How does Gmail email clipping affect email deliverability and open rates?

Key findings

• Size limit: Gmail clips emails that exceed roughly 102KB in HTML size, regardless of content, due to embedded code or images.
• Impact on open rates: When an email is clipped, the tracking pixel, often placed at the bottom, may not load, leading to inaccurately low reported open rates. Learn more about how accurate email open rates are.
• Deliverability risk: Clipped emails can indirectly harm deliverability. If recipients cannot easily find the unsubscribe link, they are more likely to mark the email as spam, negatively impacting your sender reputation and future inbox placement.
• User experience: Requiring users to click to view the entire message creates a poor user experience, potentially leading to lower engagement with your content and calls to action.
• Content visibility: Key information, promotions, or calls to action located lower in the email may be missed entirely if the email is clipped and the recipient does not click to expand.

Key considerations

• Monitor email size: Regularly check the HTML size of your email campaigns to ensure they stay below the 102KB threshold to avoid clipping.
• Optimize HTML: Implement clean coding practices, remove unnecessary whitespace and comments, and avoid injecting redundant code from email service providers to reduce HTML email file size. For more on hidden factors impacting deliverability, read our guide on why your email deliverability rate is wrong.
• Strategize unsubscribe placement: Ensure your unsubscribe link is visible even if the email is clipped, perhaps by placing it higher in the email or relying on the List-Unsubscribe header.
• Optimize tracking pixel location: If possible, configure your email service provider to place the open tracking pixel closer to the top of the email to ensure it loads even if the email is clipped. For further reading, an article from Klaviyo provides insight into why emails are clipped.

Key opinions

• Lower open rates: Marketers frequently observe a sharp decline in reported open rates when their emails are clipped, attributing this to the tracking pixel not loading.
• Increased spam complaints: A common concern is that if the unsubscribe link is hidden due to clipping, recipients resort to marking the email as spam, which directly harms deliverability. This behavior contributes to emails going to spam.
• Negative engagement cycle: Clipping reduces overall engagement, which in turn can negatively affect long-term deliverability by signaling to ISPs that your content is less relevant or desirable.
• Hidden calls to action: Important marketing messages and calls to action often go unseen, diminishing campaign effectiveness and potential conversions.

Key considerations

• HTML size management: Prioritizing lean HTML code and optimizing images are crucial steps to stay under the 102KB limit. Consider how email image sizes affect deliverability.
• Unsubscribe visibility: Always ensure unsubscribe links are easily accessible, either by placing them near the top or ensuring the List-Unsubscribe header is properly configured.
• Tracking pixel placement: If your ESP allows, move the tracking pixel to the top of the email to ensure open rates are tracked accurately even when clipping occurs. Further insights on how email tracking pixels affect deliverability are available.
• Testing is key: Before sending, test your emails across different clients, including Gmail, to identify and rectify any clipping issues. EmailTooltester.com offers practical advice on how to prevent Gmail clipping.

Key opinions

• Indirect deliverability impact: While clipping itself doesn't directly trigger spam filters, the resulting negative user experience (e.g., difficulty unsubscribing) leads to increased spam complaints, which then severely impacts sender reputation and deliverability.
• Open tracking pixel issues: Experts confirm that if the open tracking pixel is located within the clipped portion of an email, it will not load, leading to a significant underestimation of actual open rates. Learn more about email tracking pixels.
• User intent: Recipients who cannot easily find an unsubscribe link are more likely to use the report spam button, which is a strong negative signal to ISPs.
• Engagement metrics: Clipping contributes to lower engagement rates, which are critical factors in how ISPs (including Gmail) evaluate sender reputation and ultimately, inbox placement.

Key considerations

• Optimize email size: Focus on efficient HTML coding to keep emails under Gmail's 102KB limit. This includes reducing unnecessary code, optimizing images, and avoiding hidden elements. Consider our guide on how to reduce HTML email file size.
• Prioritize unsubscribe links: Implement a prominent unsubscribe link at the top of the email or ensure your email service provider supports the List-Unsubscribe header (post method) to give recipients easy opt-out options. Gmail's Manage subscriptions feature also helps.
• Strategic pixel placement: If possible, adjust the placement of your tracking pixel within the email template to ensure it loads even if the message is clipped by Gmail.
• Continuous monitoring: Regularly monitor your Gmail Postmaster Tools data for spam rates and engagement to identify any potential issues related to clipping. Refer to our ultimate guide to Google Postmaster Tools.
• Consider alternatives: For very long content, consider using a summary in the email and linking to a full web version to avoid clipping, as suggested by Email on Acid.

Key findings

• Fixed size limit: Gmail's clipping threshold is a fixed limit of approximately 102KB for the entire HTML content of an email, including all code and images.
• User experience focus: Clipping is implemented by Gmail to enhance user experience by reducing initial load times and data usage, preventing very large emails from overwhelming recipients.
• Tracking pixel interference: Many tracking pixels are located at the end of the email's HTML, making them susceptible to being clipped and thus preventing their execution, leading to inaccurate open rate data.
• Hidden content impact: Any content, including unsubscribe links, legal disclaimers, or calls to action, that falls beyond the 102KB limit becomes hidden, requiring an additional user action to reveal.

Key considerations

• Code optimization: Documentation often recommends minifying HTML, removing unnecessary attributes, comments, and inline CSS to reduce overall file size and prevent clipping.
• Image optimization: Large images embedded within the HTML or base64 encoded images can quickly bloat email size. Utilizing externally hosted, optimized images is advised. Our page on self-hosting email images offers more details.
• Critical content placement: Ensure the most important content and any necessary legal links (like unsubscribe options) are positioned within the initial visible portion of the email.
• Test environments: Utilize testing tools or send preview emails to Gmail accounts to confirm that your messages are not being clipped before sending to a wider audience. Email on Acid explains how to avoid Gmail email clipping.