All Tools
Categories
Email Marketing Tools 51 Text Tools 12 Marketing Tools 3 Encoder Tools 1 Security Tools 1 Generator Tools 1
About Contact Privacy

Email Merge Tag & Variable Validator

Validate email merge tags and template variables for generic {{variables}}, Mailchimp, HubSpot, Klaviyo, and Salesforce Marketing Cloud syntax. Find malformed tags before sending.

Validation settings

Your content stays in this browser.

Ready to validate merge tagsSelect a platform, then paste your email content to scan its variables.
Important: This is a syntax checker, not a connection to your email platform. After fixing errors, preview with real and incomplete contact data in your ESP before sending.

About Email Merge Tag & Variable Validator

Email Merge Tag & Variable Validator checks dynamic fields in your campaign before they become a visible send error. Choose your email platform syntax, paste your email copy or HTML, and review recognized tags, malformed variables, mismatched delimiters, and unsupported tag formats.

Email service providers use different templating languages. A tag that works in Mailchimp may display as raw text in HubSpot, Klaviyo, or Salesforce Marketing Cloud. This free validator provides a fast structural check, then you can confirm data mapping with your provider’s own preview and test-send tools. All analysis is performed locally in your browser.

Features

  • Platform-aware validation: Select generic curly braces, Mailchimp, HubSpot, Klaviyo, or Salesforce Marketing Cloud syntax.
  • Recognized-tag inventory: See each detected variable, its location, and its syntax status.
  • Malformed delimiter checks: Find opening or closing delimiters that do not match.
  • Mixed-syntax warnings: Spot tags from another platform that may show as raw text.
  • Duplicate variable review: Identify fields used repeatedly in the same email.
  • Private browser processing: Campaign content stays on your device.

How to Use

  1. Select the platform that will send your campaign.
  2. Paste the final email text or HTML, including subject line and preheader if they use variables.
  3. Run validation to view recognized variables, errors, and warnings.
  4. Fix invalid or mixed syntax in the source template.
  5. Use your ESP preview and test send with contacts that have both complete and incomplete profile data.

Examples

Generic / Klaviyo-style example: {{ person.first_name|default:"there" }} uses a variable with a fallback-style filter; confirm the exact format in the sending platform.

Mailchimp example: *|FNAME|* is a common contact merge tag. A missing final asterisk, such as *|FNAME|, should be fixed.

Salesforce Marketing Cloud example: %%FirstName%% is a simple AMPscript personalization string. It will not be interpreted by systems that only support curly-brace variables.

Benefits

  • Reduce send-time mistakes: Catch raw merge tags and broken delimiters before subscribers receive them.
  • Work confidently across ESPs: Avoid accidentally carrying syntax from a previous platform into a new template.
  • Make QA faster: Review all variables in one report instead of scanning long campaign code by hand.
  • Improve personalization reliability: Flag fields that need a platform-specific fallback or data-quality review.
  • Protect draft content: No account or upload is needed to use the validator.

Frequently Asked Questions

What is the difference between a merge tag and a variable?
They are closely related. Both are placeholders replaced with data or dynamic content when an email is sent. “Merge tag” is often used for contact fields such as a first name, while “variable” can also mean template logic, account data, or computed content.
Which email platforms does this validator support?
It can recognize common syntax patterns for generic double-curly-brace variables, Mailchimp merge tags, HubSpot personalization tokens, Klaviyo template variables, and Salesforce Marketing Cloud AMPscript-style variables. Platform versions and custom configurations vary, so always verify with your ESP preview.
Can the tool verify that a field exists in my account?
No. It validates visible syntax and format only; it cannot connect to your ESP or subscriber database. Use your platform’s test recipient preview to verify that every variable maps to real data.
Why are fallback values important?
Contact fields can be blank. A fallback prevents a message such as “Hello ,” or raw code from reaching a recipient. The correct fallback syntax differs by provider, so follow your platform documentation.
What does a malformed merge tag look like?
Common examples include unmatched delimiters, missing closing characters, spaces or unsupported characters in field names, a mistyped delimiter such as *|FNAME|, and mixing the syntax of two ESPs in one template.
Can I mix merge-tag formats in one email?
Usually no. A sending platform typically processes only its own syntax. Mixed formats can leave raw tags visible in the delivered email unless a specific integration converts them before send.
Is pasted email content stored?
No. This validator analyzes pasted text locally in your browser. It does not upload or retain your email content.

Related Tools

Email Personalization Tag Checker

Email Marketing Tools

A/B Test Significance Calculator

Email Marketing Tools

CAN-SPAM Compliance Checklist Generator

Email Marketing Tools

CASL (Canada) Compliance Checker

Email Marketing Tools

Countdown Timer Generator for Email

Email Marketing Tools

Custom Domain Email Setup Checker

Email Marketing Tools