Writing principles

Text on car screens needs to be glanceable, consistent, clear, and relevant to the driver's situation. The following writing principles help you create driving-optimized experiences for the car.

Learn how to:

Make sure text is glanceable

Keep text simple and easy to read at a glance so drivers can keep their eyes on the road.

You should:

Make sure text is easy to scan

Whether they are driving or parked, drivers may not read every word on the screen. People tend to scan text in an F-shaped pattern.

Put the most important details first, clearly and concisely describing the action the driver needs to perform.

Organize information so it's easy to scan at a glance. For example, use spaces and bullet points to organize content.

Do Don't

Connect your phone to start

Connect your phone to start

To get started, do one of the following:

  • Tap the notification on your phone
  • Scan the QR code

Tap the notification on your phone or scan the QR code to get started. You are then guided to your car's app to complete next steps.

Use simple, direct language

Use clear, direct, and simple language. Avoid jargon or complex words, which can confuse drivers and make tasks take longer.

Do Don't

Sign in to your account

Authenticate your account

Limit text to 120 characters

Limit the amount of text drivers need to read before taking an action. This helps to reduce cognitive load so they can focus on driving. Based on guidance from NHTSA and JAMA:

  • A single message or chunk of text in English shouldn't exceed 120 characters or 24 words
  • A single message or chunk of text in Japanese shouldn't exceed 30 characters
  • The text in 1 line shouldn't exceed 80 characters
  • A sentence or paragraph shouldn't span more than 3 lines of text

This guidance doesn't apply to legal or privacy text.

Do Don't

Android Auto doesn't work with your phone

Android Auto isn't part of your phone's operating system, so it won't work with this car.

OK

Android Auto was not preinstalled on this device

Android Auto must be bundled with your operating system to work correctly. Please contact your phone manufacturer for assistance.

Try Again

Use consistent language

Consistent language helps minimize cognitive load for drivers.

You should:

Use a consistent writing style

Keep your writing style consistent throughout your app. Developing a cohesive and recognizable brand voice can help drivers navigate your app more easily.

Based on your brand's style choices, be consistent in word choice, sentence structure, capitalization, punctuation, and overall voice and tone.

Do Don't

Make buttons sentence case or title case consistently

Cancel setup

Connect another phone

Mix capitalization across buttons

Cancel Setup

Connect another device

Punctuate the end of standalone sentences consistently: period or no period

"Your phone is now connected to the car" and "You lost connection with your phone"

Mix use of periods across sentences

"Your phone is now connected to the car." and "You lost connection with your phone"

Use consistent terminology

Using different words to mean the same thing confuses drivers. Use consistent terminology across your app to ensure clarity.

Do Don't

First reference: Phone

Second reference: Connect another phone

First reference: Mobile device

Second reference: Connect another phone

Write with situational awareness

Make sure your text is relevant to the driver's needs and situation, including whether they are driving, parked, or experiencing an emergency.

You should:

Balance brevity with clarity

Text shown during driving should be brief and clear. However, it's okay to use longer explanations for complex situations — such as privacy consents, permissions, and data sharing — when the driver is parked. In those instances, break up longer text using lists and hierarchy.

Do Don't

Chromecast built-in

To use Chromecast built-in, you'll need to agree to Google's Terms of Service and Google's Privacy Policy.

Your device data ensures Chromecast built-in works as expected, and won't be used to identify you.

[I agree] [Not now]

Chromecast Terms of Service

You must agree to Google's Terms of Service and Google's Privacy Policy. Your device data won't be used to identify you.

[OK] [Cancel]

Lead with the benefit to the driver

When instructing the driver to take an action, communicate the benefit of that action first. This way drivers can quickly make a decision and return their focus to the road.

Do Don't

To connect your phone, turn on Bluetooth

Use Bluetooth to connect your phone

To sign in faster, scan the QR code

Scan the QR code to connect faster

Use reassuring tone of voice, except in emergencies

When the car is in motion, use a reassuring tone of voice to avoid distracting the driver and causing needless anxiety.

However, exceptions should be made when the driver is in physical danger and needs to take immediate action. In those cases, use direct instruction and exclamation marks to convey urgency.

Do Don't

(Non emergency) New conversations are paused

(Non emergency) For your safety, all new conversations are paused!

(Non emergency) Android Auto lost connection

(Non emergency) Lost connection!

(Emergency) Brake now!

(Emergency) Take control of your steering wheel to stop collision

Follow best practices for writing component text

These best practices will help you write driving-optimized text for components like buttons, notifications, and more.

You should:

Make button text brief and actionable

Button labels (also known as CTAs or calls to action) should always start with a verb and ideally contain no more than 3 words.

Do Don't

Connect phone

Phone is ready

Download app

App listing

Provide confirmation messages

Use a confirmation message to reassure drivers when tasks they initiated are complete.

Do Don't
Dave's phone is now connected to the car's hotspot

<No confirmation message>

Provide a way to recover from errors

Error messages should state the problem clearly and offer a way out of the situation. If there's no recovery path, the message should clearly communicate that to the driver.

Do Don't

Turn on Wi-Fi to connect

Android Auto needs 5 GHz Wi-Fi support to connect

[Turn on Wi-Fi] [Not now]

Android Auto is not connected

Your Wi-Fi is turned off

[OK]

Try a new USB cable

Your phone keeps disconnecting from the car. Using a different USB cable or port could help.

Damaged USB cable detected

Android Auto has noticed an unusual number of disconnections.

Front-load critical information in notifications

Put critical information first in notifications. Avoid causing alarm to the driver in any way.

Do Don't

Focus on driving

Some new notifications are saved in the Notification Center

Notifications aren't being shown

Go to the Notification Center to see your notifications