Birthday Traffic turns official birth records into a personal birthday reveal. Pick any date to see how rare it is across 85.7M U.S. births, explore patterns from 7 countries, then turn the result into a birthday card you can customize and send as a link. No account or install. Built with GPT-6 Astra to reconcile messy public datasets and turn the research into a working, source-linked product.
What became possible in your product with Astra that was not practical before?
Maker
Birthday Traffic started with “Why are there so many September birthdays?”
Astra made it practical to take that rabbit hole way further than I expected: pulling apart long government reports, reconciling incompatible datasets across countries, checking overlapping source years so I wasn’t double-counting births, catching weird edge cases around ties, leap day + partial-year data, and generating a legit realistic spinning disco ball and jazz music for the experience!
That’s how it went from a joke at a coffee shop to a source-linked product built on 85.7M U.S. births, with research, country comparisons, 366 shareable birthday pages, and now an entire birthday-card maker.
And people actually used it: 36,000+ site visits in the first few days, including a huge one-day organic spike and Google search traffic starting to show up almost immediately.
Report
Maker
📌
hi, i'm adrianna!
birthday traffic started because of a coffee shop conversation about why there seem to be sooo many september birthdays.
then i started actually researching it and found out that september 9 is the most common birthday in the U.S. data i was looking at.
and i was like… wait. hold up. so instead i started asking: how rare is your birthday, actually?
that turned into birthday traffic.
i used GPT-6 Astra to help me go way further down the rabbit hole than i expected, pulling apart government datasets and reports, reconciling sources, checking overlaps so i wasn’t double-counting births, dealing with ties + leap day properly, and interrogating every fun-sounding claim before putting it on the site. the main checker now uses 85.7 million U.S. births, with more official data from other countries behind the explore + research pages.
i posted the first version on X this week and one day later over 26,000 people showed up.
so i kept going.
i added a spinning disco ball because obviously. jazz happy birthday music because also obviously. better sharing. personal birthday cards. and now an entire birthday card maker where you can write a message, change the design, add stickers, send someone a link, and they open an actual little envelope + card on their phone.
is it an unreasonable amount of birthday infrastructure? maybe. do i look forward to making it even more unreasonable? will i expand the birthday-tech universe? absolutely.
the funniest part is that this was supposed to be a tiny conception calculator.
if you try it, tell me your birthday + whether the result was what you expected.
also pls try the card maker! it’s brand new, probably still has a janky moment or weird edge case somewhere, and i want your feedback / feature requests / questions / bugs.
complaints about your basic, boring birthday should still be directed to your parents lol