Households without a car make up 2.9% in By, less than in 99% of compared French towns
In By, 6.1% of homes are second homes, beside 2.1% in the typical compared French town. 6.6% of residents are 15 to 24, or about one in 15. Few places have as many households headed by a retired person: 50% here, more than in 97% of compared French towns. There were 36 households here at the 2023 Census, home to 79 residents.
Throughout this page, the Doubs median and the France median are the median of compared communes (those with an overall grade), each figure its own median. Source: INSEE, census 2023.
What stands out about the people of By
A town of families
33% of households are couples with children and 0% single parents with children; 22% of residents are under 15. Households ↓
Many graduates
52% of residents 15 and over who have left education hold a diploma above the bac, 20% a master’s or more (bac+5). Qualifications ↓
Empty homes
The census found 7 homes empty (14%): for sale, to let, awaiting work or simply unused. Homes & cars ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
A growing town: +14% since 2012, faster than 81% of compared French towns
Residents at INSEE’s last three censuses, each recast in the 2026 commune boundaries. France has no yearly estimate by commune between censuses.
2012 to 2023
2017 to 2023
The change was +13% from 2012 to 2017 and +1% from 2017 to 2023.
By is younger than 73% of compared French towns: a median age of 41
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ By 41. The median compared French town: 44.
Put another way, about one in five: 21% of residents are 65 or over.
Women and men · all residents
46% women, 54% men
About 117 men for every 100 women. Median share of women: Doubs 51.3%, France 51.8%.
A higher share of couples with children than 88% of compared French towns, at 33%
A household is everyone who shares a main home (résidence principale). Household types come from INSEE’s fuller sample of a quarter of census forms.
Against the Doubs median and the France median
Living alone · share
35% of households are one person living alone in the typical compared French town, against 33% in By. Single-parent households are rarer here than in 99% of compared French towns. For comparison, 25% of households are couples with children in the typical compared French town. The average household has 2.2 people.
A higher share of empty homes than 94% of compared French towns, at 14%
Every home the census counted: main residences, second homes and occasional dwellings (INSEE counts them together), and empty homes. Owning and renting are on Cost of living.
All homes · share of homes
Type of home
Cars per household · share of households
Households in social housing are rarer here than in 99% of compared French towns. Empty homes: 6.7% in the typical compared French town, for comparison. 6.8% of homes are flats.
The largest group of households: retired (50%)
Households by the socio-professional group (PCS) of their reference person, INSEE’s own categories. Jobs and commuting are on the Work & commute page.
Households by reference person’s group · share of households
Households headed by a manager or professional are rarer here than in 99% of compared French towns.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Foreign nationals: 1.3%, a lower share than 89% of compared French towns
INSEE publishes two measures, which overlap but aren’t the same. Neither is the UK’s “born abroad”.
Share of residents · census 2023
Immigrant (immigré)
Born abroad, not French at birth. Someone stays an immigrant after becoming French. A French citizen born abroad (for example in Algeria before 1962) is not one.
Foreign national (étranger)
Not a French citizen today, wherever born. A child born in France to foreign parents can be a foreign national without being an immigrant.
3.9% of residents are immigrants; in the typical compared French town the figure is 6.5%. Immigrants make up a share lower than in 74% of compared French towns; the median compared commune in Doubs has 8.5%. Typically, 4.3% of residents are foreign nationals in the typical compared French town.
INSEE publishes no country of birth or ethnicity by commune in these tables, and the census doesn’t ask about religion.
32% of residents 15 and over are married, fewer than in 96% of compared French towns
Residents 15 and over by how they live: the census asks both the legal status and whether people live as a couple.
Residents 15 and over · share
In the typical compared French town, the share of single residents is 25%; By has 31%. The usual figure: 43% of residents 15 and over are married in the typical compared French town.
By ranks below 97% of compared French towns on adults with no qualification: 8.9%
Highest diploma of residents 15 and over who have left education, in French terms: the levels don’t map one-to-one to UK or U.S. ones.
Highest diploma · 15 and over, out of education
With graduates of higher education at 52%, By is ahead of 94% of compared French towns on that count. Elsewhere, 19% of adults out of school have no qualification in the typical compared French town.
4th lowest median age among 41 French towns of 79 to 2,582
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
Villejust is the youngest (37.2); Prayssac the oldest (62.3).
A younger town than 5 of the 6 around it: By
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
Health, work, housing and schools
What this data can and can’t tell you
- Census 2023. INSEE’s census is a rolling survey: a fifth of small communes each year, 8% of homes in large ones each year. “2023” pools the surveys of 2021 to 2025, so the figures describe the town around 2023, not on one day.
- Medians of compared communes. The comparisons are the median of the département’s compared communes and of France’s (those with an overall grade), each figure its own median: not the total for the département or for France, which large cities pull towards their own figures.
- Immigrants and foreign nationals. INSEE’s two measures: an immigrant was born abroad without French nationality; a foreign national isn’t French today. Neither is a count of people born abroad, which INSEE doesn’t publish by commune.
- Second homes. Homes used for holidays or weekends, with occasional dwellings (kept for work, for example), which INSEE counts together. Their owners are counted where they live, not here.
- Standard of living. INSEE’s Filosofi: disposable income per consumption unit, from tax and benefit files, 2023. The poverty rate is the share of residents below 60% of France’s median. Not published for the smallest communes.
- What France doesn’t ask. The French census asks nothing about ethnicity, religion, language or health, so this page has no such section.
Questions about who lives in By
What is the population of By?
79 at INSEE’s 2023 census, 14% more than in 2012 (69).
How old are By’s residents?
The median age is 41, younger than 73% of compared French towns. 26% are under 18 and 21% 65 or older.
How many second homes are there in By?
3, with occasional dwellings: 6.1% of all homes, against 2.1% for the median compared French town.
How many immigrants live in By?
INSEE counts 3 immigrants (born abroad, not French at birth), 3.9% of residents, and 1 foreign nationals (1.3%). The medians of compared French towns are 6.5% and 4.3%.
Sources: INSEE, census 2023 (population, ages, households, homes, marital status, diplomas, immigrants, foreign nationals, employment), 2026 geography · INSEE, Filosofi 2023 (standard of living, poverty) · IGN Admin Express (boundaries) · Medians and percentiles: TownRatings, over compared French towns, updated November 4, 2026. Under the Licence Ouverte / Open Licence 2.0 (Etalab).
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.