Inside Iterable Personalization: Handlebars, Dynamic Content, & Snippets

For architecting design systems, orchestrating predictive journeys, or managing localization-scale campaigns, understanding Iterable’s Handlebars, dynamic content logic, and snippets is essential—not at the campaign level, but as a modular personalization framework that underpins the entire messaging strategy.

For teams managing thousands of users, Iterable’s personalization framework solves three persistent bottlenecks:

• Reusability bottleneck: Static copy variations across lifecycle journeys tend to become unmaintainable without snippets and templating functions.
  
• Logic fragmentation: Tossing personalization logic into journeys, campaigns, and email templates separately leads to duplication and versioning chaos.
  
• Dynamic dependency sprawl: Without structured data flow and Handlebars, conditional rendering for multi-segment campaigns devolves into code entropy.

If that sounds familiar, you’re in the right place! 

We take a deep dive into Iterable’s personalization system, exploring the Handlebars templating engine, dynamic content features, and snippets for dynamic email personalization. 

How to Use Iterable Handlebars for Personalization

Personalization lies at the heart of effective email marketing, and Iterable’s Handlebars makes it possible to deliver dynamic, highly relevant experiences at scale. By merging user profile and event data directly into templates at send time, Handlebars expressions enable you to tailor every message to individual recipients.  

In this section, we’ll explore how Handlebars works, its core concepts, and advanced techniques to maximize personalization potential while maintaining clean, reliable template code. This is key to building personalized email campaigns in Iterable that scale across lifecycle stages.

Iterable: Personalization Core Concepts

Before diving into complex personalization logic, it’s essential to understand the fundamentals of how Handlebars expressions function in Iterable. 

These concepts form the foundation for all Iterable personalization features.

1. Merge Parameters
   To insert dynamic data, wrap any user profile or event field in double curly braces. For example, {{firstName}} or {{email}}.
   
2. Data Precedence
   If both event data and user profile data contain the same field name, the event data takes precedence. 
   However, you can explicitly reference profile fields using {{profile.fieldName}} to avoid confusion.
   
3. Special Field Names
   When fields contain spaces, periods, or start with numbers, wrap them in square brackets. Examples include {{[First Name]}} or {{[1stName]}}.
   
   These core rules define how Handlebars interacts with your data sources. 
   
   Mastering them ensures your personalization logic behaves predictably and avoids common data conflicts or rendering errors when using Handlebars in Iterable.
   

Key Techniques for Personalization in Iterable

Once you’re comfortable with the basics, you can apply Handlebars helpers and logic to make your emails dynamic, contextual, and human-sounding. The following techniques highlight how to manipulate strings, control logic, and loop through data effectively.

String Manipulation

Text customization is often the first step in customizing email templates in Iterable.

• Capitalization: Use {{capitalizeFirst firstName}} or {{capitalize “product name”}} to ensure consistent styling.
  
• Default Values: With {{defaultIfEmpty customGreeting “Hello there”}}, you can provide fallback text if data is missing.
  
• String Replacement: Convert spaces into hyphens for URLs using {{replace productName ” ” “-“}}.

These string-based transformations ensure that your templates remain clean and readable, even when user data varies in format or completeness.

Conditional Logic

Iterable Handlebars allows for conditional rendering, showing or hiding content depending on user attributes or behavior.

Example:

{{#if activeUser}}
    Welcome back! Here are your recommendations.
{{else}}
    We miss you! Come check out what's new.
{{/if}}

You can also combine conditions using logical helpers such as #and and #or:

{{#and (gte purchaseCount 5) (eq loyaltyTier "gold")}}
    Exclusive offer for our VIP customers!
{{/and}}

Conditional logic is crucial for adaptive messaging—helping you show the right content to the right user at the right time.

Dynamic Content with Arrays

When working with lists, such as cart items or recommendations, Handlebars’ looping capabilities simplify data presentation. Example:

{{#each shoppingCartItems}}
    Item {{math @index '+' 1}}: {{name}} - ${{price}}
{{/each}}

Loops make it easy to scale dynamic email templates in Iterable for multi-item data structures without repetitive markup.

Date Personalization
Time-sensitive content benefits greatly from Handlebars’ date utilities.

• Formatting Dates:

{{dateFormat eventDate format=”EEEE, MMMM dd” tz=”America/New_York”}}

• Relative Dates:

{{dateMath “now” “+7d” format=”long”}}

Date personalization keeps your messaging timely, localized, and relevant across user time zones and event triggers.

Numeric Formatting

To present prices, quantities, or discounts neatly, Handlebars offers numeric formatting helpers:

{{numberFormat totalPrice “currency” “en_US”}}

{{numberFormat discount “percent”}}

This ensures financial data and metrics appear consistent and professional across every send.

Advanced Personalization in Iterable

For developers and marketers seeking deeper control, advanced Handlebars functions extend personalization to decision-making, variable storage, and HTML rendering.

• Send Abortion: Prevent sending messages when conditions aren’t met:

{{#ifLt creditAvailable product.price}}

  {{sendSkip cause=”insufficient credit”}}

{{/ifLt}}

• Variable Assignment: Reuse computed values within the same template:

{{#assign “discountedPrice”}}{{math originalPrice ‘*’ 0.8}}{{/assign}}

Save {{math originalPrice ‘-‘ discountedPrice}}!

• HTML Content: Render rich text safely using triple braces:

{{{customHTMLcontent}}}

These advanced patterns enable smarter templates that react intelligently to user data, offering a higher level of automation and precision that defines Iterable email customization.

Critical Best Practices for Using Handlebars in Iterable

Maintaining reliability in Handlebars-driven emails requires disciplined coding and awareness of Iterable’s quirks:

• Comment Non-Output Expressions: Wrap conditionals in HTML comments to prevent WYSIWYG conflicts: <!–{{#if condition}}–>.
  
• Whitespace Control: Use tildes to remove unwanted spaces, especially in URLs and deep links.
  
• Field Name Sensitivity: Field names are case-sensitive ({{Email}} ≠ {{email}}).
  
• Null Handling: Always define defaults or conditionals to avoid empty or broken content.

Adhering to these best practices ensures that your email templates remain robust, editable, and predictable—even as your personalization logic becomes sophisticated.

Inside Iterable Dynamic Content

Dynamic email personalization doesn’t always require writing code!

Iterable’s Dynamic Content Builder gives marketers the ability to craft customized experiences for each recipient using a simple, visual interface.

Instead of manually scripting Handlebars expressions, Dynamic Content Builder lets you define logic, set fallback options, and preview personalized versions—all within a few clicks. Whether you’re displaying different images to distinct audience segments or inserting tailored text blocks, this is one of the most effective Iterable personalization features. 

How to Create A Dynamic Content Block 

You can create dynamic content blocks across multiple message types—Email, SMS, Push, In-App, and Web App templates or snippets. 

To get started, open your desired template and either click the Dynamic Content button or drag a Dynamic Content tile directly into your layout. This action opens the Dynamic Content Builder menu, where you’ll define how each variation of your message should appear and who should see it.

Defining Content Block Criteria 

You’ll begin with an if statement. 

This specifies what content to show to users who meet a particular set of criteria. Next, you’ll add else if statements that define alternative content for other audience segments.

Setting Up an If Statement

When configuring your first rule, choose whether your condition will be based on a user property or an event. Then select a comparator and define your target value.

If you’re using an event as your condition, note that it must be the same event that triggered the message send.

To further refine your audience, use AND or OR statements:

• Use AND to send content only to users who meet all selected conditions.
  
• Use OR to target anyone who meets any one condition. 

You can add up to four AND/OR clauses in each statement.

Once your audience rules are defined, choose the type of content you want to display:

• Image (up to 20 MB, max 1920 px)
  
• Text (plain or formatted)
  
• Snippet

Keep in mind that not all channels support all content types. For example, SMS templates don’t support images.

Setting Up Else If Statements

Once your main if statement is defined, click Add Variant to create your first else if statement. This allows you to set up secondary audience rules and associated content for users who don’t meet the initial criteria.

Now, you can repeat this process for multiple audience segments, up to a maximum of one if statement and five else if statements per dynamic content block.

Adding Fallback Content

Some recipients may not match any of your defined conditions. To prevent empty content blocks or layout gaps, add fallback content as a final safety net. This ensures everyone receives a complete, consistent experience, even if they don’t fit into any segment.

Inserting the Dynamic Content Block 

Once your dynamic variants are configured, click Insert Handlebars. 

Iterable will automatically generate the corresponding Handlebars code for your setup and place it directly into your template or snippet. From here, simply save your template and proceed to test or schedule your campaign.

This workflow is invaluable when customizing email templates in Iterable for segmentation and localization needs.

Leveraging Snippets in Iterable 

Snippets in Iterable are reusable content blocks that make building and personalizing messages faster and more efficient. With snippets, marketers can manage frequently used elements such as email headers and footers, store complex logic blocks, and update multiple templates simultaneously.

Understanding Snippets

Each snippet consists of a few key components:

• Name: Assign a descriptive and consistent name to your snippet. Snippet names can include letters, numbers, spaces, dashes, and underscores, but once saved, they cannot be changed. These names are internal and used only within your organization.
  
• Snippet Content: This is the actual content inserted into templates referencing the snippet. It may include HTML (with hosted images), inline CSS (using the style attribute), and Handlebars logic. Snippets follow standard CSS precedence rules and can reference data feeds when configured properly. However, snippets cannot include <script>, <iframe>, JavaScript, or references to themselves.
  
• Variables: Variables allow snippets to be customized across templates. Templates referencing a snippet must provide values for these variables—such as CTAs, colors, or conditions for dynamic logic.
  
• Snippet Expression: Iterable generates Handlebars expressions that act as shortcuts to include snippets in templates.

Creating a Snippet

Snippets are managed under Content > Snippets, where all reusable content blocks are stored.
To create a new snippet:

1. Navigate to Content > Snippets and click New Snippet.
2. Add a unique, descriptive name (unchangeable after saving).
3. Optionally, define variables and a short description for clarity.
4. Enter your snippet content in the Editor section. You can work in either the WYSIWYG or Side-by-Side Editor (adjustable in Settings > Project Settings).
5. Click Save Snippet.

Editing Snippets

Be cautious when editing snippets—any saved change instantly impacts all templates referencing that snippet. The safest approach is to save a copy before making changes:

1. Navigate to Content > Snippets.
   
2. Open the existing snippet and make necessary edits.
   
3. In the Save Snippet menu, click Save as New, name the copy, and save it.
   
4. Test the new snippet in a template, preview with data, and send proofs.
   
5. Once verified, replace the original snippet’s content to update globally.

Snippet Editors

Iterable offers two editing modes: WYSIWYG and Side-by-Side.

• Snippets containing HTML default to the WYSIWYG editor.
  
• Plain-text snippets open in the Side-by-Side editor.
  
• Switching between editors is allowed, but note that WYSIWYG may add unwanted HTML tags. To verify or clean up markup, use the Side-by-Side view.

Adding a Snippet to a Template

To insert a snippet, paste its snippet expression into any field that accepts Handlebars, for example:

{{{ snippet “Your_Snippet_Name” “variable1” “variable2” }}}

You can copy snippet expressions directly from the Snippets page or use the Insert Snippet button in the template editor.

If the snippet includes HTML, ensure it’s placed only in fields that support HTML, such as the message body. For HTML rendering, use triple curly braces, and for text-only rendering, use double curly braces. 

Working with Variables

If a snippet has variables, provide appropriate values within the expression. For example:

• String: {{{ snippet “mySnippet” “Fall Sale” }}}
  
• Number: {{{ snippet “mySnippet” 3.14 }}}
  
• Boolean: {{{ snippet “mySnippet” true }}}
  
• User field: {{{ snippet “mySnippet” favoriteColor }}}

Always pass values that make sense and follow the defined variable order. Missing values may lead to unexpected outputs.

Testing and Styling Snippets

After adding snippets to templates:

• Use Preview with Data to check for different user profiles.
  
• Send proofs to test users.
  
• If styles appear off, adjust snippet styling in the template editor or, if needed, in the snippet definition itself.

Be cautious when editing snippet-level styles. Changes will affect every email template using that snippet.

Best Practices for Snippets in Iterable 

While snippets can greatly streamline content management in Iterable, using them effectively requires care and consistency. These best practices help ensure snippets stay efficient, stable, and easy to maintain across campaigns:

• Utilize snippets for text, HTML (with hosted images), inline CSS, Handlebars, and data feeds. Always close tags and test rendering.
  
• You can copy snippets across projects. Ensure unique names and copy nested snippets separately—they’re not included automatically.
  
• Use snippets only in HTML-supported fields.
  
• Nested snippets are supported, but risky. Deep nesting slows rendering and may cause skips. Never reference a snippet within itself.
  
• You can include Catalogs and Collections, though large datasets can slow rendering. Test thoroughly before launch.
  
• Add personalization with Handlebars, but keep logic simple. Always test with real data and set fallbacks for missing profile fields.
  
• Remove snippets from all templates before deleting. Deleted snippets can’t be recovered, so back up first.
  
• Avoid global style edits—they affect all templates. Override styles within template editors and test with Preview with Data before sending.

Iterable Personalization: Closing Thoughts 

Handlebars empowers context-aware logic; dynamic content drives adaptive storytelling; snippets institutionalize modular reusability. Together, they form the personalization backbone for marketers operating at lifecycle and enterprise scale.

Iterable’s mastery lies in combining flexibility (via Handlebars) with governance (via snippets). For those creating personalized email campaigns in Iterable, this synergy defines scalability. 

Ready to transform your customer messaging into a seamless, personalized experience? Let our team help you implement and optimize Iterable personalization for maximum impact.

Susmit Panda - Content writer

A realist at heart and an idealist at head, Susmit is a content writer at Email Mavlers. He has been in the digital marketing industry for half a decade. When not writing, he can be seen squinting at his Kindle, awestruck.