Photo: Langladure · CC BY-SA 3.0Less crime per resident is recorded in Guyancourt than in 90% of the 270 compared French towns closest in size
Across all the graded crimes, Guyancourt lands on B (#44 of 91 in Yvelines): close to the middle of compared French towns, on offenses police and gendarmerie recorded from 2023 to 2025. The crimes the grade counts held steady per resident from 2023 to 2025. Theft of vehicle parts runs at 3.1 per 1,000 residents here, against 1.3 in a typical town its size: police and gendarmerie recorded 92 in 2025. Behind the grade sit 7.5 violent crimes and 12.1 incidents of burglary, vehicle theft and damage per 1,000 people a year.
Offenses recorded per 1,000 residents a year, 2023–2025 average (INSEE population of each year). Violence, and burglaries, vehicle thefts, thefts from vehicles and criminal damage, count equally.
What stands out about safety in Guyancourt
Counted where it happens
37,550 jobs are based in Guyancourt, for 13,800 working residents. Offenses are counted in the commune where they happen, then divided by its number of residents, so a town people come into for work and shops records more per resident than one they leave. How to read it ↓
Among towns its size
Among the 270 French towns of 20,800 to 40,200 people with a Safety Grade, Guyancourt is 28th from the lowest recorded rate per resident. Towns its size ↓
Written from the SSMSI and INSEE data on this page. Figures are offenses police and gendarmerie recorded, not convictions.
The B for Guyancourt, and how it is built
A firm grade. Built on 1,751 offenses recorded in the graded categories over three years; with a town of 29,778, a few cases more or fewer would move it between B and B.
Hidden counts: for armed robbery, this figure isn’t published when it’s small (five or fewer in at least one of the last three years); the index uses the département’s average instead, 0.2% of the index here. What isn’t published ↓
Per resident, against the 4,295 compared French towns with a Safety Grade.
28th of 270: Guyancourt among towns its size
| # | Town | People | Violence | Homes, vehicles | Safety |
|---|---|---|---|---|---|
| 1 | Beaupréau-en-Mauges Maine-et-Loire | 23,989 | 5.4 | 8 | A |
| … | |||||
| 12 | Le Chesnay-Rocquencourt Yvelines | 30,689 | 5.4 | 11.9 | B+ |
| 13 | Chatou Yvelines | 30,598 | 4.6 | 12.9 | B+ |
| … | |||||
| 17 | Rambouillet Yvelines | 27,724 | 7.4 | 10.8 | B+ |
| 18 | Carrières-sous-Poissy Yvelines | 20,825 | 7.2 | 11.1 | B+ |
| … | |||||
| 25 | Plaisance-du-Touch Haute-Garonne | 21,079 | 5.9 | 13.7 | B |
| 26 | Élancourt Yvelines | 26,365 | 8 | 11.6 | B |
| 27 | Saint-Médard-en-Jalles Gironde | 32,910 | 5.9 | 13.7 | B |
| 28 | Guyancourt Yvelines | 29,778 | 7.5 | 12.1 | B |
| 29 | Yerres Essonne | 27,906 | 5.8 | 14 | B |
| 30 | La Garenne-Colombes Hauts-de-Seine | 30,197 | 5.5 | 14.5 | B |
| 31 | Montigny-lès-Metz Moselle | 21,718 | 6.9 | 13.1 | B |
| … | |||||
| 270 | Marseille 2e Bouches-du-Rhône | 24,378 | 20.1 | 103.2 | D− |
Per 1,000 residents a year. Context only: the grade compares Guyancourt with every compared French town, not just towns its size.
Lowest rate in the graded categories first, 2023–2025 average, with the closest to Guyancourt and up to four from Yvelines.
What police and gendarmerie recorded most in 2025
Well above the median of towns its size: theft of vehicle parts (3.1 per 1,000 against 1.3). Not published for 2025: armed robbery.
Theft without violence, robbery without a weapon, theft of vehicle parts, fraud and drug offenses are shown for information but left out of the Safety Grade, which counts violence plus burglaries, vehicle thefts, thefts from vehicles and criminal damage per resident.
Per 1,000 residents in 2025; the tick is the median of the graded French towns of 10,000 to 50,000.
Guyancourt, year by year
Violence · per 1,000 residents
Burglary, vehicle theft, damage · per 1,000 residents
| Kind | In the grade | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| Family violence | Violence | 124 | 74 | 138 |
| Other physical violence | Violence | 60 | 82 | 75 |
| Sexual violence | Violence | 29 | 48 | 36 |
| Armed robbery | Violence | n.p. | n.p. | n.p. |
| Burglary | Burglary, vehicle theft, damage | 42 | 54 | 43 |
| Vehicle theft | Burglary, vehicle theft, damage | 59 | 48 | 48 |
| Theft from vehicles | Burglary, vehicle theft, damage | 42 | 56 | 45 |
| Criminal damage | Burglary, vehicle theft, damage | 247 | 213 | 188 |
| Theft without violence | Not in the grade | 170 | 175 | 164 |
| Robbery without a weapon | Not in the grade | 13 | 10 | 8 |
| Theft of vehicle parts | Not in the grade | 16 | 67 | 92 |
| Fraud | Not in the grade | 214 | 196 | 187 |
| Drug use | Not in the grade | 153 | 196 | 97 |
| Drug dealing | Not in the grade | 9 | 24 | 9 |
Counts mix units, as SSMSI publishes them: victims for violence, offenses for burglary and damage, vehicles for vehicle theft. That’s why the page never adds them into one “total crimes”.
Offenses recorded each year. n.p.: not published (small: five or fewer in at least one of the last three years).
Crime in Guyancourt per 1,000 residents
Each dot is one resident’s share: offenses are counted, not victims, and one person can be the victim of several.
And 12 burglaries, vehicle thefts, thefts from vehicles and acts of criminal damage, and 12 thefts without violence and frauds: a year, 2023–2025 average.
Guyancourt and the towns around it
| Town | People | Violence | Homes, vehicles | Safety |
|---|---|---|---|---|
| Guyancourt | 29,778 | 7.5 | 12.1 | B |
| Voisins-le-Bretonneux | 10,624 | 4.3 | 12.3 | B+ |
| Montigny-le-Bretonneux | 32,465 | 7.2 | 11.9 | B |
| Saint-Cyr-l'École | 21,268 | 8.7 | 12.8 | B− |
| Buc | 5,816 | 4.6 | 13 | B+ |
| Fontenay-le-Fleury | 13,680 | 6.9 | 10.8 | B+ |
| Bois-d'Arcy | 16,586 | 8.4 | 13.9 | B− |
4 of its 6 graded neighbors have a lower recorded rate in the graded categories than Guyancourt.
The nearest towns of 2,500 or more, per 1,000 residents a year, 2023–2025 average.
What this data can and can’t tell you
- Where offenses happen, not where victims live. SSMSI counts each offense in the commune where police or gendarmerie recorded it happening. Towns with shops, stations, a hospital or nightlife record more per resident, and visitors are part of that count but not of the population it is divided by.
- An index, not a total. The kinds are counted in different units (victims, offenses, vehicles), so the grade adds their rates per 1,000 residents into an index and never shows a “total crimes” or a chance of being a victim.
- Hidden counts. SSMSI doesn’t publish a commune’s count when it’s small (five or fewer in at least one of the last three years). In its place it gives the average among the département’s communes whose count is hidden; the grade uses that average, never zero, and a town gets no Safety Grade when over a quarter of its index would come from such averages.
- Recorded, not all crime. Only offenses reported to or found by police and gendarmerie are counted. Reporting rates differ by kind: most vehicle thefts are reported, much family and sexual violence isn’t.
Questions about safety in Guyancourt
Is Guyancourt safe?
It has less crime per resident than 58% of compared French towns: an average of 7.5 recorded violent incidents and 12.1 recorded burglaries, vehicle thefts, thefts from vehicles and acts of criminal damage per 1,000 residents a year, 2023–2025. It grades B for safety, #44 of 91 in Yvelines. Among the 270 French towns of 20,800 to 40,200 people, it is 28th from the lowest rate. With 37,550 jobs for 13,800 working residents, Guyancourt draws people from neighboring communes, and crimes are counted in the commune where they happen, then divided by its number of residents.
Is crime going up in Guyancourt?
The recorded rate in the graded categories held steady from 2023 to 2025: 20.3 per 1,000 residents in 2023, 19.3 in 2025. The grade uses the three-year average, so one unusual year moves it less.
What is the most common recorded offense in Guyancourt?
Criminal damage: 188 in 2025. Then fraud (187), theft without violence (164) and family violence (138).
Sources: SSMSI (Interior Ministry), recorded crime by commune, 2023–2025 (base communale de la délinquance enregistrée, 2026 edition) · INSEE, legal populations for each year · INSEE, census 2023 (jobs and working residents) · IGN Admin Express (boundaries) · TownRatings grades: our own summary of the data, ranking French towns against each other only, 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.