The numbers

The Social Security Administration publishes one file for every year of birth since 1880. Each file lists every name given to five or more babies of one sex in that year, with the count. Names given to fewer than five are not published, so every figure on this site is a floor. A name that “appeared in only one year” appeared for five or more babies in only one year.

We rank names by count within sex within year, in the order the file gives them. Shares are per million births of that sex in that year, so that a name's line can be compared across a century in which the number of babies changed a great deal. “Peak” means the year of highest share, not highest count.

The counts come from applications for Social Security cards, not from birth certificates. Before 1937, when a number became something most people got as an infant, many never applied until adulthood, so the early decades count whoever later filed, not everyone who was born.

The agency normalises names before counting. Case and spacing are merged, so Julie Anne and Julieanne are one entry, while Caitlin and Kaitlyn stay two. A name needs at least two letters to qualify. Where two names have the same count, the earlier letter of the alphabet takes the better rank, so adjacent ranks do not always mean different counts.

Our copy of the file was taken on September 13, 2026 from a public mirror, because the agency's site does not answer requests from our network. It will be checked against the original when the 2025 file is released in May. The data is in the public domain.

Agent figures come from the registry, which is a file too, and from filename counts in public GitHub repositories, which are upper bounds and are labelled as seeds wherever they appear.

Pet figures come from two municipal licence datasets: the NYC Dog Licensing Dataset, aggregated by name, and the Seattle Pet Licenses dataset, aggregated by species and name. A count is a licence record, not an animal; a dog renewed every year appears once per licence period. Placeholder entries such as “Unknown” and “Name not provided” were removed, about five percent of New York's rows, and names were title-cased to match the human file. Nothing else was cleaned, so the kennel still contains jokes.

Both cities publish the data without restriction: Seattle marks it public domain, and New York's portal states there are no restrictions on the use of Open Data. Details, dates, and the exact queries are in data/pets/README.md.