Two audio systems are available for the GLA, depending on the buyer's budget: Audio 20 CD (standard) and the fully integrated COMAND Online multimedia system. The radio aerials are integrated in the rear spoiler. The Drive Kit Plus for the iPhone^® and the Digital Drive Style app allow seamless integration of an iPhone^® into the vehicle.

The standard specification includes the Audio 20 CD system. It features a twin tuner, mp3-capable CD player and a USB connector in the centre console. The colour display has a diagonal of 14.7 centimetres. Thanks to a "cover art" function, the title images of the music albums currently being played are shown when their details are stored in the audio file.

An upper line in the Audio 20 CD's menu navigation makes orientation easier and can be operated via the controller. The settings for the air conditioning system are also displayed on the telematics screen (when in use), as is the fuel consumption over the past 15 minutes. There is a host of Bluetooth^® functions as well: the mobile phone's directory can now be automatically transferred en bloc when connected, and wireless music reproduction is possible from Bluetooth^®-capable devices. Text messages can also be shown. Six loudspeakers with a total output of 100 watts are also part of the standard specification.

As an optional extra, Audio 20 CD can be combined with a 6-disc CD changer, Media Interface, harman/kardon^® sound system, Convenience Telephony in the armrest, digital radio (DAB) and the Becker^® MAP PILOT entry-level navigation solution. The Becker^® MAP PILOT makes a low-cost navigation function, which can also be retrofitted, available for the Audio 20 CD. Its advantages over aftermarket solutions include integrated operation via the central controls, voice output via the vehicle's loudspeakers, display on the Audio 20 screen, a concealed location in the glove compartment and updating via an internet portal.

Mercedes-Benz developed the "Logic7" surround-sound system together with audio specialists harman/kardon^®. This high-end system delivers three-dimensional sound as a natural 360-degree musical experience for all passengers. The audio signals are distributed via a 450-watt multi-channel DSP amplifier connected to twelve high-performance loudspeakers. In conjunction with COMAND Online a multichannel listening experience with Dolby Digital 5.1 and DTS is possible.

The Media Interface is available as an optional extra. The universal interface enables mobile audio devices such as an mp3 player or iPod^® to be connected to the vehicle's telematics system. These devices are then operated via the head unit, the central control unit or the steering wheel buttons. By making use of USB 2.0, the new generation of the Media Interface provides a quicker display and an expanded data selection.

Daimler's Digital Drive Style app concept together with the Drive Kit Plus for the iPhone^® allows seamless integration of an iPhone^® into the vehicle. Highlights include Siri voice control and Glympse real-time location sharing. Glympse enables the user to share his or her current location with selected persons. Additional functions include Facebook^®, Twitter^®, internet radio, AUPEO!™ personal radio and the advanced navigation system from Garmin^® with internet-based real-time traffic information, an online POI search function including Street View™ and a 3D map display.

The high-end multimedia system is called COMAND Online. The latest generation offers improved map display, an additional Bluetooth^® profile (to enable the internet to be accessed via iPhone^®, for example), the display of images additionally in bmp and png formats and the real-time transfer of traffic data.

COMAND Online provides internet access. Customers can either browse freely when the vehicle is stationary or call up a Mercedes-Benz app with pages that load extremely quickly and are also easy to use while driving. The integrated apps include Google™ Local Search and weather as well as the option of downloading a route previously configured on the PC using Google Maps and sent to the vehicle. Apps for Google™ Street View and Google™ Panoramio also are available. With Street View, places all over the world can be viewed from a 360-degree perspective and at street level. Panoramio provides access to millions of photos taken at places around the globe by other users and made available by them. Street View and Panoramio enable users to collect comprehensive information about destinations and points of interest before the journey begins. With the News app, news from politics, business and technology can be obtained online in the vehicle. The news is displayed in a way that makes it particularly easy to read. Via the Mercedes online shop () further apps, such as stock market news or a parking space finder, can also be accessed.

The high-resolution colour display has a diagonal of 17.8 cm. The background colour of the central display is silver grey. The large screen can display photos and allows manual scrolling similar to a slide show. Where the audio equipment is concerned, too, new forms of visualisation bring a fresh look and more convenient operation. The CoverFlow function, for instance, sorts the cover images of the stored music albums in carousel-like form so that GLA‑Class drivers can easily scroll through their music collection. This collection may be very large as there are 10.8 gigabytes of memory available for compressed audio files mp3, wma, aac).

Greatest convenience is afforded by the Music Search function, which enables drivers and passengers to search the hard disc, SD memory cards, USB sticks, CDs and DVDs for specific music tracks and artists. The search can be according to various criteria, for instance album, music category or composer. If a name needs to be entered, the software will also tolerate spelling mistakes. The driver is therefore able to devote their full attention to the traffic. As a further advantage, the occupants are able to search all the connected media and devices simultaneously.

The fast hard-disc navigation of COMAND Online offers a 3D display with modelled city views. Also practical: driven routes can be recorded and retraced again later, specific personal destinations can be stored or imported via an SD card, plus four alternative routes can be displayed on the navigation map, including a particularly economical variant. Mercedes-Benz customers in Europe receive the latest map updates for their COMAND Online multimedia system free of charge for three years. Authorised Mercedes-Benz dealers will upload updates for navigation data in 39 European countries into the navigation system as part of a visit to the dealership.

In Europe, COMAND Online also comprises Speed Limit Assist, which receives its information for traffic sign recognition via a camera and the navigation database. COMAND Online also includes the LINGUATRONIC voice-operated control system for audio, telephone and navigation. The new "one shot" input function for the navigation system is particularly convenient, allowing the place and road to be spoken directly after one another. This function is currently available in seven languages and significantly enhances ease of operation.

With COMAND Online and LINGUATRONIC, in the GLA-Class music can also be easily searched for using voice control. The system first asks in which category it should conduct the search (artist, title, year). The category is selected by speaking it out or by speaking the row number of the relevant category which appears on the screen. This is then followed by further questions about title, artist or album.