How to Decode a QR Code by Hand

[GabrielTobing]

When you're that one guy that is watching this for fun, and not for any work related reasons.

[RonNV]

I don't ever comment on videos. But I have to thank you for this. This was awesome. I can imagine the time it took to create all of these graphics, and want to thank you for your efforts. This is exactly the kind of thing I love to find online.

[AgentM]

Someone make a vacation QR puzzle book.
Would be terribly hard but fun. (For the real nerds)

[randertonyo]

This guy is AMAZING! He takes something VERY complex, and makes it understandable. Thank you so much.

[MM-tsjy]

Dude I've been looking everywhere on youtube a video explaining how QR codes work, and they all say "How a QR code WORKS" but all they do is explain what they are and how to download an app to install it (aka bullshit title). Now that I've watched your video I can see why there are no videos explaining this shit, it's so complicated. Thank you so much for uploading this, I can see it's hard even for you to explain it. Also I'm subscribing.

[xtrme]

I'm not sure why you stopped putting up videos, but this here is an absolute work of art! Thank you so much for giving us such a thorough video! Well done and hope to see more from you in the future.

[jeffkiku]

I just saw a short program about the Japanese guy who developed the QR code but they didn't say anything about how it worked. Your use of an Excel spreadsheet was pure genius and actually made it understandable. Now I want to read the Wikipedia article to learn more details. Thanks for producing this video. It was both entertaining and informative.

[andrewwood]

still such an awesome video even in 2024 thank u bro

[mufmager]

This is probably something that a human can not even fully learn, no matter how much practice he takes on it.

[FloIancu]

Thank you so much for this tutorial. I'd been searching for this info the whole day until I got to you and not only did you make black dots understandable, but I was laughing the entire time. Keep them coming! :)

[anshumansrivastava]

I know I am never gonna do this but it was nice to see someone explained it very well which was mystery for me for few years

[queeniefcharles]

hey. I woke up with the obsessive idea to reverse engineer/decode a QR code. I couldn't thank you more for making this video, such a great amount of work, and purely explained. thank you very much

[robinmarsh]

This was very enjoyable, I have no real grasp on data, programming or anything other than breaking data for glitch art, but this was really fun.

[Its_Pritam_]

I just implemented a barcode API in an app! Then I was curious about how exactly it works! And here I'm right now!

[bobanderson]

Nice video. However it is much simpler and faster to find the characters in the ASCII table if you convert the block pattern direct to the octal values (i.e. no adding up is needed!). For example, your lower case "s" at 18m48s is the bit pattern 01_110_011 where I have separated the pattern into the 2 and 2/3 octal characters with underscores. With a few minutes practice you can just read that off as the octal number 163. Now look over to your ASCII table and there you see the octal number 163 next to the lower case "s". No sums required! There are only 7 octal patterns to remember and you can then translate any number of bits to octal or just do the mental adding up of the 4 plus 2 plus 1 bit values for each character in your head.

[joebloggs]

A bit (or 2 or 3 ...) complex for a tech illiterate like me, but I do know a bit about QR codes or know what one looks like and often wondered how they work. This well explained video on a complex technical topic gave me the sort of general idea of how they encode their information. That is all I wanted as a curious lay person. Thank you.

[danwhaley_]

This is what true content looks like. THANK YOU. Perfectly done.

[philteng]

This is the best video explaining qr code I have seen so far. Thank you.

[davemound]

Who knew Kermit the Frog knew about QR codes!! ... ;) Thanks for the info, great vid.

[peridoritothemighty]

This is phenomenally well explained, even if it is more complicated than it looks