Owning modern Xiaomi technology often requires knowing the device’s specifications, including its date of market launch, and users face this question when buying a used gadget, making a warranty, or simply out of curiosity about the history of their gadget. Unlike computers where the BIOS build date is visible immediately, in mobile devices this information is sometimes hidden in the back of the system or encrypted in serial numbers.
Determining the age of a device is not just a matter of curiosity, it's an important part of diagnostics. Knowing the exact year of release will help you predict the approximate battery life, understand whether security updates are relevant to your model, and whether you should expect a new version of MIUI or HyperOS to arrive. There are several proven methods to get this data without using sophisticated software.
In this article, we will take a look at all the options available, from simply inspecting the box to using the engineering menu, and learn how to read the manufacturer’s codes and understand how to interpret the data from the system logs, and this knowledge will help you avoid buying an old refurbished device that is being passed off as a new one and correctly estimate the market value of your smartphone.
The easiest and most obvious way to know the date of production is to look carefully at the box from under the device. Electronics manufacturers including Xiaomi, Redmi and POCO are required to affix the technical marking on the package. Usually, a white barcode sticker with the serial number (S/N) and the date of manufacture is placed on the back or side of the box.
The date format can vary depending on the region of sale and the year of release of the box itself. Often found standard YYYY-MM (year-month) or DD/MM/YYYY. If you buy a device from hand, be sure to require the seller original packaging, as it is the only physical carrier of information about the "birth" of the phone that can not be changed software.
⚠️ Note: If the date sticker on the box is re-adhesive, has wipe marks, or the font differs from the main text of the package, this may indicate that the device has been repaired or is restored (Refurbished).
Also worth paying attention to the integrity of the seals. If the box is opened, the data on it may not match the insides of the device. In rare cases, especially when resold through third hands, the package may be lost, then you will have to resort to software methods for verifying identities.
Checking the date through the engineering menu and USSD-code
The Android operating system, which runs MIUI and HyperOS shells, provides access to a hidden engineering menu, a powerful diagnostic tool that allows you to see the deepest parameters of the system, including the dates of calibration of modules and firmware assembly.
Enter the combination ##6484## or ##4636## in the dialer. Once you enter the last digit or character, the menu should open automatically. If this does not happen, your firmware version or regional modification may block access to these features. From the list that opens, select Version Information or Phoenix Information.
What if the code doesn't work?
If the standard codes do not activate the menu, try entering the *#06# code to check. IMEI. In some cases, the engineering menu is only available after installing a special dealer application or through the ADB-commands, but this requires root rights or an unlocked bootloader.> Inside the menu, look for lines that say "Build Date," "Compile Time," or "Manufacture Date." Note that the firmware build date is always later than the physical production date of the phone's hardware, the difference is usually 2 to 6 weeks. This time is needed for the installation of the OS, testing and packaging of the device in the factory. ☑️ Actions during verification through the engineering menu Open the application "Phone" Enter the code ##6484##Select Version Information Compare Build Date to Purchase Date: 0 / 4 This is the most accurate method for determining the age of the software that is installed on the device out of the box. However, if the phone is reflashed, this data can be changed, so to determine the real age of the hardware, it is better to use a combination of methods. Analysis of the serial number and IMEI Code Serial number (S/N) and IMEI-The code contains encrypted information about the manufacturer, model and release date, and it is difficult to decrypt them manually, because Xiaomi does not have a single public date encoding standard that would remain unchanged for decades. Usually the first few symbols S/N They're the ones that point to the manufacturing plant, and the numbers that follow are often the year and week of production. 5-and 6-The symbols may indicate the year (19 — 2019, 20 — 2020 For accurate decryption, it is better to use online services specializing in the verification of Xiaomi equipment. Data type Where to find What shows Accuracy Serial number (S/N) On the box, in the settings, under the battery Plant, batch, approximate date High IMEI Code On the box, on the menu *#06# Unique. ID Average (requires a base) Software Assembly Date Engineering menu Compilation Date Firmware Average (later production) Warranty card Documents from the seller Start date Guarantee Maximum There are specialized sites where you can enter IMEI or S/N, to get a report on the device. Such a report often gives the exact date of activation or first registration on the network, which is actually the date of the start of use of the smartphone, which is especially useful when buying used equipment, when the seller claims that the phone “almost never used". ⚠️ Note: Never give the full data IMEI and S/N This data can be used to clone a device or block it remotely. If you do not want to mess with codes and tables, you can use third-party applications from the Google Play store. CPU-Z, AIDA64 or Device Info HW They collect all the information that's available about the system and output it in a readable way, and these ulits can read data from system files that the average user can't access without root permissions. Once you install this app, start scanning your device, and you're interested in the "Device" or "System" tab, which may include the "Build Date" or "Android Build" field. While this again brings us back to the software build date, when combined with information about the processor model and Android version, it’s easy to calculate the year a smartphone was released. For example, if the phone is Android 10 out of the box, it’s unlikely to be released in 2026. The advantage of such applications is their versatility - they work on any model, whether it is the old Redmi Note or the latest flagship of the Xiaomi 14 series. In addition, they will show the real screen resolution, the number of cores and the temperature of the sensors, which is useful for the overall assessment of the condition of the gadget. 💡When installing diagnostic applications, pay attention to permissions. Good software doesn't need access to your contacts or microphone to show you specifications. Note that some of the data in such programs may be misread on heavily modified firmware or custom Android builds. In such cases, it is better to double-check the information through official channels or service centers. The official website and verification by warranty The most reliable source of information is the company Xiaomi. On the official website there is a support section where the serial number or IMEI can check the status of the warranty. The date of the end of warranty service is usually counted from the date of sale or production date plus one year (or two, depending on the region and shares). Go to the official support portal, find the section "Vertailing warranty" (Warranty status is not found). If the warranty has expired, the system often shows the expiration date, subtracting the warranty date, gives you an approximate release or sale time, and it also lets you know if the device is a grey import or was intended for your region. The official database contains information about all legally produced devices, which eliminates the possibility of forging model data. 💡Official inspection of IMEI The only way to know if a device is being stolen or locked by a serial number is to go to a manufacturer's website, and if a site makes an error or says "Not found," that's an alarm. It may be that the device was illegally assembled, the data in the database is damaged or the number is broken, in which case it is better to refrain from buying or using such a smartphone. Sometimes you don't need to know the exact date of production of a particular instance, you just need to know the year of release of the model. The specifications of smartphones are tied to the year of their announcement. Knowing the model (for example, Redmi Note 10 Pro), you can easily find the date of its presentation on the Internet. Usually, the production of the model begins 1-2 months before the official announcement and continues for 12-18 months. If you see a new sealed phone model that came out 3 years ago, it is likely that it is either a restored device or a device with a long-discharged battery that could degrade during storage. Compare the declared characteristics with a typical 5G phone that is released after the year of 2021. Or the presence of a processor that has ceased to be produced in 2019 It will indicate the actual age of the hardware, even if the box is new. MIUI, It's a little bit of a slack that hasn't been updated in two years, and it might indicate that the device has been in storage for a long time. Modern gadgets usually come with an up-to-date version of the OS or offer an immediate update (FAQ) Can the date in the settings be different from the date in the box? Yes, it can be more often than not. The date in the settings (Build Date) is the date of compilation of the software that is usually on the computer. 1-2 a month after the date of physical production of the device indicated on the box or in the S/N How do you know when the phone is out? If the phone isn't turning on, software is not available. The only option is to look at the sticker on the back cover (if it's not removable, then underneath), the original box or the warranty card with the store stamp. Does the year of release affect the speed of the smartphone? Indirectly, yes. Older models have less performance hardware by modern standards and may not receive security updates and optimizations, which makes heavy applications slower over time. Where to find a serial number if the sticker is erased? Serial number (S/N) Always duplicated in the system. Go to Settings → The phone. → General information will be provided. S/N, It's true that the battery goes bad when the phone's been in storage for a long time. It's true that lithium-ion batteries degrade over time, even when the device is not in use. If the phone is more than 2-3 years old from the date of production, the battery capacity could decrease by 10-20% simply due to chemical aging.