Why Email Size Matters
Large emails can cause display and delivery problems. Gmail clips emails that exceed 102 KB of HTML. Other email clients may remove large images or reject the email completely. This can hide content such as CTAs, images, or disclaimers.
Keeping your email small improves:
Deliverability
Load speed
Visibility of the entire message
Check Your Email Size in the Optimize Tab
The Optimize tab helps you monitor the total email size before sending. Use this tab to confirm your email stays below the 102 KB Gmail clipping limit.
Review Email Size
Open your email in the Knak builder.
Click the Optimize tab.
Review the email size indicator.
Confirm the email size is below 102 KB.
If the email is too large, the Optimize tab will show a warning. This indicates the email may be clipped by Gmail.
Once the size is below the limit, the Optimize tab will confirm the email is optimized.
Why Your Email Size Can Increase After Export
The Optimize tab shows your email size when it leaves Knak. Gmail measures the email when it arrives in the inbox. After you export, your email platform (such as Marketo, Salesforce Marketing Cloud (SFMC), or Eloqua) adds code to your email. This can push it over the 102 kilobyte (KB) limit.
What Adds Size
Link tracking: Your platform replaces each link with a longer tracking link. This is usually the biggest cause.
Tokens and dynamic content: Placeholders like a first name field are replaced with real content at send time.
Platform code: Your platform adds items like an open-tracking pixel and an unsubscribe footer.
Inlined styles: Some platforms copy style code onto every part of your email.
Special characters: Curly quotes, em dashes (—), and emojis take up more space than plain letters.
Leave Room Below the Limit
Keep your email well below 102 KB in the Optimize tab. For example, a 96 KB email has only about 6 KB of room left. Link tracking alone can use that up.
To check the final size, send a test from your email platform to a Gmail inbox. If you see [Message clipped] View entire message at the bottom, the email is too large.
Reduce the Number of Sections
Every new section adds additional HTML. More HTML increases the total email size.
Use fewer sections when possible.
Add multiple content blocks inside the same section instead of creating new sections. Example: Place a text block directly below an image block in the same section.
Add a Content Block to an Existing Section
Click the content block you want to add.
Drag the block into the desired section.
Release the block when the blue placement line appears.
Why This Helps
All content blocks stay inside one structure.
Less structure means less HTML code.
Smaller HTML reduces email file size.
Avoid Creating Unnecessary Sections
Do not create a new section when you can add the content to an existing section.
For example, you may want to add text below an image. Avoid placing the image and text in two separate sections when they can share the same section.
Avoid:
Section 1: Image block
Section 2: Text block
Use instead:
Section 1:
Image block
Text block
This keeps your email structure simple. It also reduces unnecessary HTML.
Other Ways to Reduce Sections
You can also use these options to keep your email structure simple:
Use Nested Sections: Add a nested section inside a one-column layout when you need a more complex layout without adding another top-level section.
Use Responsive Options: Adjust how your existing content appears on mobile instead of creating separate sections for desktop and mobile.
Tip: Use Mobile Editing to adjust mobile-specific settings.
These options can help you create the layout you need while reducing unnecessary HTML.
Optimize Image Size
Images often contribute the most to email weight. Keep the total image size under 1 MB for the entire email. Large images may also impact deliverability.
Example combinations:
Number of Images | Approximate Size Each |
10 images | 100 KB each |
5 images | 200 KB each |
2 images | 500 KB each |
Reduce Image Size Before Uploading
Use an image compression tool before adding images to Knak.
Photopea
Free online image editor
Reduces image size and dimensions
Link: https://www.photopea.com
Squoosh
Free compression tool
Simple interface
Can dramatically reduce file size
Example: An 800 KB image reduced to 11 KB using Squoosh.
Link: https://squoosh.app
Other Editing Apps
Tools like Adobe Photoshop or other image editors can also reduce file size.
Limit Custom HTML
Knak is designed as a no-code campaign creation platform. Custom HTML can increase email size because it adds extra code. Use custom code only when necessary.
Before adding HTML:
Check if the feature exists in the builder.
Contact support to confirm if there is a no-code solution.
Need more help? Contact Support via live chat within Knak using the chat bubble in the bottom right corner or email support@knak.com