What is a MicroSD Card?
A microSD card, also known as a microSDHC or microSDXC card, is a type of removable flash memory card used for storing photos, videos, music, documents and other files on small, portable devices such as smartphones, tablets, and action cameras. MicroSD cards are a miniature version of the standard SD card and are about the size of a fingernail.
Some common uses of microSD cards include expanding storage on Android smartphones, storing media files on drones and dash cams, adding memory to handheld gaming systems like the Nintendo Switch, and running operating systems on devices like the Raspberry Pi. They allow you to add more storage space to your device for apps, media files, and more.
MicroSD cards come in different storage capacities, typically ranging from 8GB to 1TB. Some of the most common sizes are:
The larger the capacity, the more data you can store on the card. High capacity cards like 128GB+ are useful for storing lots of HD video or high resolution photos.
Does Formatting a MicroSD Card Erase It?
Formatting refers to the initialization and reorganization of a data storage device, such as a microSD card. When a microSD card is formatted, the file system structure on the card is rebuilt, deleting all of the existing data and preparing the card for new data to be written. At a basic level, formatting erases all data currently stored on the card and allows it to be reused as if it were blank (Source 1).
Formatting a microSD card is different than simply deleting files or using the recycle bin on a computer. When files are deleted, only the directory references to those files are removed, while the actual data remains on the card until it is overwritten by new data. Formatting erases all of the actual data on the card, reinitializing the file system so it appears blank to the operating system (Source 2).
In summary, formatting a microSD card erases all current data by rebuilding the file system structure. It is more complete than deleting individual files and leaves the card blank and ready to be reused.
Why Format a MicroSD Card?
There are a few key reasons you may want to format your microSD card:
To erase all data before donating or selling the card. Formatting wipes all data from the card, ensuring no personal information remains if you plan to give the card to someone else. This is an important step for protecting your privacy.
To reset the file system after corruption. If your card becomes corrupted or unreadable by your device, formatting it can wipe the slate clean and restore proper functionality. Corruption can happen from sudden removal while writing data, viruses, or general wear and tear.
To improve performance if the card is acting slow. Over time, small inefficiencies in file storage can build up and degrade the card’s speed. Formatting clears out this clutter and restores the card to its optimal state. Periodically formatting your frequently used cards can maintain peak performance.
How to Format a MicroSD Card
Formatting a microSD card can be done using the built-in formatting tool found on many devices like cameras, smartphones, and tablets. It can also be formatted using a dedicated SD card formatting application on a computer.
To format a microSD card using a camera or smartphone:
- Locate the settings menu and look for an option to format or delete data.
- Select the microSD card when prompted.
- Choose to format the card and select OK to confirm.
On a Windows computer, you can use the SD Card Formatter app from the SD Association to format microSD cards. To use this formatter:
- Download and install the SD Card Formatter on your Windows PC.
- Insert the microSD card into your computer’s card reader.
- Open the SD Card Formatter app and select the drive letter for your microSD card.
- Check the Quick Format box and click Format to start formatting the card.
On Mac computers, the built-in Disk Utility app can be used to format SD cards. To use Disk Utility:
- Connect the microSD card to your Mac.
- Open Disk Utility.
- Select the microSD card on the left side.
- Click Erase at the top.
- Give the card a name and select a format like MS-DOS (FAT).
- Click Erase to confirm and format the card.
Following device or computer formatting instructions carefully will allow you to quickly format a microSD card and prepare it for reuse.
Recovering Data After Formatting
If you accidentally format a microSD card, there may still be a chance to recover your lost data. Specialized data recovery software like Disk Drill  can help scan a formatted card and restore deleted files. The success rate depends on several factors:
– How much new data has been written after formatting – the less data written, the better the chances.
– What file types were stored – simpler formats like JPEGs have higher recovery rates.
– Speed of the SD card – faster cards make data recovery more difficult.
To maximize the chances of recovering data after formatting a card:
– Stop using the card immediately to prevent overwriting files.
– Use data recovery software as soon as possible after formatting.
– Scan the card before attempting to save new files.
– Try multiple data recovery tools if the first one fails.
With the right software and quick action, there’s a good possibility of getting back lost files and photos from a freshly formatted microSD card . However, the longer you use the card after formatting, the lower your chances become.
Securely Erasing a MicroSD Card
Simply formatting a microSD card does not securely erase the data. Formatting only removes the address tables so the files are not accessible. The actual data still remains on the card until it is overwritten by new data.
To prevent sensitive data from being recovered, it is important to use software that overwrites the entire card with random data. This is sometimes called a “secure erase.”
Some options for securely erasing a microSD card include:
– Using the secure erase tool in Wondershare Recoverit. This overwrites the entire card space with 0s to permanently erase data.
– Using disk utility tools like EaseUS Disk Wipe that can write random data across the full card multiple times.
– On Android devices, using the ‘Erase SD card’ option in Settings which overwrites data instead of just reformatting.
Securely erasing cards is especially important before recycling, donating or reselling them. It prevents sensitive financial, business or personal data from falling into the wrong hands if someone tries to recover deleted files from the card.
Alternatives to Formatting
Formatting a microSD card is not always necessary to prepare it for reuse. Here are some alternatives to consider before doing a full format:
Just deleting files: If you just want to wipe the files off a card to free up space, you can simply delete the files instead of formatting. This is quicker and prevents loss of data. However, it does not fix any filesystem errors on the card.
Using defragmentation tools: Defragmenting a microSD card can help optimize it by reorganizing files, consolidating free space, and speeding up access times. Defragmentation may resolve some performance issues without needing to erase all data.
Low level vs quick formatting: Full formatting erases the entire card, while quick formatting simply removes the file allocation table. Low level formatting also checks for bad sectors and can repair a corrupted card. Quick formatting is faster but may not fix all issues.
So in many cases, alternatives like deleting files, defragging, or quick formatting can prepare a microSD card for reuse without needing to completely erase it through full formatting. But periodically doing a full format optimizes the card’s performance and clears any filesystem errors.
Preventing SD Card Corruption
There are several best practices you can follow to avoid SD card corruption:
Safely eject the card
Always use the “Safely Remove Hardware” option on your computer or device before removing the card. This ensures any writes are completed before disconnecting the card, reducing the chance of corruption (1). Sudden removal while writing is a common cause of problems.
Avoid excessive heat or moisture
Keep your memory cards away from direct sunlight, water, and high temperatures, as these can damage the card and lead to corruption. Store cards in a cool, dry place when not in use (2).
Handle the card carefully
Be gentle with memory cards, avoiding drops, impacts, bending, or other physical damage. The contacts are fragile. Use a protective case when not inserted in a device (3). Clean contacts gently with a soft cloth if needed.
Following basic precautions like these can significantly reduce your chances of a corrupted card. But it’s still wise to regularly back up your images and files in case problems occur.
Choosing the Right MicroSD Card
There are a few key factors to consider when selecting a microSD card:
Speed Class Ratings
The speed class rating indicates the minimum guaranteed speed that the card can sustain during continuous reads or writes. Common speed classes for microSD cards include:
- Class 2 – Minimum 2MB/s write speed
- Class 4 – Minimum 4MB/s write speed
- Class 10 – Minimum 10MB/s write speed
- UHS Speed Class 1 (U1) – Minimum 10MB/s write speed
- UHS Speed Class 3 (U3) – Minimum 30MB/s write speed
Higher speed class cards allow for faster transfer of photos, videos, and other data. UHS-3 is ideal for 4K video recording. For basic uses like casual photography, Class 10 is sufficient.
MicroSD cards are available in capacities ranging from 2GB to 1TB. The capacity needed depends on your intended use. For example, a 16GB card can store around 4,000 photos or a few hours of HD video. For extensive photo/video needs or installing apps, larger capacities like 128GB+ are recommended.
Look for major brands like SanDisk, Samsung, Sony, Kingston, and Transcend when buying microSD cards. Avoid cheap, generic cards which are less reliable. Check reviews to confirm quality and performance of a card.
Considering these factors will help ensure you select a microSD card adequate for your requirements.
FAQs About MicroSD Cards
Here are some frequently asked questions about microSD cards:
What is the difference between MB, GB, and TB?
MicroSD card capacity is measured in megabytes (MB), gigabytes (GB) and terabytes (TB). 1 GB is equal to 1,000 MB. 1 TB is equal to 1,000 GB. So a 64 GB microSD card can hold 64,000 MB of data.
My microSD card is not working, what should I do?
Here are some tips if your microSD card is not being detected or is not working properly:
- Try taking out the microSD card and reinserting it to make sure it is seated properly.
- Inspect the card and card slot for any dust or debris.
- Try the microSD card in another device to see if the issue is with the card or the device.
- Reformat or “reinitialize” the microSD card using your device settings.
- As a last resort, try a different brand new microSD card.
How can I recover deleted files?
If you accidentally deleted files from your microSD card, stop using the card immediately. Download a data recovery app to your computer and connect the microSD card via adapter. The app may be able to scan the card and recover deleted files, but there are no guarantees.