Birthday Rank

An interactive visualization showing the relative frequency of birthdays in the United States. Built with SvelteKit and D3.

Live site: birthdayrank.com

Features

• Interactive heatmap showing birth frequency by calendar day
• Select your birthday to see how it ranks (1st to 366th)
• Conversational descriptions of rarity (quite common to quite rare)
• Downloadable share images for social media
• Responsive design with light/dark mode support
• Shareable URLs via hash (e.g., #9-9 for September 9th)

Data source

Birth data comes from FiveThirtyEight, combining:

• CDC National Center for Health Statistics (1994-2003)
• Social Security Administration (2000-2014)

The data pipeline uses CDC data for 1994-1999 and SSA data for 2000-2014 to calculate daily averages.

Development

npm install
npm run dev

Refreshing the data

The data processing is handled by Python scripts in the data/ directory:

# Install Python dependencies
pip install -r requirements.txt

# Fetch raw data from FiveThirtyEight
python data/fetch_data.py

# Process and generate birthdays.json
python data/process_data.py

This will update src/lib/data/birthdays.json with the latest processed data.

Building for production

npm run build
npm run preview

Deployment

This project is configured for static hosting on Vercel.

The static adapter outputs to the build/ directory.