How-To check whether a micro SD or SD card is real or fake


For some unknown reason, SD and micro SD cards are subject to the biggest counterfeiting operations; even with things like PayPal’s buyers’ money back guarantees in place, sellers are still selling fake SD and fake micro SD cards on eBay and even their own websites.

My only guess is, users do not know that they’ve been conned until it’s far too late to get a refund from schemes like PayPal’s buyers’ money back guarantee. Due to the fact that they do not know how to verify or tell whether the SD/micro SD they have purchased is the real deal or not.

In this article, I hope to solve this problem for Windows users, by introducing you to a proven and reliable method to test the authenticity of SD and micro SD cards.

Brief overview of test

There are only two aspects to a SD/micro SD card that make it a fake card:

  1. Card is slower than what is shown on the card (or advertised by the seller)
  2. Card ‘lies’ about its actual storage capacity

Armed with this knowledge, what the software H2testw does is:

  1. Fill up your SD/micro SD card with randomly generated files as fast as it can
  2. Once card is filled, it will check whether the randomly generated files are in good shape (again, as fast as it possibly can)
  3. Displays the test results, informing you of the actual read and write speeds of the card along with its usable capacity

Note 1: Read/write speed is also subject to your card reader’s speed limitations, so ensure you are using a fast card reader for best results as well as reduce the time needed to test the card.

Note 2: At any point, if the card fails due to invalid storage capacity, you will be presented with an error message and the test will stop.


In order to follow this tutorial, you’ll need a Windows-based machine as the software H2testw only supports Windows 2000, XP, Server 2003, Server 2008, Vista, 7, 8, and 10. (A virtual machine with any of the previously listed Windows versions will also work).

You will need to download the testing software H2testw using any of the following links (they all link to the same file):


Step 1

Change the the language by selecting English radio button (unless you understand German). Then click Select target button. Using the selection dialog, select the SD/micro SD card from your list of drive options.

Figure 1. Initial screen before selecting a target to test.

Step 2

Leave all the other settings alone and click on the Write + Verify button to begin the testing process.

Note 3: If you already have some files on the card, you will get a warning informing you that you are not testing the entire capacity of the card – this is fine. However, if you want to be pedantic, you can navigate to the card in Windows Explorer and delete the files; then click the Refresh button in H2testw.

Figure 2. Screen after test target selected.

Step 3

Once the testing process has begin, you will see a progress window, showing you the progress and information about the write/read speed, depending on the stage of the overall test.

Figure 3. Start of testing 64GB Samsung pro micro SD card.

Step 4

Once the test is complete, you will get a summary of the results in the progress window.

To tell whether the card is a fake or not, look the actual read/write speed achieved and the capacity the H2testw software could test.

Note 4: H2testw does not automatically delete the files it creates on the card after the test has completed. Easiest way is to format the card once you’re done.

Figure 4. Result of testing 64GB Samsung pro micro SD card.

Sample SD card test result

Testing a SD card is no different to testing a micro SD card, just follow the steps above. Below is a sample test run of a PNY 64GB SD card.

Figure 5. Testing 64GB PNY SD card in progress.
Figure 6. Result of testing 64GB PNY card.

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