfortunately, it is impossible to completely prevent the system from creating files thumbdata without losing the functionality of the gallery. If you delete the file and disable its creation, viewing photos will become a pain: each image will take several seconds to load. However, you can control the growth of this file and prevent it from occupying a critical amount of memory.
One of the effective methods is regular preventive cleaning. Set a reminder to check the folder size once a month .thumbnails and empty it when the 100-200 MB limit is exceeded. It also helps to delete duplicate photos and low-quality pictures that you won’t view anyway.
There is an advanced method for experienced users: creating an empty stub file with a write ban. Using ADB or a file manager with ROOTrights, you can create a file named thumbdata3-1967290299, make it empty and set the “Read-Only” attribute. The system will try to write data to it, receive an access error and leave the file empty.
adb shelltouch /sdcard/DCIM/.thumbnails/thumbdata3-1967290299
chmod 444 /sdcard/DCIM/.thumbnails/thumbdata3-1967290299
Use this method with caution. On some devices this may lead to cyclic errors in the system logs or unstable operation of the gallery. If after applying the method you notice failures, simply delete the stub file and restore access rights.
⚠️ Attention: Settings interfaces and file paths may differ depending on the version of Android and the smartphone manufacturer. Always check the latest documentation for your device model.
What to do if a file is deleted but space is not freed up?
The file may be damaged or locked by a process. Try rebooting into safe mode and deleting the file from there, or use your computer to delete via MTP.
Frequently asked questions (FAQ)
Can I delete the entire .thumbnails folder?
Yes, the folder .thumbnails can be deleted completely. The system will automatically create it again the next time it scans media files. This is even more effective than deleting individual files internally, since you get rid of all the temporary data at once.
Why does the thumbdata file weigh more than all my photos?
This is an anomalous situation that usually indicates an error in the media scanner or the presence of broken image files that the system cannot process correctly. In this case, it is recommended to clear the cache of the Media Storage application and check the memory card for errors.
Will deleting thumbdata damage my videos?
No, the files thumbdata contain only static preview frames for video files. The video recordings themselves are stored in separate files of the format MP4, MKV or 3GP and are in no way connected with the thumbnail database. Your videos will remain untouched.
How to find this file on Samsung or Xiaomi?
On smartphones Samsung i Xiaomi the path is usually standard: internal memory → folder DCIM → folder .thumbnails. If you don't see the folder .thumbnails, make sure that "Show hidden system files" is turned on in File Explorer settings.
Do you need to clear thumbdata on your memory card?
Yes, if you store photos on an external SD card, there may also be a similar folder with a thumbnail cache. Clearing this cache on the memory card will help speed up the work of the file manager when receiving the contents of the flash drive.