Every owner of a smartphone based on the operating system Android is faced with a situation where, after rebooting or updating the device, the message “Optimizing applications” appears on the screen. This process can take anywhere from a few minutes to half an hour, causing irritation and anxiety for the user. Many people believe that there is something wrong with their phone, although in most cases this is a standard procedure necessary for the software to work correctly.
The essence of the phenomenon lies in the mechanism for compiling application code, which was introduced in version Android 5.0 Lollipop and further developed in subsequent releases. The system prepares executable app files in advance for the specific hardware of your device so that applications launch faster and work more stable in the future. Understanding how Dalvik or ART (Android Runtime) works will help you distinguish normal system behavior from critical failures.
In this article we will look in detail at why the system is forced to perform these actions, how you can reduce the waiting time and whether it is worth interfering with the process forcibly. You'll learn about the technical nuances of the runtime and get practical advice on diagnosing problems if optimizations hang or repeat endlessly.
The technical nature of the process: ART and compilation
To understand what's going on under the hood of your smartphone, you need to look at the runtime architecture. Previously, a virtual machine was used, which compiled application code on the fly (JIT - Just-In-Time) at the time of their launch. This saved memory space, but slowed down apps and increased battery consumption during their use. Android virtual machine was used Dalvik, which compiled application code on the fly (JIT - Just-In-Time) at the time of their launch. This saved memory space, but slowed down apps and increased battery consumption during their use.
With the advent of Wednesday ART (Android Runtime), the approach changed to the opposite - AOT (Ahead-Of-Time). Now the compilation of bytecode into machine code occurs in advance, usually immediately after installing the application or when the system first boots after an update. It is this process that you observe as “Application Optimization”. The system scans installed packages, checks their integrity and creates optimized files .odex (Optimized Dalvik Executable).
If you see this message every time you turn on your phone, it means that the runtime is unable to save compilation results or the cache files are constantly becoming corrupted. In normal mode, this procedure should only be done once after a major firmware update or installation of a large number of new apps.
Technical details of how ART works
The ART environment uses a mechanism in which applications are compiled completely upon installation. This takes more time and disk space during installation, but significantly speeds up the launch of applications and reduces the load on the processor while they are running, which ultimately saves battery power.
Why does optimization run every time you turn on
The situation when a smartphone endlessly optimizes applications every time you reboot is abnormal and indicates problems in the file system or software conflicts. Most often, the reason lies in damage to the data partition or failures in specific applications that cannot correctly complete the initialization process.
One of the common reasons is failure of access rights to system folders. If the runtime ART has no way to write the compiled files to the directory /data/dalvik-cachethe process will start over every time it boots. This often happens after unsuccessful attempts to obtain root access or install custom recovery.
Also, the culprit may be a specific application installed from an unreliable source. Malicious code or an incorrectly built APK file can block the completion of the optimization step, causing the system to retry in a loop. In such cases, logging into Safe Mode to identify problematic software often helps.
⚠️ Attention: If the optimization process lasts more than 30-40 minutes and the phone does not respond to presses, you should not wait forever. A forced reboot may be the only way out, but after it the problem will most likely recur if its root cause is not eliminated.
The impact of system updates and factory resets
The most common and legitimate scenario for the appearance of the optimization screen is updating the operating system to a new version Android or installing a major security patch from the manufacturer. In this case, the version of the runtime environment changes, and all installed applications must be recompiled for new libraries and drivers.
A similar situation is observed after performing a full reset (Factory Reset). When clearing a partition /data all user data and optimization cache are deleted. When you first start a “clean” system, you need to re-analyze the pre-installed applications and prepare them for use. This is normal behavior that does not require user intervention.
However, if you performed a reset and the optimization repeats over and over again even without installing new apps, this is a red flag. It is possible that the firmware file was downloaded with an error, or the phone’s storage device has bad sectors that do not allow data to be saved correctly. In such cases, you may need to flash the device via a computer.
After a major system update, let the phone work for 15-20 minutes in quiet mode without launching heavy games. This will allow background services to complete indexing and optimization without interruption.
Resolving problems through safe mode and deleting the cache
If you suspect that a third-party application is the culprit of the loop optimization, the first step should be diagnostics in Safe Mode. In this mode, only system applications are loaded, which eliminates the influence of the software you installed. If in safe mode the phone boots normally and the inscription disappears, then the problem is in one of the applications.
To enter safe mode, you usually need to hold down the power button on the screen, and then hold down the “Power off” or “Reboot” item for a long time until the corresponding prompt appears. An alternative method depends on the model: often this involves holding down the volume down button while turning on the device.
Another effective method is to clear the cache of the recovery partition (Wipe Cache Partition). This procedure does not delete your personal data (photos, contacts), but it erases temporary system files that may have become corrupted. To do this, you need to boot into mode Recovery (usually a combination of the power and volume buttons) and select the appropriate menu item.
☑️ Diagnostics of cyclic optimization
Remember that clearing cache via Recovery is A safe procedure, but it requires care when navigating the menu, since there are also functions for a complete data reset. Make sure that you select Wipe Cache Partitionand not Wipe Data/Factory Reset.
The role of free space and drive status
For successful compilation of applications, the environment ART requires a sufficient amount of free space on the internal drive. If the phone's memory is full (less than 500 MB - 1 GB remaining), the system may physically not be able to write optimized files, which leads to a crash and repeating the process the next time you boot.
In addition, the physical state of the flash memory plays a critical role. Over time, memory cells wear out and bad sectors may appear on older devices. If the system partition is damaged, writing data becomes impossible, and the phone will endlessly try (complete) an operation that is doomed to failure.
You can check the memory status using special utilities available in Google Play, or through the manufacturer's diagnostic menus (for example, entering a code #0# on devices Samsung). If the tests show read/write errors, software methods for solving the problem will no longer help - you will need to replace the hardware.
| Symptom | Probable cause | Solution method |
|---|---|---|
| Optimization after each startup | Access rights failure or damage to dalvik-cache | Clearing the cache partition via Recovery |
| Stuck on the logo after optimization | System file conflict after update | Reset to factory settings (Hard Reset) |
| Very long optimization (>1 hour) | Slow memory or large number of applications | Waiting or checking the drive for errors |
| Not enough space message | Internal storage is full | Deleting files and applications to free up space |
Myths about overclocking and disabling optimization
On the Internet you can find tips on how to fully disabling application optimization through hidden developer settings or modification of system files. Experts categorically do not recommend ordinary users to do this. Disabling pre-compilation will return the phone to the operation model Dalvik, which will lead to strong heating of the processor, slowdowns when launching apps and rapid battery drain.
Some users try to speed up the process by installing special scripts or modules for Magisk. However, such interventions require deep knowledge of architecture Android. Incorrectly setting compiler parameters can cause applications to crash with errors or stop running altogether.
The only safe way to “speed up” optimization is to let the system shut down quietly, without interrupting the process and without running heavy tasks in parallel. Trying to reboot the phone every 5 minutes only prolongs the problem over time, since the system starts compiling again each time.
⚠️ Attention: Do not try to delete files from the folder
/data/dalvik-cachemanually through a file manager with root access while the system is running. This is guaranteed to lead to a cyclic reboot (bootloop) and the need to flash the device.
Optimizing applications is a necessary process for stable operation of Android. Attempts to disable or bypass it will lead to a decrease in the performance and autonomy of the device.
FAQ: Frequently asked questions
How long should normal optimization take?
Usually the process takes from 2 to 15 minutes depending on the number of installed applications and processor speed. If the procedure lasts more than 30 minutes, this is a sign of a problem.
Can I use the phone while optimization is in progress?
No, at this time the system interface is blocked. Attempting to press buttons or reboot the device can damage system files and make the situation worse.
Why did optimization start after simply turning off the phone?
This is not normal. Most likely, an incorrect shutdown occurred earlier, or one of the system applications was updated in the background, requiring recompilation.
Will resetting the cache partition (Wipe Cache) delete my data?
No, this operation deletes only temporary system files. Your photos, contacts, messages and installed applications will remain safe.
What to do if nothing helps and the phone is stuck?
If clearing the cache and safe mode did not help, the only solution is a full reset to factory settings (Factory Reset) or flashing the device via a computer using official utilities manufacturer.