About language targeting
If you try to communicate with others who don't speak the same language, you might find it tough to get your message across. Similar to AdWords, you want your ads to appear for customers who can understand them.
Your ads can appear for customers who use Google products and third-party websites in the languages that your campaign targets. This helps ensure that your ads will appear on sites that are written in the language of the customers you'd like to reach.
Choose your target language
Language targeting allows you to choose the language of the sites that you'd like your ads to appear on. We'll show your ads to customers who use Google products (such as Search or Gmail) or visit sites on the Google Display Network (GDN) in that same language. Keep in mind that AdWords doesn't translate ads or keywords.
Let's say you sell coffee beans online, and you want to target Spanish-speaking customers. You set up an AdWords campaign targeted to the Spanish language, with Spanish ads and keywords. As long as your customers' Google interface language settings are set to Spanish, your coffee ads can show when your Spanish language customers search for your keywords. Keep in mind that if your customers searched in Spanish but their Google interface language settings were set to English, your ads wouldn’t show. That's why targeting all languages might be helpful.
Target languages on the Search Network
Unless you only want to show your ads to people who speak a single language, you might find it helpful to target all languages. By targeting all languages, you can reach people who speak more than one language and may search in several languages. Let’s say someone speaks English and Spanish but set their Google interface language setting to Spanish. It’s possible that person may also search for something in English, like “buy shoes online.” If you have a campaign with these English keywords targeting the English language, that person wouldn’t see your ad. That’s why targeting all languages can help you reach more potential customers.
Keep in mind that targeting all languages isn’t always the best approach. If you have an ad with a word like “hotel” that’s spelled the same in many languages, you shouldn’t target all languages. Otherwise, people who may not understand the language your ad is written in might still see it. If you want to show this type of ad in multiple languages, we recommend creating separate campaigns for each language. That way you can make sure the language you target is the same as the language your ad is written in.How AdWords detects languages
On the Search Network
Each Google domain has a default language. For example, Google.com defaults to English, Google.fr defaults to French, Google.cn defaults to Chinese, and so on.
The default language can be changed via the Settings link on the Google homepage. A Spanish-speaker living in the United States, for instance, may want to perform searches on the U.S. domain, Google.com, but could change the interface language setting to Spanish. In that case, he would see ads targeting Spanish instead of English.
While your campaign always targets searches with a matching interface language, your campaign may also target searches or Google Display Network sites that we detect are written in your target language.
There are five languages that you can target within AdWords where the alphabet of the search uniquely identifies the language of the search: Greek, Hebrew, portions of Japanese, Korean, and Thai. So if you have the keyword λουλούδια (Greek for flowers) in a campaign that targets the Greek language, your ad will be eligible to appear whenever a customer searches for λουλούδια, even if the customer's interface language is set to English.
On the Display Network
On the Google Display Network, AdWords may look at the language of the pages that someone is viewing or has recently viewed to determine which ads to show. This means that we may detect the language from either pages that the person had viewed in the past, or the page that she is currently viewing.
Maya has viewed several cooking blogs on the Google Display Network that are written in Japanese, and she sees ads from campaigns targeted to Japanese speakers. She may also see Japanese ads even when she reads other blogs on the Display Network that are written in English because of her viewing history.