When deeply configuring or debugging a smartphone based on the operating system Android users often encounter a parameter called “Log Level”. This term may seem complicated to a newbie, but it is actually a fundamental part of diagnosing any system problem. The event log, or Logcat, records everything that happens inside the device: from application launches to server communication errors.
Understanding what the log level is allows you to control the amount of information recorded and filter out unnecessary data. If you choose a threshold that is too low, you will drown in thousands of lines of technical garbage. If it's too high, you'll miss a critical error that causes the app to crash. Let's take a look at how this hierarchy works and where it is used.
In most cases, a standard user never changes these settings, since the system itself optimizes logging for current tasks. However, for developers, testers and advanced enthusiasts, managing log levels is a daily chore. This is the first step to understanding why your phone behaves a certain way.
What is logging and why are levels needed
Logging is the process of automatically recording events into a special text file or memory buffer. In an ecosystem Android the subsystem logdis responsible for this. Imagine that you are keeping a diary of your life. You can record your every movement (“raised your hand,” “blinked”), or you can record only important events (“received a diploma,” “bought an apartment”). The log level precisely defines this line.
Severity level events are assigned by the programmer at the time of writing the code of an application or system service. When an event occurs, the system compares its priority with the currently set filtering threshold. If the event priority is higher than or equal to the threshold, the entry is written to the log. If it is lower, it is ignored and does not take up space in memory.
⚠️ Attention: Constantly recording logs with a low filtering level (for example, VERBOSE) can lead to increased battery consumption and filling up the internal memory of the device, since the processor is forced to process and write a huge stream of data.
Why do you need to change this parameter at all? Most often, this is required when searching for reasons for unstable operation of the firmware or a specific application. Engineers use different levels for different stages of development. At an early stage, you need to see everything in order to catch small bugs. At the release stage, only critical errors are left so as not to overload the device.
Hierarchy of logging levels in Android
The logging system in Android is built on a strict hierarchical ladder. Each level includes all messages from levels above it in importance. Understanding this structure is critical to properly setting up a filter in debugging tools such as ADB or third-party log readers.
The lowest level is VERBOSE. Absolutely all information goes here, including debugging messages, which are often understandable only to the author of the code. Next comes DEBUG, intended for debugging the operation of algorithms. What follows INFO is informative messages about the normal operation of the app. Above are warnings WARN and errors ERROR. The top of the pyramid is the level ASSERT, which records fatal failures, after which the process usually stops working.
If you are looking for the reason for the game crashing, set the filter to the WARN level or higher. This will sift out thousands of lines about loading textures and leave only messages about problems.
Here is what a complete table of levels looks like with their numeric values, which are used on the command line:
| Level | Value | Description | Color in Logcat |
|---|---|---|---|
| VERBOSE | 2 | All possible information, maximum detail | Gray |
| DEBUG | 3 | Debugging information for developers | Blue |
| INFO | 4 | Regular progress information messages | Green |
| WARN | 5 | Warnings about potential problems | Orange |
| ERROR | 6 | Errors that prevent the operation from being completed | Red |
The choice of a specific level depends on your goal. If you are trying to understand why an application is taking a long time to load, the level INFO will show the loading time of each module. If the application simply closes on startup, you need level ERRORto see the exception code.
Where to find logging settings on a smartphone
In the standard interface of a regular user, hidden logging settings are often not available. However, you can access them through the “For Developers” menu. To activate this section, you need to go to Settings → About phone and quickly click 7 times on the “Build number” item. After this, a new section will appear in the main menu.
Inside the menu for developers, look for an item related to logging. On different firmware it may be called differently: “Log buffer size”, “Logger settings” or “Log detail level”. In some shells, for example on the base MIUI or OneUI, these settings may be hidden deeper or require entering special codes into the engineering menu.
- 📱 Go to
Settings → System → For Developers. - 🔍 Find the "Debugging" or "Monitoring" section.
- ⚙️ Select "Log Buffer Size" or "Logging Level".
- 📝 Set the desired value (usually from 64K to 16M).
It is worth noting that Changing the buffer size does not change the filtering level (Verbose/Error), but it does affect how much history is stored in memory. The small buffer is quickly overwritten by new events, and you may not have time to read the reason for the old error.
⚠️ Attention: The interface of the “For Developers” menu may differ depending on the version of Android and the device manufacturer. If you do not see the necessary items, perhaps your firmware restricts access to these parameters for ordinary users.
Secret codes for the engineering menu
On some devices, access to extended logs can be obtained by dialing numbers in the dialer. Try entering ##2846579## (for Huawei/Honor) or #0# (for Samsung). Be careful: changing settings in the engineering menu may lead to unstable operation of the modem or sensor.
Using ADB to manage logs
For professional work with logs, the most powerful tool is Android Debug Bridge (ADB). This is a command line utility that allows you to control the device from your computer. Through ADB, you can not only view logs in real time, but also forcefully change the logging level for specific processes or tags.
To get started, connect your smartphone to a PC with USB debugging enabled. The main command for viewing logs is adb logcat. By default, it displays everything, which can be inconvenient. To filter the output, a special syntax is used after the command.
adb logcat *:EThis command will set the global filter to level ERROR or higher for all tags. The asterisk symbol represents “all tags” and the letter E represents the error level. You can combine levels for different system components. For example, if you want to see debugging only for the application WhatsApp, and only errors for the rest of the system, the command will look more complicated.
☑️ Preparing to work with ADB
You can also clear the log buffer via ADB if it is full and interferes with the analysis. To do this, use the command adb logcat -c. It is useful to do this before reproducing the bug, so that only information related to a specific test remains in the logs.
Analysis of logs: how to read and understand entries
Viewing raw log data can frighten an unprepared user with an abundance of incomprehensible symbols and numbers. Each line of the log has a strict structure. It typically contains a timestamp, a process identifier (PID), a thread identifier (TID), a tag (Tag), and the message itself.
Tag is a short name that the developer assigns to the source of the message. For example, the tag ActivityManager indicates that the message concerns application management, and WifiStateMachine refers to the operation of the wireless network. Understanding tags helps you quickly cut out unnecessary information.
When analyzing a problem, look for lines marked as Exception or Crash. They are often immediately followed by a “stack trace”—a list of functions that were running at the time of the failure. The topmost line in this list usually indicates the exact place in the code where the error occurred.
- 🕒 Pay attention to the timing: match the moment of the failure with your actions.
- 🏷️ Look for tags associated with the problematic application (often containing the name of the package).
- 🔴 Focus on lines with ERROR and FATAL levels.
Do not ignore warnings WARN. Although they do not lead to an immediate crash, they can indicate low memory, overheating, or network problems, which together lead to system instability.
The main difficulty in analyzing logs is not in reading the text, but in the ability to separate the effect from the cause. An error in one module is often just a reaction to a failure in another, deeper process.
Performance issues and privacy
Enabling detailed logging on a permanent basis is not recommended for everyday use. As mentioned earlier, recording every system action puts a strain on the memory controller and processor. On older or budget smartphone models, this can lead to noticeable interface freezes.
In addition, there is the aspect of digital hygiene. Level logs DEBUG or VERBOSE sometimes can contain sensitive data: authorization tokens, parts of passwords, or geolocation tags. If you provide a log file to a developer for analysis, make sure that it does not contain personal information.
Some malware may try to read system logs to find out what applications you use and what errors occur in them. Therefore, in the security settings of modern versions Android access to reading logs by third-party applications is often limited or requires explicit user permission.
⚠️ Attention: Never publish complete log files (especially those containing memory dumps) in open sources or on forums without first clearing them. They may contain unique information about your device and accounts.
Frequently asked questions (FAQ)
Is it possible to completely disable logging on Android?
It is almost impossible to completely disable system logging without rebuilding the kernel or obtaining root access, since it is critical for the operation of many system services. However, you can minimize its impact by setting a high filtering level or a small buffer size through the developer settings.
Why are there many lines in the logs in an incomprehensible language?
Most of the logs are intended for developers and contain technical jargon, variable names and references to lines of code. For the average user, this data does not carry any meaning. Focus only on messages marked ERROR or those written in clear language.
Does the log level affect the speed of the Internet?
The log level itself does not affect the speed of the Internet connection. However, if network packet logging is enabled at a low level (VERBOSE), the processor will be busy processing these records, which can indirectly slow down other applications, including the browser.
Where are the log files saved after a reboot?
By default, the log buffer (logcat) is stored in RAM and is cleared when the device is rebooted. To save the logs forever, you need to export them to a file via ADB or a special application before turning off the phone.
Is it safe to send logs to the application developer?
In most cases, it is safe if you did not enter passwords or payment information at the time of collecting the logs. However, before sending, it is recommended to open the file in a text editor and remove lines containing personal data or access tokens.