True SD Card Capacity Test +

Alan Robinson

About this app

This "short" endurance test confirms if you SD card is valid and reliable or if it's a counterfeit that has way less storage space than advertised. It fills your card with carefully designed files that the app can then verify to ensure that what's written to your flash card can be read back reliability. It also measures read & write speed at the same time, because, why not?

It's not the most pretty app because the focus has been instead on real-world testing and good algorithms. It is, however, easy enough to use. The only way to know your card is good is to fill it to the advertised capacity. Typically this takes less than an hour but can be longer if the card is particularly slow or enormous. You can leave it running overnight. Piece of mind is worth the wait and there are no shortcuts to it!

You can also test your phone's internal storage. With USB-OTG some phones will let you test thumb drives too, but many phones don't follow the spec properly and don't give access to the OTG drives.

Note: interface is in English only.

Ratings and reviews

Great app. I checked my 1tb Sandisk micro. I let it fill it up to full then verified data. No issues were. It took 12 to 15 hrs to complete which is to be expected on such a large micro sd storage card. I just used in a backup phone. Didn't overheat my phone in the process. I restart my phone before using and reformated and set test to 100%. It pass no errors no where not on none of the files. So I feel comfortable feeling it up my data. Great app Alan. I have 235gb and 128gb I'm going to test.

Absolutely awesome excellent app, takes a while with a 128 gig card, but definitely worth the wait and piece of mind. It's definitely worth paying for the full version as I personally think the developer deserves it. Unlike many many other apps on the play store, this has absolutely no pesky advertising, so it's a win win. I've tried loads of different applications but quickly deleted due to not being functional due to ads and not being able to test properly. This app is perfect. Well done.

Definitely worth the price. Simple app that does exactly what it promises, without hijacking your device and serving a loud, 30 second TikTok ad that's intentionally tricky to X out of. If you're going to format your micro SD card as adoptable storage, or even if you're not, this app will tell you what kind of shape it's in.

What's new

Now with android 14 support!