GDN vs. LINE Yahoo Ads (Formerly YDA): Features, Surfaces, and How to Use Them

When you set out to run display advertising, two ad networks almost always come up: Google's "GDN" and the display advertising of Yahoo! and LINE. The latter was reborn under the name "LINE Yahoo Ads Display Ads (formerly YDA)" through a merger in April 2026. Both are major delivery destinations, but many people are unsure "what actually differs" and "which one should we use." This article explains what GDN is from the basics, how it differs from LINE Yahoo Ads, the features and delivery surfaces of each, and how to use them in practice.

What is GDN?

GDN stands for "Google Display Network," a display advertising menu you can run from Google Ads. Its feature is that you can display ads on a very large number of sites and apps partnered with Google, including Google services such as YouTube and Gmail, as well as everything from individual blogs to major media.

Whereas listing ads (search ads) appeal with text to "users who are searching right now," display ads such as GDN play a major role in being able to reach broadly, using images and video, even potential users whose needs have not yet surfaced.

What is LINE Yahoo Ads Display Ads (formerly YDA)?

LINE Yahoo Ads Display Ads is a display advertising menu that can show ads on the delivery surfaces of Yahoo! and LINE. It was born on April 1, 2026, when the previously separate "LINE Ads" and "Yahoo! Ads Display Ads (YDA)" were merged.

"YDA" was originally the name for Yahoo! Ads' display advertising (operated type), and its predecessor before that was YDN (Yahoo! Display Network). Because the name changed from YDN to YDA in 2021, and then to LINE Yahoo Ads in 2026, the name "YDA" still lingers today. This article also includes the often-searched notation "formerly YDA."

What changed in the April 2026 merger

Through the merger, in addition to the existing Yahoo! JAPAN surfaces, cross-delivery to LINE surfaces became possible, and delivery data can now be managed centrally in a single dashboard. The dashboard UI is based on the former YDA's specifications, so it is said that the operational feel does not change much for those who used Yahoo! Ads. On the other hand, if you were using the former LINE Ads, account migration may be required in some cases, so it is important to check what action is needed based on your own usage situation.

Main differences between GDN and LINE Yahoo Ads

The biggest difference between GDN and LINE Yahoo Ads is the "place (delivery surface)" where ads appear and the "user base." Because Google and Yahoo!/LINE partner with different websites and have users with different attributes, the targets they each excel at differ. Let's look at the main differences from three points: "delivery surfaces," "targeting," and "ad size/format."

Differences in delivery surfaces (delivery media)

In addition to Google's own services such as YouTube and Gmail, GDN can deliver ads to an enormous number of partner sites and apps, including individual blogs. The number of delivery media is very large, and its strength is the breadth of reach. LINE Yahoo Ads, on the other hand, can deliver to Yahoo! JAPAN and Yahoo! News, as well as partner sites such as Tabelog and Ameba, and to LINE surfaces. Its feature is being able to reach mainly the platform surfaces of Yahoo! and LINE, which have many users in Japan.

Differences in targeting

Both can target based on user attributes, interests, past behavior, and so on, but the underlying data differs. GDN can leverage behavioral data from the Google ecosystem such as Google Search and YouTube, while LINE Yahoo Ads can leverage usage data from Yahoo! Search and LINE, so compatibility varies depending on the audience you want to reach. With the post-merger LINE Yahoo Ads, combining LINE and Yahoo! data is expected to improve the accuracy of machine learning.

Differences in ad size and format

Both GDN and LINE Yahoo Ads support text, image, and video formats, but the regulations for the banner sizes you can submit differ. In general, GDN tends to support more types of image sizes, making it easier to deliver across a wider variety of ad slots. Also, GDN recommends "responsive display ads," in which you submit multiple texts and images and AI automatically displays the optimal combination.

Cases suited to GDN, cases suited to LINE Yahoo Ads

Which to choose is basically judged by the user base you want to target and the delivery surface you want to reach.

• Cases where GDN is suitable: when you want to reach as many users as broadly as possible, when you want to leverage Google service surfaces such as YouTube, and when you want to deliver efficiently with diverse image sizes and responsive ads.
• Cases where LINE Yahoo Ads is suitable: when you want to appeal to the user base of Yahoo! JAPAN and Yahoo! News, as well as LINE users. It suits reaching a wide range of ages in Japan, search/news readers, and users of the communication app.
• Using both together: if you have budget to spare, using both together to complement delivery surfaces is effective. While suppressing overlap, you can reach more potential customers.

Points for using them appropriately

In practice, it becomes easier to choose if you first consider whether your target audience uses the Google ecosystem or Yahoo!/LINE more. For example, GDN including YouTube for appealing to younger audiences and video viewers, and LINE Yahoo Ads for a wide range of ages or readers of LINE and Yahoo! News, are strong options. On top of that, start delivering on a small scale, and while watching the data, shift budget toward high-performing delivery surfaces and targeting, which makes it easier to maximize results.

Note that GDN also delivers ads on app surfaces, so if you want to exclude apps with low relevance, such as for business-user targeting, excluding app surfaces in advance tends to improve results. Also, with LINE Yahoo Ads, since the merger has made it possible to handle LINE surfaces and Yahoo! surfaces together, it is good to check in reports which surface is performing and use that for delivery adjustments. Performing such exclusion settings and checking delivery surfaces periodically is, alongside choosing the right tool, an important operational point.

Summary

GDN is the abbreviation for Google Display Network, with the strength of broad reach to an enormous number of partner sites including YouTube and Gmail. LINE Yahoo Ads Display Ads (formerly YDA), on the other hand, is a menu born from the merger of the former YDA and LINE Ads in April 2026, with the feature of being strong on large domestic platform surfaces such as Yahoo! JAPAN and LINE. Because the two differ in delivery surfaces and user base, it is effective to use them appropriately according to your target, or to use them together to complement each other. In particular, build your strategy taking into account the latest specifications, in which delivery to LINE surfaces has become possible.