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

I ordered a couple of cheap 256gb SD cards from Amazon, then began regretting my decision to go cheap. I downloaded this app to test them for peace of mind, and found they corrupted 25% of data written to them. I've returned the cards, I have no regrets about buying this app for a dollar

If you've not got a computer or laptop or just don't have one handy this app is perfect for testing micro SD cards to see that their legit. This is basically like the PC's H2testw tool, but only for Android

Works great! Make sure you don't lose data by identifying inferior and counterfeit cards.

What’s new

Full android 16 support.