221 hp, 4MATIC, Two Sizes: How the Mercedes-Benz GLA and GLB Actually Differ

Both the GLA and GLB wear the same three-pointed star, share a turbocharged engine family, and offer 4MATIC all-wheel drive as standard. For buyers narrowing their search within the Mercedes-Benz compact SUV lineup, those similarities make the choice feel harder than it is. The two models are actually built around different priorities, and understanding those differences makes the right pick clear.

This guide covers the key contrasts across size, cargo, passenger capacity, and everyday use, so you can walk into a conversation with a product advisor already knowing where each model fits your life.

At a Glance: GLA 250 4MATIC vs. GLB 250 4MATIC

Size and Proportions

The GLA is the more compact of the two, at 4,412 mm in length and 1,616 mm tall. Its dimensions make it quick to park and easy to navigate in tight urban environments. The lower roofline gives it a sportier silhouette and a more coupe-like character within the compact SUV segment.

The GLB is noticeably taller and longer: 4,634 mm in length and 1,692 mm in height. That upright shape is a functional choice. The added height translates directly into more headroom for all three rows, and the longer body creates the cargo floor necessary to fit a usable third row. For buyers who plan to carry four or more passengers regularly, the GLB's dimensions are doing real work.

Cargo and Practicality

The difference in cargo capacity between the two models is clear on paper and even more apparent in everyday use.

The GLA offers 435 L of cargo space with the rear seats in use, expanding to 1,430 L with the 40/20/40-split rear seats folded. That is a solid result for a compact SUV, and the flexible finished cargo area handles most daily hauling tasks without issue.

The GLB starts at 570 L with the second row in use and expands to 1,805 L with all rear seats folded. For buyers who regularly move gear, sports equipment, or family luggage, that extra capacity adds up across a week of use.

• GLA 250 4MATIC: 435 L (seats up) to 1,430 L (seats folded)
• GLB 250 4MATIC: 570 L (seats up) to 1,805 L (seats folded), or approximately 179 L with optional 3rd row in place

Passenger Capacity

The GLA is a five-seat SUV, full stop. Its rear seating is well-proportioned for two adults, with 976 mm of legroom and 969 mm of headroom in the second row.

The GLB can seat five as standard, with the option to add a third row through the available 3rd-Row Seat Package, bringing total capacity to seven. The optional third row offers 740 mm of legroom and 884 mm of headroom. These dimensions are intended for occasional use and are most comfortable for younger passengers. For families with growing children or those who occasionally need to carry a larger group, the option to configure seven seats is a practical differentiator that the GLA simply cannot match.

Performance and Driving Character

Both models use the same 2.0 L 4-cylinder turbocharged engine with 48-volt mild hybrid assist, producing 221 hp and 258 lb-ft of torque, paired with an 8-speed dual-clutch automatic. Both are 4MATIC as standard.

The GLA reaches 100 km/h in 6.8 seconds, while the GLB takes 7.0 seconds. The GLA's lighter kerb weight gives it a slightly sharper feel off the line and through corners. The GLB is not slow, but its upright height and larger footprint make it feel more composed and settled at highway speeds rather than sporty.

For buyers who prefer a more dynamic feel on a daily drive, the GLA has a meaningful edge. For buyers who prioritize ride comfort and stability across longer trips, the GLB's character suits that use well.

Interior Technology

Both models share the same core technology foundation: dual 10.25-inch displays, MBUX with natural-language voice control, wireless Apple CarPlay and Android Auto, front wireless charging, and a standard panoramic sunroof with 40/20/40-split folding rear seats. Heated front seats with memory, THERMOTRONIC dual-zone climate control, and 64-colour LED ambient lighting are also standard across both.

The technology experience is effectively the same in both models. The choice between them comes down to size and how you use the vehicle, not what you want from the infotainment or driver assistance systems.

Which Model Is Right for You?

The GLA fits buyers who want a compact, agile SUV for daily urban use, value a lower ride height with a sportier profile, and do not need more than five seats. It handles parking, city driving, and commuting with less bulk and delivers the more driving-focused experience of the two.

The GLB fits buyers who need more cargo room on a regular basis, want the option to configure seven seats for occasional family use, or prefer a more upright and spacious cabin. The extra height and length are not penalties; they are the reason the GLB can do things the GLA cannot.

If the choice still feels close after reading this, the test drive is where it resolves itself. The two models feel noticeably different from behind the wheel, and most buyers leave with a clear preference.

Compare Both Models at Mercedes-Benz Brampton

The GLA and GLB are both worth experiencing in person. The team at Mercedes-Benz Brampton in Brampton can walk you through both models side by side, answer any questions on available packages, and arrange test drives for either vehicle.

Book your visit at Mercedes-Benz Brampton and see which one fits your daily routine.