Hey r/SideProject,

I launched https://sendb.day three weeks ago. Here’s what it does:

You fill in a name, birthdate, and an optional photo — it generates a shareable link like
sendb.day/redditturns21.

The person opens it and gets a personalized birthday page. No account needed, no app to install. The whole thing is one HTML file.

https://reddit.com/link/1tbycsm/video/e8tvutqcfw0h1/player

What I’m most happy with

The page automatically picks a visual theme based on birth year.

• Born in 1962? → Boomer theme
• Born in 1995? → Millennial aesthetic
• Born in 2015? → Gen Z

It’s dumb fun, makes the eyes and ears bleed, but people seem to enjoy it.

Technical choices I’d love feedback on

• Everything is URL‑encoded — no database needed for the birthday page itself. The URL is the page.
• Single HTML file, no framework, no build step. ~6,000 lines of vanilla JS/CSS. Probably not how you’d do it at work, but for a side project it’s been surprisingly maintainable.
• Optional short URLs via Firebase when the full URL gets unwieldy.

What I’d love feedback on

1. The landing page — is it immediately clear what you get?
2. Does the “themed by generation” concept land for non‑German users? (The site auto‑detects language, but it started as a DE‑focused project.)
3. Anything that made you drop off before creating a link?

Honest state

~240 real pageviews in 3 weeks
5 people have created and shared birthday pages

Small, but real.
I’m trying to figure out what to improve before putting more time into it.

Link: https://sendb.day/reddit