Android phones can last for years, but sooner or later strange problems start to appear with the battery, screen, sensors, or connections. which aren't always visible to the naked eye. And if the phone has been through several hands, relying solely on feel is like playing the lottery: you could end up paying more for a device that's been tampered with without even knowing it.
The most sensible way to clear up any doubts is to use hardware diagnostic apps and verification toolsWith these tools, you can perform everything from a quick check before buying or selling a used phone to advanced tests of performance, battery life, and the overall health of all components. In the following sections, you'll see in detail what they check, how to access hidden Android menus, and which are the best free and professional apps to extract this information.
What do diagnostic tests on Android actually do?
A diagnostic test on Android works like a complete MOT test for your smartphone's hardware.The app runs various tests to check if the screen is responding properly, if the speakers sound as they should, if the battery is holding a charge, if the sensors are reporting consistent values, and if the WiFi and mobile data connectivity is working. Bluetooth or GPS is up to the task.
This type of review is key when buying or selling a used mobile phone on platforms like Wallapop, Milanuncios, eBay or similar sites.Because it allows you to demonstrate, with objective data, the state of the device. It's also very useful when you notice strange behavior—random restarts, audio cutouts, touch glitches, a GPS that won't fix your location—and you want to know if the problem is hardware or software-related.
A good diagnosis can reveal everything from how much usable capacity the battery actually has left and why it's draining so quicklyThis includes issues such as dead pixels on the panel, proximity sensor problems, memory errors, WiFi or Bluetooth antenna failures, or even replaced components that are not original from the manufacturer (non-OEM).
In addition to detecting specific faults, many diagnostic apps allow you to monitor the phone's health on a daily basis.This is especially interesting if you use your phone for work or play and want to anticipate a possible serious breakdown before it leaves you stranded.
Another important function of some advanced programs is the verification of device authenticity.This type of check verifies whether the screen, cameras, fingerprint button, battery, and motherboard are original (OEM) or have been replaced with generic parts. In the secondhand market, this makes a difference, because non-original parts are usually of lower quality and reduce the phone's value.
Diagnostics without installing apps: secret codes and built-in tools
Before you start downloading apps, it's worth trying the diagnostic options provided by the system itself or the manufacturer.Many Android phones include hidden menus and pre-installed utilities that allow you to perform a fairly complete check without installing anything.
The most well-known way to access these menus is through the so-called “secret codes"from the telephone dialerBy entering special combinations, the system opens internal test panels reserved for technical service, but which you can also use with care.
- Code *#*#4636#*#*On many Android devices, it displays advanced information about the phone, usage statistics, battery, and network.
- *#0*# code on Samsung: opens a complete diagnostic menu with tests for screen, colors, vibration, sensors, speakers, camera and more.
- Xiaomi codes like *#*#6484#*#* or *#*#64663#*#*They activate a factory test mode with guided tests for buttons, cameras, vibration, sensors, connectivity, etc.
In other brands, the diagnosis is done from pre-installed appsMotorola, for example, includes the Device Help application, which offers a "Device Diagnostics" section and specific tests for battery, audio, cameras, connectivity, and touchscreen.
Huawei hides a tool called HwMMTestThis can be accessed from Settings > Applications if you enable the option to view all system apps. From there, you can launch a guided hardware test, although it usually requires the battery level to be between a minimum and maximum percentage (for example, between 55% and 80%) and may even require a restart in a special mode.
Things are a little different with Google Pixel phones.There isn't a single, clear diagnostic app, and the secret codes don't always work the same way on all models. In these cases, users usually turn to official support and the Pixel help forums, where self-help workflows are outlined based on the problem (screen, battery, connectivity, etc.), and where the IMEI number and Google account are used for some checks.
These native systems are perfect for an initial filtering of major faults without installing anything.However, they have clear limitations: the menus are technical, some operators disable the codes, and they generally don't generate nice, shareable reports like specialized apps do.
The best Android apps for hardware diagnostics
When you want more than just a hidden menu and are looking for clear reports, guided tests, and highly detailed dataYou'll need to install specific applications. Below is a selection of the most comprehensive and popular tools based on comparisons, reviews, and technical documentation from leading specialized websites.
TestM: a quick and easy-to-understand diagnostic tool for anyone
TestM is one of the most user-friendly apps for those who simply want to know "if their phone is working properly or not" without any complications.It organizes the checks into six main blocks: screen, connection, sensors, hardware, sound, and camera.
In just a few minutes you can launch up to 19 different testsThe app includes color tests to detect dead pixels, touch screen checks, and tests on speakers, microphones, physical buttons, vibration, basic sensors, etc. It guides you with simple instructions like "tap here," "swipe there," or "speak into the microphone."
Its strength lies in the fact that it doesn't just display technical data.After each test, it clearly indicates whether the component has passed or if it has detected any problems, providing easy-to-understand recommendations. Finally, it generates a report that you can save or share via messaging or email—very useful if you're going to sell the phone or want to show it to a technician.
Phone Doctor Plus: Over 40 hardware and system tests
Phone Doctor Plus takes things to the next level, offering a near-professional "medical check-up" without requiring expertise.It includes more than 40 types of automatic tests to locate faults in the screen, camera, microphones, speakers, RAM, storage, sensors, mobile connectivity, WiFi, Bluetooth and much more.
In addition to one-off tests, Phone Doctor Plus allows you to monitor hardware, battery, and memory usage on a daily basis.It records the battery's actual capacity and charge cycles, so you can see how it degrades over time and decide if it's worth replacing.
Another interesting extra is the control of data consumptionThis app helps you avoid unexpected charges by monitoring your mobile network usage. All of this makes it especially useful if you suspect your battery isn't performing as well as it used to or if you're experiencing intermittent problems that are difficult to detect with other tools.
Dr.Fone (Phone Verification): Focus on overall device health
Dr.Fone is a suite well known for its ability to manage, transfer, and recover dataHowever, the package includes a specific "Phone Verification" module that acts as a diagnostic tool for the phone's hardware and overall condition.
This function thoroughly analyzes battery, RAM, internal storage, temperature, and charging cycles.This generates a detailed report with key health indicators. It's very useful for assessing whether a phone is still functional or if, when it comes to selling it, it can still be considered in good condition.
In addition, Dr.Fone helps to pinpoint performance bottlenecks such as lack of available memory, frequent overheating, or a severely worn battery that hinders daily life and makes even simple tasks feel burdensome.
Device Info HW: Ultra-detailed X-ray of all components
Device Info HW is designed for those who want to know exactly what's inside their Android device.The app attempts to identify each hardware component individually: LCD panel, touch screen, cameras, sensors, memory chips, flash storage, audio, NFC, charger, WiFi, Bluetooth, and battery.
In many devices, it even displays the specific model of the panel, the touchscreen, and various sensors.This is very useful for technicians, ROM developers, kernel cooks, or simply curious users who want to know the "DNA" of their mobile phone.
It includes practical tests such as multi-touch verification, screen color test, sensor test or download speed measurementIf the device is rooted, Device Info HW can read even more sensitive information, such as flash memory details or internal driver lists that are partially locked on recent devices.
The PRO version adds features designed for advanced and professional useFeatures include: HTML or PDF report generation, permanent dark themes, listing of I2C and SPI devices, partitions, voltage regulators (PMICs), codecs, USB OTG devices, etc. It is also one of the most highly regarded tools for detection. non-original parts or hardware changes after a repair.
Device Info / My Device: Complete data and simple tests
Alongside Device Info HW, there are other "device information" apps, such as My Device – Device info or Device Info by Toralabs., focused on clearly showing all the essential details without overwhelming.
These apps typically cover data about the system-on-a-chip (SoC), RAM, storage, battery, sensors, and Android version., adding in many cases small tests to check elements such as speaker, microphone, flashlight, light sensor, accelerometer, WiFi, Bluetooth, fingerprint reader, volume, temperature or camera.
The beauty of it is that they combine technical specifications with diagnostic functions.In a single app, you can find out what processor and how much RAM your phone has, and at the same time run basic tests to tell you if something isn't working perfectly, including displaying battery health and wear levels.
Test Your Android / Test your Android
Test Your Android, also known as “Prueba tu Android” in Spanish, is geared towards users who want a quick check of key components without getting too complicated. The interface is simple and groups different tests into easily recognizable icons.
It allows you to test the camera, speakers, microphone, fingerprint reader, multi-touch panel, screen colors, GPS, compass, and light, pressure, or temperature sensors.among others. You just have to tap on the test you're interested in and follow the app's instructions.
Its strong point is how easy it is to use, even for people with little technical knowledge.On the other hand, some versions display quite a few ads, and the defective pixel detection mode can be somewhat slow, plus it doesn't always generate exportable reports.
Android Hardware Info
Droid Hardware Info focuses on providing an organized and clear overview of device specifications.The information is grouped into tabs such as device, system, memory, camera, battery, and sensors, making it easy to locate each piece of data.
You'll find details about the SoC, the exact phone model, screen resolution and size, storage capacity, and battery temperature and voltage., list of sensors present, etc. Although it is not the app with the most active tests, it works very well as a quick reference tool.
One of its great strengths is the ability to export all the information to save it as a report. This is very convenient if you repair mobile phones, if you want to include the data sheet when selling the device, or if you need to send it to a technician without having to manually enter all the information.
CPU-Z for Android
CPU-Z is a classic computer tool that also has an Android version, highly valued for thoroughly checking the processor and sensors.Its starting point is the precise identification of the CPU and its behavior.
The app displays model, number of cores, frequency of each cluster, architecture, CPU load level, as well as information on RAM, resolution, manufacturer, and Android version.In the battery tab you will see level, temperature, voltage and general status, and in sensors all those present are listed with their real-time values.
It's not a tool that "tells you if something is right or wrong" with simple messages.Rather, it displays raw data, making it ideal for users with a minimum of technical knowledge who want to check if the specifications match those promised or compare performance between devices.
AIDA64: Comprehensive hardware and software information
AIDA64, inherited from the Windows ecosystem, is probably one of the most complete apps for identifying each component of an Android mobile phone.It's also available for iOS, but on Android it truly shines due to its level of detail.
It can display diagnostic information about the CPU (including real-time frequencies), GPU, RAM and storage, manufacturer, screen dimensions and density, cameras, battery, WiFi and mobile network, IMEI, memory types, and much more.It also lists installed apps, system directories, and present sensors.
Although it does not perform interactive screen or sound tests, its main function is to verify that everything the manufacturer or seller states matches reality.It is widely used to unmask fake mobile phones, manipulated devices, or phones in which parts have been changed without notice.
DevCheck: real-time system monitoring
DevCheck is designed for those who want to see how the mobile hardware performs at any given moment.Beyond a simple static list of specifications, its Material Design-based interface displays real-time graphics and statistics.
You can check CPU and GPU usage and frequency, battery consumption and temperature, used and free memory, network speed, active sensors, cameras, and operating system versionall with easy-to-read visual panels.
If your device is rooted, DevCheck unlocks even more internal metrics., very valuable for advanced users, developers and those who fine-tune system performance with custom ROMs or modified kernels.
3DMark, PCMark, Geekbench, GFXBench, CPU X and AI Benchmark: performance tests (benchmarks)
In addition to diagnostic apps, there are benchmark tools, designed to measure the raw power of the CPU, GPU, and, in some cases, battery and storage speed.They're not health diagnoses as such, but they do tell you if your phone is performing above or below expectations.
3DMark focuses on graphics and CPU performance in 3D games and heavy workloads.It runs very demanding graphical scenes and then assigns a score that you can compare with other Android devices, as well as iPhone or iPad models, to see if your mobile can keep up with the most powerful games.
PCMark focuses more on everyday tasks such as browsing, editing documents, photos, and video.In addition to measuring performance, it allows you to profile battery life with real-world usage scenarios, analyzing how long the battery lasts when performing different continuous activities.
Geekbench 5 performs CPU and GPU tests in both single-core and multi-core modes.It includes tests related to artificial intelligence and augmented reality. It is cross-platform (Android, iOS, Windows, macOS, Linux) and allows you to upload results to your web browser to share and compare scores between devices.
GFXBench Benchmark is geared towards long-range graphical evaluationIt measures GPU performance and stability with complex 3D effects, on-screen and off-screen tests, support for APIs such as OpenGL or Vulkan, and checks that also take into account temperature and how the device behaves when it heats up.
CPU X is another utility that combines detailed information about CPU, memory, sensors, camera, and internet speed., temperature and battery amperage, in addition to providing extra utilities such as a ruler, bubble level, compass or signal tools, making it a fairly complete all-in-one.
AI Benchmark specializes in measuring the performance of artificial intelligence tasksFacial recognition, image classification, bokeh effect, blemish correction, etc. It runs 46 tests spread across 14 sections and is optimized for chips with NPUs or AI accelerators such as many Dimensity, Exynos, Helio, Kirin, or Snapdragon processors.
With these benchmark apps you can check if your Android is still performing at the expected level compared to other models And whether the jump to a new phone will be worth it in terms of raw power. Of course, when buying, it's wise to combine this information with actual hardware health checks. Also, check out our selection of best benchmarking apps to compare scores.
Professional diagnostic and certification software for businesses
When second-hand shops, refurbishment companies, or wholesalers that process hundreds of mobile phones come into play, free apps fall short.In these cases, professional solutions such as Phonecheck are used, designed to automate diagnostics and certify devices.
Phonecheck offers automated scans of up to 80 checkpoints over the phone.WiFi, Bluetooth, GPS, screen, sensors, cameras, speakers, microphones, physical buttons, vibration, battery, mobile connectivity, and much more. The goal is to have standardized and repeatable quality control for all devices.
One of its great advantages is the generation of very detailed certification reportsThese reports include brand, model, IMEI number, production and sales dates, warranty status, possible carrier locks, whether the device is reported as lost or stolen, and results of all hardware tests.
Phonecheck also verifies the authenticity of key components such as screen, cameras, battery, motherboard, or fingerprint button, marking any that are not OEM. This is crucial in the second-hand market, where generic replacements are increasingly common and affect both economic value and reliability.
Another pillar of these platforms is certified secure data erasureWith standards like ADISA, we ensure that mobile phones are delivered completely clean of personal information before being resold. This protects the previous owner and improves buyer confidence.
The results of each scan are stored in the cloud and can be exported as PDF reports or even as physical labels affixed to the device, making it easier for the store to show that the mobile phone has passed a recognized certification process and better justify its price.
Hardware problems that these tests often uncover
When running full diagnostics, it is not uncommon to find faults that the user had not detected or that they believed were "system issues".Some patterns are repeated quite frequently on older Android phones.
A degraded or uncalibrated battery is one of the most common problemsThe actual capacity drops far below the original, and the phone shuts down with seemingly high percentages, jumps from one value to another strangely, or drops very quickly as soon as it starts to be used.
Audio and vibration failures are also common.: microphones that stop capturing the voice well, speakers that distort or sound very low, defective call headset or vibration motors that work intermittently, often due to impacts, humidity or wear.
Touchscreens frequently experience dead pixels, unresponsive areas, or panel miscalibration.At first glance they may go unnoticed, but a dedicated panel and multitouch test brings them to light, allowing you to assess whether it's time to replace the screen or negotiate the price of a used device.
The sensors also cause problems: proximity, gyroscope, accelerometer or ambient light sensor can report inconsistent readings or simply not work, causing problems with screen turning off during calls, with automatic rotation, or with adaptive brightness.
Finally, it's not uncommon to find faults in WiFi, Bluetooth, and GPS. These issues affect everyday experiences such as hands-free calls, online gaming, map navigation, and the use of connected wearables. Diagnostics help distinguish between a hardware problem (damaged antenna, damaged module) and a simple software bug.
How to choose the best diagnostic app for your case
With all the available apps, the important thing is to choose the one that fits your skill level and what you really need.There's no point in installing a professional tool if you only want to check that the screen doesn't have dead pixels, nor is it worth sticking with a basic app if you manage dozens of phones.
At a minimum, make sure the application covers the main areas of the hardware.: battery, screen, audio, cameras, basic sensors, RAM, internal storage and wireless connectivity, and, if possible, physical buttons and vibration.
The app's reliability and reputation are also keyTake a look at the ratings on Google Play, the frequency of updates, and developer support. Android changes quickly, and a tool that isn't kept up to date may stop displaying data or fail on newer phones.
If you need to use the results for sales, repairs, or appraisals, look for apps that allow you to export or share reports. in PDF, HTML, or other formats. And if you manage many devices, automating and running tests in batches will save you a tremendous amount of time.
The design and clarity of the interface are also not a minor detailThe best tools combine technical information with simple explanations and step-by-step instructions. If an app bombards you with numbers you don't understand, you won't get much use out of it, no matter how powerful it is.
Who should use hardware diagnostic tools on Android
The great thing about the Android ecosystem is that today there are tools for all types of users, from the most novice to the laboratory technician.It is important to be clear about which profiles benefit most from these diagnoses.
If you buy second-hand mobile phones, asking the seller for a recent test with one of the apps mentioned is almost mandatory.A report from TestM, Phone Doctor Plus, Device Info HW or AIDA64, for example, gives much more confidence than a simple "it works perfectly, I swear".
If you're selling your own device, including an up-to-date diagnostic report with the ad helps you better justify the price.This reduces future arguments and sets you apart from other generic ads. In a saturated market, this transparency is highly valued.
For technicians, shops, and refurbishment businesses, the use of professional certification software like Phonecheck has become almost indispensable.It allows you to document each device, automate testing, ensure secure data erasure, and deliver clear reports to both the end customer and other intermediaries.
And, of course, they are also ideal tools for curious users or technology enthusiasts. They want to know what components their mobile phone has, compare performance, monitor temperatures while playing games, or check if the device is still performing like it did on day one or is ready for retirement.
Having good diagnostic apps and knowing how to at least minimally interpret their results makes the difference between going in blind when something goes wrong and being able to make decisions with data in hand.From avoiding a bad purchase of a used mobile phone, to detecting a battery or screen problem in time before the repair becomes more expensive than it should be.
