How do you write a call to action for a video ad?

What is a call to action in a video ad?

A call to action (CTA) in a video ad is a clear prompt designed to guide viewers toward a desired next step. For example, Google Ads states that ads in a campaign can use a call-to-action, along with a headline and description, as part of the creative. These campaigns, known as Video Action Campaigns, are described as a simple and cost-effective way to drive more conversions both on and off YouTube.

The purpose of a CTA is to encourage viewers to click, subscribe, or visit a page. YouTube, for instance, suggests encouraging viewers to click using calls to action for different end screen elements. This direct instruction helps translate viewer interest into measurable actions.

How do calls to action appear on different platforms?

Ad platforms provide multiple ways to present calls to action within video ads. Google Ads, for example, allows ads in a campaign to include a call-to-action, a headline, and a description as part of the creative. This means the CTA can be integrated directly into the ad's text elements.

For specific placements, Google Ads has introduced QR Codes for performance advertising on Connected TV (CTV). These QR codes offer an additional option beyond the standard call to action buttons. On TikTok, for Automotive Ads, clicking the end card or final slide will take a user to browse a full inventory, either on a Vehicle Inventory Page or a URL of their choice. YouTube also uses end screens to promote other videos or encourage viewers to subscribe.

What are the text requirements for calls to action?

When creating video ads, the text used for calls to action and headlines has specific length requirements. Google Ads states that ads in a campaign can use a call-to-action, a headline, and a description. The length of the headline depends on where the ad will appear.

For example, Google Ads specifies that a headline of 30 characters or less will run on in-stream inventory. If the ad is displayed on in-feed inventory, a longer headline of 90 characters or less can be used. These varying limits help ensure the text fits appropriately within different ad formats and placements.

How do end cards work in video ads?

TikTok documents that for Automotive Ads, an end card is different from product images and is displayed at the end of a carousel or product card list. Typically, a logo or graphic is used in this slot. Clicking this final slide or end card directs a user to browse a full inventory, either on a Vehicle Inventory Page or a chosen URL.

YouTube also utilizes end screens. These end screens can promote other videos, encourage viewers to subscribe, or link to an external website if the creator is in the YouTube Partner Program. To use an end screen, a video must be at least 25 seconds long. For videos with a standard 16:9 aspect ratio, up to four elements can be added to the end screen, and YouTube encourages using calls to action for these elements. End screens are not available for videos marked as "made for kids," in the YouTube Music app, flash videos, mobile web, or 360 videos.

• TikTok end cards are displayed at the end of a carousel or product card list.
• A video must be at least 25 seconds long to have a YouTube end screen.
• YouTube end screens can include up to four elements for standard 16:9 aspect ratio videos.
• YouTube Partner Program members can link to an external website from an end screen.

What are the video and image requirements for calls to action?

Platforms have specific technical requirements for the video and image assets used in ads, especially those incorporating calls to action. For instance, TikTok Automotive Ads use a variety of images and videos. Product images for these ads should follow a 4:3 aspect ratio, with preferred dimensions of 800 by 600 pixels. It is also recommended that the image be clear, with minimal "dead space" around the vehicle to maximize its visibility. The file size for these assets should be less than or equal to 500 MB.

Video length is also a factor. Google Ads states that the video included in a campaign should be at least 10 seconds in length. For YouTube end screens, a video must be at least 25 seconds long to be eligible. Google Ads also recommends vertical videos as a best practice for creative assets in App, Performance Max, and Video campaigns. When using YouTube end screens, up to four elements can be added for videos with a standard 16:9 aspect ratio. TikTok end cards, or final slides, have specific dimensions such as 1200 by 628 pixels, 640 by 640 pixels, or 720 by 1080 pixels.

How do you measure call to action performance?

Understanding how viewers interact with calls to action is essential for optimizing ad campaigns. Google Ads measures each successful QR code scan just like a click or tap on mobile and desktop, providing clear campaign metrics. This allows advertisers to see the direct impact of their QR code CTAs.

Similarly, YouTube provides tools to check the performance of end screens. Creators can find this data on the Engagement tab of YouTube Analytics. These analytics help in evaluating which calls to action are most effective in driving viewer engagement and conversions.

Common questions

What is an aspect ratio in video ads?

An aspect ratio describes the proportional relationship between an image's width and its height. For example, TikTok product images should follow a 4:3 aspect ratio, with preferred dimensions of 800 by 600 pixels. A standard 16:9 aspect ratio is common for YouTube videos that can use up to four end screen elements.

What is a "safe zone" for video ad creatives?

While the term "safe zone" isn't explicitly defined in the facts, the concept relates to ensuring key elements are visible. For TikTok Automotive Ads, product images should be clear with minimal "dead space" around the vehicle to maximize its visibility. This implies keeping important content, like the vehicle, within a primary viewing area.

Can all YouTube videos have end screens?

No, not all YouTube videos can have end screens. End screens are not available for videos set as "made for kids," those in the YouTube Music app, flash videos, mobile web, or 360 videos. Additionally, a video must be at least 25 seconds long to be eligible for an end screen.

What are Google's Video Action Campaigns?

Video Action Campaigns (VAC) are a simple and cost-effective way to drive more conversions both on and off YouTube, all within a single automated campaign. As of May 2026, all Video Action Campaigns have been upgraded to Demand Gen. These campaigns allow ads to use a call-to-action, headline, and description.

How long should a video be for a Google Ad campaign?

For a Google Ad campaign, the video included should be at least 10 seconds in length. This minimum duration ensures there is enough time to convey the message and present the call to action effectively.