Custom Mailbox Betacoins

August 20, 2014

Yesterday, Mailbox released their beta Mac app. One cute thing they did, was that instead of a beta link or code, they distributed cute little animated gif coins which you could then drop into a “tin can” in the app to gain access.

A betacoin

I was intrigued by the concept, so I got some used betacoins from my friends and did a little digging to figure out how they were doing it.

My plan was to diff the coins and see what was changed from coin to coin, but I didn’t even need to do that. A quick inspect with gifsicle revealed an obvious token in the gif comments extension block.

[email protected]:~/Desktop/betacoins ✪ gifsicle -I coin113121.gif '#0'
* coin113121.gif 122 images
  logical screen 173x130
  global color table [64]
  background 44
  loop forever
  + image #0 173x130 transparent 45
    comment "F1699622-5500-4F31-B643-798427D0DBFA"
    disposal asis delay 0.03s
[email protected]:~/Desktop/betacoins ✪ 

From there I checked a couple other coins to see if they had differing comments, and sure enough they did.

So now the question became, could I add the comment from a valid betacoin to another gif and have it still work?

I grabbed a lovely gif of a barfing unicorn off the web, and set to work.

[email protected]:~/Desktop/betacoins ✪ gifsicle unicorns_puke_rainbows_by_chronicle_vindictive-d56nvl0.gif  --no-comments -c '"F1699622-5500-4F31-B643-798427D0DBFA"' '#0' '#1-' > unicoin.gif
[email protected]:~/Desktop/betacoins ✪ gifsicle -I unicoin.gif '#0'
* unicoin-a.gif 9 images
  logical screen 660x850
  global color table [256]
  background 0
  loop forever
  + image #0 660x850
    comment "F1699622-5500-4F31-B643-798427D0DBFA"
    delay 0.92s
[email protected]:~/Desktop/betacoins ✪ 

I then downloaded the beta, crossed my fingers, and dragged the unicoin into the tin can. I was rewarded with a tinkle of a coin dropping in, and access to the beta.

This is a valid betacoin.
This is a valid betacoin.

Turns out, Mailbox could care less what else is in your gif. Just so long as you have a comment with a valid token, it’ll use that gif and animate it prettily.

As an aside, the coin gif has a staggering 122 frames. 122. Sparkles are expensive, yo.

Edit (2014-08-20)

I created a service for changing up your Mailbox betacoins, called Unicoin. You’re welcome.

Second Edit (2014-08-20)


Categories: Geek
Tags: ,


  1. So cool. Thanks for pulling it apart.

  2. Megan Casey says:

    Give it all to Hobbs.

  3. Any chance you can post the Unicoin site source? Curious as to how you made that tool. Awesome work!

  4. Karthik K says:

    Wow. Such an amazing post Mr. Hobbs. Brilliant work. :)

  5. John Hobbs says:

    @Charlie – I’ll try to get it cleaned up and posted to github tomorrow. It’s mostly just shelling out to gifsicle.

    @Karthik – Thanks!

  6. Juliette says:

    That’s so…wait for it….vomixtrodinary!!
    Glad you did that!
    And you rocks for that one: P.S. I promise not to steal your betacoins.


  7. Yao' says:

    Actually, the unicoin trick doesn’t work for now. Is there an update by Mailbox team ?

    Thanks for the try ;)

  8. John Hobbs says:

    @Yao’ – Weird, it’s worked several times for me. Maybe they pushed out an update today. Does it give you an error message?

  9. watch84 says:

    Super awesome. The second I went through this experience I dove into a search as to how it’s done. No results until today. Thank you!

  10. ymipaul says:

    I tried it just now and it did not work… any other options?

  11. Jesse says:

    It just does the graphic where the tin spits out the coin. No real message.

    Great post when it worked :(

  12. John Hobbs says:

    @Jesse and @ymipaul – Bummer! I’ve got no idea why it works sometimes and doesn’t other times. Maybe the token is already used?

    Either way, if you need a Mailbox betacoin, I can send you one!

  13. Kimball says:

    Um yeah…if you have a betacoin could you send one my way? :)

  14. Victor says:

    Thats soo cool thank you for sharing, any chance to get a betacoin?


  15. […] the way, this cool dude made this little website where you can change the Gif on your Betacoin before using it. Not sure […]

  16. John Hobbs says:

    And just like that, I’m all out of betacoins.

  17. […] Mailbox (Mac) A few days ago, Mailbox released their beta Mac app and so far it’s awesome. If you’re willing to try it, just write me a short message (I have three invitations to share). To use Mailbox you’ll need a so called “Betacoin” and in this article you’ll learn, how this idea works. […]

  18. Eoin says:

    Really struggling to find a bet coin online anywhere. Would be most grateful if you could pass one on :)

  19. Luca says:

    Hi, can you send me a betacoin. Appreciate it. Cheers

  20. Kiki says:

    Hmm I have a beta code but not a beta coin. Any idea what I do with that? :) Help appreciated.

  21. Marcio says:

    Hi, appreciate if you have new betacoins. Really looking forward to use Mailbox on my laptop.

  22. AM says:

    if someone could send me a beta coin I’d highly appreciate it. I’ve been a longtime user of the iPhone app and can’t wait to get my hands on the desktop version!

  23. jehn says:

    ha! I love shit like this! Great job :)

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