How can I test my micro SD card?

Quick Overview

There are a few easy ways to test your micro SD card to make sure it is functioning properly before you put important files on it:

  • Physically inspect the card and card contacts for any damage or corrosion.
  • Use your computer’s built-in disk utility to scan for errors.
  • Use a dedicated SD card tester device.
  • Format the card and perform read/write tests using benchmarking software.
  • Take sample photos/videos with your device to verify the card can store files.

Thoroughly testing a new micro SD card can help identify potential issues and ensure your important data will be stored reliably. Continue reading for more detailed steps on how to test your micro SD card.

Physically Inspect the Micro SD Card

The first step in testing a new micro SD card is to physically inspect the card and the metal contacts for any signs of damage or corrosion. Carefully look over both sides of the card and make sure there are no cracked components, dents, scratches, or other physical defects.

Pay particular attention to the metal electrical contacts along the bottom of the card. These small metallic strips transmit data to your device when the card is inserted. If the contacts appear dirty, scratched, or corroded it can affect the connection. Gently clean them with a soft cloth or cotton swab if needed.

A damaged card or dirty/corroded contacts are often the culprit behind connection issues. Performing this quick physical inspection can help identify problems right off the bat before you attempt to use the card.

Scan for Errors Using Your Computer’s Disk Utility

The next test is to insert your micro SD card into your computer’s card reader and scan it for errors using your operating system’s built-in disk utility software. This will analyze the card for bad sectors, file system issues, and other problems.

On Windows:

– Open File Explorer and right-click on the drive letter assigned to your SD card. Select “Properties” then open the “Tools” tab. Click “Check” to scan for file system errors.

– Alternatively, open a Command Prompt window as Administrator and run “CHKDSK E: /f” where “E:” is replaced by your drive letter.

On Mac OS:

– Launch Disk Utility, select your SD card volume, and click “First Aid”. This will scan and attempt to repair any issues.

– If any errors are reported during the scan, the card likely has defects and should be replaced. Even if no errors are found, it is still worthwhile running this disk check.

Use a Dedicated SD Card Tester

For more thorough testing, consider using a dedicated SD card tester device. These are relatively inexpensive and provide advanced diagnostics and benchmarking that go beyond your computer’s built-in tools.

Dedicated testers can perform read/write speed testing, evaluate random vs sequential performance, test with custom file sizes, and benchmark sustained write operations. This helps identify real-world performance issues.

Look for testers that support the latest standards – UHS-I, UHS-II, UHS-III, and A2 App Performance. Models from Anker, Atolla, and HYi are good options that provide valuable diagnostics.

Key SD Card Tester Capabilities:

  • Read and write speed benchmarking
  • Sustained write testing to check for performance drops
  • 4K random read/write testing
  • Assess max sequential write speed for different file sizes
  • Stress testing by writing the full card capacity
  • Interface compliance testing
  • Support for latest performance standards

Using a dedicated SD card tester provides more robust analytics to assess your card’s true level of performance and ensure it is up to par.

Format and Benchmark with Software

In addition to physical testers, there are various software tools available to format an SD card and benchmark its capabilities. Here are some top options:

BlackMagic Disk Speed Test

Available free for MacOS, BlackMagic benchmarks read/write speeds using various file sizes up to 5GB. It also measures maximum throughput so you can verify your card meets its advertised specs.

F3 (Fight Flash Fraud)

F3 is a free, open source program available for Windows and Linux. It tests read/write performance and scans for bad sectors. Use it to perform sustained write testing to check for consistency.


H2testw is a commonly recommended SD card benchmarking utility for Windows users. It writes test patterns across the full card capacity then verifies them to identify issues.


This dedicated SD card formatting tool from the SD Association provides a standard way to prep cards. Use it before benchmarking to establish the proper file system.

Formatting the card and running benchmarks with these types of utilities will provide more insight compared to just a quick error scan. Look for performance inconsistencies and any read/write failures.

Take Sample Photos and Videos

The final way to test your micro SD card is to insert it into your camera, phone, drone, or other device and use it to take sample photos and video. This gives you a real-world usage test.

Verify that files are saving properly to the card and that there are no read/write errors or crashes when using the card in its intended application. Try recording video for extended periods to simulate important footage.

Testing the card in the device you intend to use it with checks for any compatibility issues and ensures the card’s stated minimum write/read speeds meet your device requirements.


Thoroughly testing a new micro SD card using the methods above will help confirm the card is functioning properly before you trust it with important photos, videos, files, and other data.

Physically inspecting, scanning for errors with disk utilities, using dedicated testers, benchmarking with software, and test usage in your device will identify any reliability or performance issues that could impact your experience. Taking the time to fully evaluate and prepare your card will give you confidence it can handle your storage needs.

Frequently Asked Questions

What are some signs of a faulty SD card?

Some common signs of a faulty SD card include:

– Slow or inconsistent read/write speeds
– Files not saving properly or appearing corrupted
– “Card cannot be read” errors
– Card is recognized but shows 0 bytes capacity
– Crashes or freezes when card is in use
– Visible damage to card contacts or components

Can I fix a corrupted SD card?

It depends on the type of corruption. Running the card through your computer’s error checking utilities may fix simple file system issues. But any physical damage to memory chips or internal components cannot be repaired – the card will need replacement.

How do I check SD card speed?

Use a dedicated SD card tester device or benchmarking software like BlackMagic Disk Speed Test to measure the read and write speeds with different file sizes. Compare results to the card’s advertised specs.

What is the best software to test an SD Card?

Some top options are BlackMagic Disk Speed Test for Mac/Windows, F3 for Windows/Linux, H2testw for Windows, and SDFormatter to correctly format cards before testing. Dedicated hardware testers provide the most thorough diagnostics.

Can you test an SD card with your phone?

Yes, you can test a micro SD card with your phone by inserting it and attempting to take photos, videos, and save files. Check for any read/write errors and verify files are not corrupted. Use it normally to check real-world performance.

How long does an SD card last?

Most SD cards can withstand thousands of read/write cycles and last for 3-5 years or more with normal usage. Higher endurance cards rated for intense workloads may last 5-10 years. Proper handling and maintenance will maximize lifespan.