Gmail annotations

Gmail annotations help you grab attention in the Promotions tab even before recipients open your email. You can use annotations to highlight deals, show product images, or display promo codes and prices directly in the inbox.

This article explains what Gmail annotations are, how they work, and how they can improve your email performance.

What Gmail annotations do

Gmail annotations let you add rich content to your promotional emails in Gmail's Promotions tab. Instead of showing just the subject line and preview text, you can also include:

• Limited-time offers or discounts.
• Product images or carousels.
• Promo codes and sale prices.
• Start and end dates to create urgency.

Instead of showing only your subject line and preview text, your email could also display something like "25% off + free shipping" and a product image. These elements give recipients more information upfront and make your emails more noticeable.

How Gmail displays annotations

Annotations appear only in the Promotions tab in Gmail on mobile devices.

Gmail uses machine learning to decide which emails get annotated. This means:

• You need to be on Gmail’s allowlist for annotations to display at all.
• Your email must meet Gmail’s content and quality requirements.
• Gmail can extract content to show annotations on its own, even if you don't set them up.
• Annotations aren't guaranteed to show every time. However, well-structured and relevant annotations are more likely to appear.

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Important

You can't track how often Gmail mobile promotion annotations display or measure their impact on open and click-through rates.

Choose the right annotation type

Choose the format that fits your campaign goals. Gmail supports 3 main types of annotations.

Deal annotations

• Best for: Limited-time offers, discount codes, and flash sales.
• Example: A shoe store highlights "Flash sale: 48 hours only" with their "FLASH20" promo code and countdown timer.

Single image annotations

• Best for: Featured product launches, main promotional items, brand campaigns.
• Example: A cosmetics brand showcases its new skincare line with a high-quality product image and a special price.

Product carousel annotations

• Best for: Multiple product promotions, collections, and catalogs.
• Example: A home decor store displays its top 5 bestselling items, letting customers browse products from their inbox.

Common use cases

Annotations work best for high-impact campaigns like new launches or seasonal promotions, especially when you send emails to large groups (100+ recipients). You can use them to:

• Highlight seasonal promotions with images and discounts.
• Promote new arrivals or bestsellers with pricing details.
• Feature weekend sales using promo codes.
• Add urgency with countdown timers or sale deadlines.

If you send few campaigns or rarely promote products, annotations might not be worth the effort.

Key benefits

When used well, annotations can:

• Increase visibility by adding rich visuals.
• Improve engagement by showing more offer details.
• Drive more clicks and boost campaign ROI.
• Help you stand out from competitors in the inbox.
• Improve the customer experience by giving people the info they need faster.

Understand the limitations

Before planning annotation campaigns, know these key limitations.

Technical requirements

• Mobile only: Annotations show only in Gmail’s Promotions tab on mobile devices.
• Gmail allowlist required: You must be approved by Gmail (a pre-approved list of senders) before any annotations will work.

Display and tracking challenges

• No guarantees: Gmail decides if and when annotations appear.
• No tracking: You can't measure annotation display rates or their impact on performance.
• Strict quality rules: Gmail enforces standards for content and images. Follow Gmail's best practices for content quality and structure.

Get started with annotations

Follow these steps to begin using Gmail annotations:

1. Request allowlist approval from Gmail (processing takes 7–10 business days).
2. Plan a simple campaign using deal annotations.
3. Review the technical implementation guide for setup instructions.
4. Test your annotated emails and compare results with your regular campaigns.

Annotations can be a powerful way to improve performance. Start small, validate what works, and build from there.