| sex | No | girl, boy or any (default any: girls and boys listed separately), e.g. girl. | |
| sort | No | Order: popular (most 2025 births), rising (biggest growth), alphabetical, rarest (fewest 2025 births). Default popular, or rising with rising_years. | |
| limit | No | How many names to return, 1-60, e.g. 30 (default). | |
| era_to | No | Era end year, e.g. 1959. | |
| unisex | No | true = names where girls are 40-60% of 2016-2025 US births (at least 100 births in that period). Example: true. | |
| vintage | No | true = vintage names: top 300 in some year 1910-1930 and outside the 2025 top 1,000. Example: true. | |
| contains | No | Name contains these letters anywhere, e.g. "rose". | |
| era_from | No | Era start year for 'popular back then', e.g. 1950. | |
| rank_max | No | Highest 2025 rank number to include, e.g. 1000. | |
| rank_min | No | Lowest 2025 rank number to include, e.g. 200. | |
| ends_with | No | Name ends with these letters, e.g. "lyn". | |
| max_length | No | Maximum letters, e.g. 6. | |
| min_length | No | Minimum letters, e.g. 3. | |
| popularity | No | 2025 rank band: top_100 (1-100), common (101-200), familiar (201-1000, familiar but not common), uncommon (1001-5000), rare (5001 or lower). Example: familiar. | |
| starts_with | No | Name begins with these letters, case-insensitive, e.g. "a" or "el". | |
| era_max_rank | No | Rank a name must have reached in some era year, e.g. 100. Default 300. | |
| rising_years | No | Only names with more births in 2025 than N years earlier, sorted by growth, e.g. 10 (compares 2015 to 2025). | |
| max_syllables | No | Maximum syllables (approximate), e.g. 2. | |
| min_syllables | No | Minimum syllables (approximate), e.g. 2. | |
| min_births_2025 | No | Minimum US births in 2025, e.g. 100. Default 50 when rising_years is set, else 0. | |