Audi A1 vs Audi A3: used car comparison

Published: 7 December 2023

On the face of it, the Audi A1 and Audi A3 are similar cars, each providing premium style, tech and quality in a fairly compact package. 

So how do they differ and which one might be the better option for you? Our guide compares the latest versions of each car – the second-generation Audi A1 sold new from 2019 and the fourth-generation Audi A3 sold new from 2020.

One of the main differences between the Audi A1 and the Audi A3 is size. The A1 is a small hatchback, comparable to a Volkswagen Polo or a Ford Fiesta, while the larger A3 is a family hatchback, like a Volkswagen Golf or a Ford Focus.

The Audi A1 – or the Audi A1 Sportback, to use its full name – is a shade over four metres long and 1.7 metres wide. The A3 (again, officially called the A3 Sportback) is longer at 4.3 metres and a bit wider at 1.8 metres. There’s also another version of the A3, called the A3 Saloon. It is, as you probably guessed, a saloon rather than a hatchback, but here we’re focusing purely on the hatchback (Sportback) model.

The Audi A1 and Audi A3 have some common design themes. They’re most alike at the front, with each having a very large five-sided front grille. At the side, the A3’s extra length makes it look sleeker, even though it’s a fraction taller, and – unlike the A1 – has an extra side window behind the back door. Perhaps the biggest difference between the two is that the A1 is available with a roof in a contrasting colour, which can give it quite a different look.

A key selling point of the Audi A1 and Audi A3 is the premium feel inside. In all Audis, the quality of materials is very high and the technology is at the cutting edge.

All that said, the more affordable A1 can’t quite match the overall premium feel of the A3, mostly because of the materials used. The important bits that you touch regularly still feel reassuringly solid in the A1, but other areas lower down in the cabin don’t have the softer, plusher feel that you find all over the A3.

The infotainment systems in the Audi A1 and Audi A3 are both stylish and easy to use, but there are some differences. Most A1 models have a 9.0-inch screen in the centre of the dashboard, although some have an upgraded 10-inch screen.

The A3 includes a 10.1-inch screen as a standard feature and, because the A3 was released later, the system is more advanced. Some A3 models even have an upgraded 12.3-inch screen. Apple CarPlay and Android Auto are included on both, as are several USB ports for connecting and charging your mobile devices.

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The Audi A1 and Audi A3 are both practical cars with decent boots but it’s no surprise that the larger A3 has more space for both people and luggage.

You get a 380-litre boot in the A3 Sportback, about the same as in a Ford Focus or a Volkswagen Golf. Plug-in hybrid versions, however, have a 280-litre capacity (about the same as a Ford Fiesta or Volkswagen Polo) because of where the battery pack is located. Sporty S3 models also have a smaller boot, down to 315 litres, because of their four-wheel-drive system.

The A1 has a 335-litre boot, which is very impressive for a car this size.

Both cars will seat four adults, although they’ll have considerably more legroom in the A3. You could squeeze a fifth passenger in the middle back seat of the A3, although there’s not much foot space for their feet. The middle seat in the A1 is fine for kids but too small for most grown-ups.

The Audi A1 and Audi A3 both feel solid and reassuring to drive and some versions are quite sporty. The A3 gives you a broader range of power options to choose from, including petrol, diesel and plug-in hybrid. The A1 only comes only with petrol power.

Because of the wider selection of trims and engines in the A3, there’s more of a difference in how each version feels but all are responsive yet comfortable on the road. The high-performance S3 models are fast, fun hot hatches.

While the A1 feels solid and will squeeze into smaller parking spots than the A3, it  isn’t as engaging as the A3.

The cost of owning either the Audi A1 or the Audi A3 will depend on the spec of the model you’re interested in, how old it is and how many miles it has on the clock. As a general rule, the A3 will cost more to buy and run, but there’s more of a crossover between the two than you might expect, because of the A3’s larger model range.

For example, you can actually get better fuel economy from the most- efficient A3s than from any A1, particularly the diesel models and plug-in hybrid (if you use them in the most efficient way). The most fuel–efficient A1 promises 53mpg, according to official figures, while you’ll get up to 55mpg from the most fuel-efficient petrol A3 and 61mpg from the most fuel-efficient diesel.

Insurance, too, starts at just group 14 for the A3 and group 16 for the A1. However, top-end A3 models (such as the S3) will cost more to insure than the top-spec A1.

Generally, in like-for-like models, the A1 will cost a bit less to buy and run than the A3, but if you’re careful with the exact model you choose, you could run an A3 for less.

Both the Audi A1 and the Audi A3 were awarded maximum five-star safety ratings by the safety organisation Euro NCAP. This means that the cars should protect occupants very well in a crash and come with loads of driver-safety features including automatic emergency braking and lane-departure warning.

Audi’s cars have a high-quality feel but the brand ranked 22nd out of 24 in the J.D. Power 2019 Vehicle Dependability Study – below Mercedes-Benz, but ahead of BMW.

Audi A1 Sportback

Length: 4,029mm

Width: 1,940mm (including door mirrors)

Height: 1,409mm

Boot space: 335 litres

Audi A3 Sportback

Length: 4,343mm

Width: 1,984mm (including door mirrors)

Height: 1,430mm

Boot space: 380 litres

The Audi A1 and the Audi A3 both offer a premium experience in a car that’s compact and, in most versions, cost-effective. Both have sleek looks, very good quality interiors and some class-leading interior technology.

However, the broad range of Audi A3s available gives it a wider appeal, with more engine options and more models to choose from than the A1. It’s also larger, which gives you extra practicality, and it’s more fun to drive. We think the A3 is the car that will appeal to most people, but we certainly won’t criticise anyone opting for the A1 – it’s a great little car.

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