11 Freeware To Detect Fake USB Flash Drives, SD Cards And SSD Disk

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There are many fake capacity USB flash drives on the market that claim a particular capacity, but only deliver somewhat less than this (particularly the larger drives). This is sometimes referred to as fake ‘oversize capacity’. The counterfeit drives they have examined appear to have the stated capacity in Windows Properties and it is not until you test the drive with these software that you see that there is significantly less real space.

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There is also a similar problem of low quality drives (which may or may not also be counterfeit). These drives might have the capacity they state on the box, but be of such low quality that they corrupt files or lose data stored on them due to bad sectors. While many stores, such as Ebay and other online auctions, provide information on how to detect some of these fake USB flash drives, they generally rely on physical markings on the drive, such as incorrect serial numbers or typing mistakes on the packaging. Of course this only works for well known documented cases of counterfeit SSD drives, Flash Drive, SD Cards etc.

fake usb ssd Freeware To Detect Fake USB Flash Drives, SD Cards And SSD Disk

To avoid being cheated, ask the seller to run through their Flash Drive with one of these software and have the report emailed back to you. This will be a legal document in the event that he or she willingly sold you a fake product that doesn’t match the description. Here are some software that enables you to test the true capacity of your microSD Cards by SanDisk, Samsung, Lexar, Transcend, Kingston, Toshiba, Sony, Western Digital, ADATA and more.

1. Check Flash

Check Flash

Check Flash is a tool for testing and formatting flash-drives. It can be used to clean any evidence of activity on your flash drive by formatting it. With Check Flash you will be able to manage your flash drives by performing different maintenance tests on it. Except surface testing, allows check speed of reading and writing, edit partition info, save and restore full drive and partition images, save and restore MBR. Also can perform full drive or partition cleaning. Process speed is highest what a given device can provide, no faster full test can be found in the world.

2. RMPrepUSB’s “Quick Size Test”

RMPrepUSB Quick Size Test

RMPrepUSB’s “Quick Size Test” feature checks the drive capacity in just a few minutes by writing and reading to certain blocks. This test will DESTROY any files on your USB drive and is not a thorough test, if it passes then use H2TESTW for a thorough test (which can take many hours!)

3. H2testw

h2testw memory Freeware To Detect Fake USB Flash Drives, SD Cards And SSD Disk

H2testw 1.4 is the software victims of flash memory fraud use to test the real capacity of flash memory storage chips. Wise resellers use it to ensure inventory purchased is not for fakes before they list mp players, usb flash drives or memory cards on the internet to sell. H2testw 1.4 operates in English and German, it is a free software to download and use.

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How can you tell what the true capacity for a flash memory storage chip is, is it the operating systems report? The answer is NO ! This is the classic mistake people make. An operating system only retrieves information about flash memory storage from the usb controller chip and if it is a digitally altered one, it has been reprogrammed to lie! H2testw 1.4 catches the lie, it tells you the truth about the real capacity of the flash memory chip. It also spots grade C and D flash memory chips, ones that should have been destroyed.

4. FakeFlashTest (by RMPrepUSB)

FakeFlashTest RMPrepUSB

FakeFlashTest is a program to verify the real capacity of SD memory cards and flash drive media. The tool verifies the actual capacity of the disk by writing blocks of data with a size corresponding to the declared capacity of the media.

The application was created to identify false data storage media that appear more frequently on Internet auctions unscrupulous traders. Carriers having a capacity of eg. 64 GB in fact offer a record of up to 1 GB of data. Displaying inaccurate information regarding the system disk capacity is the result of a suitable memory mapping. FakeFlashTest during the review process overwrites all data carriers. Before starting the process to verify the capacity of the selected drive or SD card, please make a copy of all stored files.

5. ChipGenius

chip genuine Freeware To Detect Fake USB Flash Drives, SD Cards And SSD Disk

If you have a USB Flash drive, try using ChipGenius as a first test and a very quick ‘test’. Often this will reveal the true size of the memory chips(s) fitted by the manufacturer.

6. USB Flash Drive Tester

USB Flash Drive Tester

Flash card/drive tester allows testing of any removable media including SD, MMC, CF, USB flash pen drives for bad or unstable sectors. Especially useful for testing for fake sizes often seen on low quality USB pen drives.

7. USB Memory Stick Tester

USB Memory Stick Tester

USB Memory Stick Tester is a small application designed to help testing removable storage media (such as USB memory sticks) for defects.

8. BurnInTest

disk test

Using BurnInTest you can actually test whether your USB flash drive has the amount of storage it claims or not, and test the ability of the drive to store and retrieve data without corruption. BurnInTest can be used to write, read and verify large amounts of data to and from the drive, detecting oversize capacity and poor quality drives in the process. This process assumes you already have a licensed version of the BurnInTest software. (You can use the eval edition of BurnInTest, but the evaluation edition is limited to 15min runs which might not be not run long enough to test large drives)

9. F3 Fight Flash Fraud

F3 Fight Flash Fraud

f3 is a simple tool that tests flashcards capacity and performance to see if they live up to claimed specifications. f3probe is the fastest way to identify fake drives and their real sizes. f3fix enables users to use the real capacity of fake drives without losing data. f3brew helps developers to infer how fake drives work. f3probe, f3fix, and f3brew currently run only on Linux.

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10. CapacityTester


This tool can test a USB drive or memory card to find out if it’s a fake. For example, a fake might be sold as “64 GB USB thumb drive” but it would only have a real capacity of 4 GB, everything beyond this limit will be lost. Write requests beyond that limit might be ignored without error, so a user would not be notified about the data loss. This tool performs a simple test to determine if the full capacity is usable or not. All it does is fill the volume with test data and verify if the data on the volume is correct. The volume must be completely empty for the test to provide reliable results. For Linux only.

11. MediaTester

mediatester fake usb drive

MediaTester can test any media (SD, microSD, thumb, etc) and verify it stores the expected number of bytes. The testing method is similar to h2testw but MediaTester can detect fake or defective media much faster by performing quick reads as data is written. If you buy any storage media, you should use MediaTester to verify it or risk losing your data.

Fake media sales have reached epidemic proportions. Fake media is being falsely labeled with popular brand names including SanDisk, Samsung, Sony, Kingston, and others. Not only are these counterfeit but they often contain less storage than the cards report to the computer. A 128GB SD card may actually contain only 8GB or 4GB of actual space. After filling up all of the real space, the card will respond as if it is storing the data but it is actually throwing it away. The files will look like they exist but they are actually full of null bytes or completely corrupted. If you try to read the data you will find that it is ALL GONE.

microSD Card Scam – Fake Capacities

Scam SD cards are common. These fake capacities with firmware, explained in this video, will appear as “32GB” (or even up to “1TB”), but might only support 4GB in reality. It’s often obvious that it’s a scam, like with mismatched prices or untrusted sellers, but these fake SD cards have begun infiltrating the likes of large online retailers and physical retailers.

Illegitimate capacities and/or write class. Remember, if the price is too good, the product is probably bunk.


  1. Gravatar
    Bharath Ram [ Reply ]

    Fantastic list!

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      Please recheck links, some dont work.

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    None of this software will test sd card plugged into phone and connected to PC via USB

    • Gravatar
      Bartosz77 [ Reply ]

      Get yourself an adapter, put the card into a laptop or PC and the problem is solved!

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      Alan Grant [ Reply ]

      Use SD Insight. For Android.

      • Gravatar
        Titane [ Reply ]

        SD Insight is not available from Android 7 onward because Google has blocked its API. Do we have any alternative?

        • Gravatar
          Brian Ciesicki [ Reply ]

          Got any file testers for Android?

          Also I want something for Mac that doesn’t rely on internet. My fastest non-phone net speed is 5Mb in and out.

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      Energy Level [ Reply ]

      On Android, there’s another app (new one): “True SD Capacity/Speed Test” – unleashed my new fake cheap Chinese TF card SanDisk 256GB Extreme > Writing process was a bit slow (1st thing I found bad about this fake card), then after verifying approx 30GB from the card, errors started to appear from the read/verification process (75% of each file after the first 30Gigs was corrupted!!)
      App is brilliant! Card is ‘bunk!’

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      This is why you use external card readers

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    Daniel Johnson [ Reply ]

    If these dodgy cards are made by getting a card to pretend to be bigger than it is, then is it possible to get it to stop pretending, and use it at the correct size?

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      Ngan Tengyuen [ Reply ]

      I guess it is possible but I have no idea how to modify a firmware.

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        partition it.

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          John Drake [ Reply ]

          It depends. I bought a “1TB” SD Card from a highly rated eBay vendor. I knew for $20+free shipping it was bogus. Popped the card into my Linux computer, and sure enough is showed up at around 1TB space, in MB. I ran h2testw on the card (yes found Linux version), and after 16GB of data was written, you could no longer write to the card. Re-formatting, re-partitioning, deleting existing files: all failed. The card was totally borked. I complained to the seller, and he refunded my money. Didn’t even want the card back. I told the seller his inventory of cards was all junk. He said he never heard of this scam before. He also said he was a “front man” for the supplier. Whatever. I didn’t pursue this with eBay, but I should have, as many unsuspecting people will loose their pictures/music/etc after writing 16GB to the card. This was a couple of years ago. Now, any high capacity SSD device I test by fully writing/reading to the device before trusting it, even the SanDisk 128GB twin pack I just bought from Costco.

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            Ira LJ

            How did the “SanDisk 128GB twin pack [you] just bought from Costco.” Test? Was it a fake or OK?

  4. Gravatar

    This scam has been going on so long i am amazed that the manufactures haven’t provided an official testing utility a long time ago – unless stopping this illegal trade wasn’t in their best interest, e.g. they get to sell off loads of small, slow, possibly even potentially faulty memory much of which will end up in the bin relatively soon.

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      Ngan Tengyuen [ Reply ]

      “manufactures haven’t provided an official testing utility” And how are the manufactures suppose to provide a testing utility when the product itself is fake and not manufactured by them? If the product is fake, it is not the manufacturer’s fault, they do have teams that goes around and check for fake products but they can’t be everywhere.

      To avoid fake products, always buy from reputable retailers.

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        Sean P [ Reply ]

        The crazy thing with this scam is the fakes are sold by reputable retailers. I don’t know if they’re from return fraud or what, but you can get fakes direct from major retailers.

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        Wa Buzzoo [ Reply ]

        It may not be the manufacturers fault, but why not provide a utility to verify if a product is legitimate? They could provide a utility that users could download from the manufactures website for testing suspect cards. It would be pretty easy for a manufacturer to make a utility that would identify if a product was something they produced, scanning the firmware to see if it’s legitimate, etc. Samsung could make a utility to identify legitimate Samsung cards, Kingston could make a utility to identify Kingston cards, etc. Any one of them could make a utility to write to a card and do a capacity test. They make the cards, they should be the best at writing software to check them. I don’t understand why we have to resort to third party software for detecting this problem.

        • Gravatar
          Ngan Tengyuen [ Reply ]

          They must have their own reasons, maybe this problem is not so widespread to warrant any attention. They probably know what they are doing, if you purchase your SD Card or Thumb drive from a reputable retailer, you have nothing to worry, and if it is fake, the manufacturer will take action and you can sue the retailer for money due to data loss. These USB flash storage devices are pretty cheap now, no reason to save USD5 just to get it from ebay. Go to a big retailer and it will be ok.

  5. Gravatar
    Osman Mat Safri [ Reply ]

    Can we use the flash drive test for micro SD test

  6. Gravatar
    Marcus Erectus [ Reply ]

    Got anything that will permanently change the true ‘total size’ information stored on the control chip that controls the flash drive to the correct usable size? My flash drive claimed to be 128GB, FAKEFLASHTEST software found it should be changed to 28.4589667 GB. So I reformatted using RMPrepUSB. Still if I retest using h2testw it will revert back to 128GB but only 128 useable. I want to permanently change the true size to 128GB, cause many years from now I might reformat the flash drive and it will return to the bogus 128gb because of the bogus data on the chip controller on the flash drive. Anything?

  7. Gravatar

    what kind of article puts as reliable a tool (ChipGenious) that isn´t updated since 2009, and link is broken, maybe thanks God!

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    dkrahmer [ Reply ]

    I wrote MediaTester a couple years ago to test for fake media. I just released an update today (1/8/2020) with full C# source if anyone is interested in yet another option. :)

    • Gravatar
      Ira LJ [ Reply ]

      I am interested in your MediaTester for checking the true capacity of drives I have purchased via the web. How can I get it?

  9. Gravatar

    How to make fake flash storage

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    fivish [ Reply ]

    Amazon were selling Western Digital HDDs as brand new.
    They were old and had multiple bad sectors.
    The label on the HDD still had the year of manufature and the SMART data told the rest of the story. They must have been taken out of laptops sent back for repair.
    Returned it for one they said would be brand new. It was the same!!! Got a refund.
    Bought one direct from WD and it was proper new.

  11. Gravatar
    @45Steven [ Reply ]

    I thought this would not test my 2TB no brand name USB flash drive however I compared it with the real thing that shows so much and the no brand name is near nothing and stores so little now I see why.

  12. Gravatar
    Florian [ Reply ]

    I have bought an portable SSD from Aliexpress. The speed is awful but it passed the 2TB test succesfully with h2test. Do you think the chinese have found an way to cheat the test process?

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      Observer2022 [ Reply ]

      Nope. Failed chips can be “just too slow for product owners current market” but functional at lower speeds. Sounds like what you got.

      Its part of silicon physics that many chips from the same manufacturing batch actual function at different speeds. Chip QC not only looks for parts that totally fail – but they also sort chips but how fast they can work before becoming unstable.

      Its well known that chip factories offering low cost manufacturing to main brands, often salvage and sell second or third tier products with lower speed or reliability. This can be part of the official contract. Equally likely is people just “looking the other way” or dumpster diving where disposal of failed chips is lax. Half of China earns its living this way. And its does not always start as a scheme to defraud. But given a chain of people making and distributing a “less than ideal” product, someone along the way will see a way to earn a dishonest buck.

      Occasionally ORIGINAL manufacturers will also sell a second lower range of speed as a discount line of “seconds” (second quality) for various low end industrial or academic purposes.

      For official seconds etc, there used to be different brands or other marking for this. But I am not sure that is still done even officially. Making the issue of fakes even more confusing.

    • Gravatar
      Observer2022 [ Reply ]

      Test for reliability and then use it for archival/backup storage.

      Aliexpress is probably using chip “seconds” rejected as too slow from a factory making chips for a bigger Product Brand. Or perhaps they bought a batch of now obsolete chips. However, I have seen the brand often enough to think they obtained the chips “legally” instead of dumpster diving or theft.

      They possibly compounded the slow chip issue (slower than anything main brand would currently use) with a poor performing PCB design and poorly designed SSD firmware. They may have used too large an array of smaller and slower obsolete chips. (Storage chip arrays work slower as they grow in size.) They may even have a loose QC process that does not catch all products that are too slow, even for Aliexpress intentions.

      All these things are more likely for new and second tier manufacturing on a shoestring budget (not having many or any experienced, top notch engineers is a bad handicap).

      • Gravatar
        Observer2022 [ Reply ]

        One caveat. There are certain brand names from China that really do not seem like they are owned by any one company or association. That is all the scammers seem to start jumping on the same “unprotected” brand name in order to seem like their product is produced by a much larger company. Some of that seems like it might be organized by people associated (officially part of it or not) with a certain online marketing company.

        Anyways look at bunch of SSD photos from any given Chinese brand with which you are not familiar…with an eye toward consistent quality appearance. Scammer brands tend to be dominated by lots of unexpected variations in labels and other appearance. Occasionally there are some really bad looking fakes (torn or smeared labels, even wiring poking out).

        Even for legitimate brands it helps to know what their products should look like – as Chinese scammers are not shy about faking any real brands. Nor does it seem most Chinese marketers and exporters are super careful about rejecting even easily detected fakes.

  13. Gravatar
    Observer2022 [ Reply ]

    Why the manufacturers are not more behind detection software? Two easy answers.

    First its great marketing (far more reliable than offbrand X, Y and Z!!!) and allows real brands to hike the MSRP of products. Fakes decrease the price lowering effects of head to head competition with other real products by creating a vast fog of products too hard to track. Plus any poor or lemon products released by real companies (nobody is perfect) can be discounted as fakes.

    Second because the fake storage chips are a side business of the Chinese factories that make most of the actual current quality storage devices. Basically Western capitalists have very low manufacturing costs for current products because they do NOT ask questions about what happens to chips that are obsolete or fail QC tests. Plus no threat of western regulators or investigative press. Excepting for impact on foreign trade politics, junk products are essentially a legal business within Asia.

  14. Gravatar
    Rodney [ Reply ]

    Perhaps you missed Sean P’s reply to you. This is a widespread problem. Although it primarily affects eBay/other unofficial retailer channels, big retailers are not spared. As Sean said, it’s probably due to return fraud- buy an authentic card from an official retailer, return a fake card that looks the same and is in sealed pack, get money back, keep authentic card. Retailer resells returned sealed fake card to someone else.
    I wouldn’t be so quick to assume the manufacturers know what they’re doing when they’re being duped by returns fraud. They should provide a utility that checks the authenticity of their cards.

  15. Gravatar

    My “2TB” is only 60 GB thanks to MediaTester- You will need to delete fake partition and create new with real capacity

  16. Gravatar
    Russell [ Reply ]

    when was this feed/form/comment section last updated?

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