Custom Fields - Store Any Data, Personalize Everything | SMASHSEND

[

](https://smashsend.com/)

Features

Integrations & API

Resources

1. [

   Home

   ](https://smashsend.com/)

/

3. [

   Custom Fields

   ](https://smashsend.com/custom-fields)

Go beyond basic contact info. With SMASHSEND Custom Fields, track any data that matters to your business — from shoe sizes to subscription tiers, purchase history to preferences.

Unlimited custom fields · All data types supported · API access included

E-commerce fieldsMulti-select

favorite_categories["Electronics", "Fashion"]

lifetime_value$2,450.00

last_purchase_date2024-03-15

preferred_sizeLarge

SaaS propertiesNumber

api_calls_this_month45,291

team_members12

storage_used_gb28.5

feature_adoption_score87%

The most flexible custom fields in email marketing

While others limit you to basic fields, SMASHSEND gives you the power to store any data type, create complex properties, and use them everywhere.

∞

Unlimited fields

10+

Data types

0ms

Real-time sync

Every data type you need

Text & numbers

Store names, descriptions, IDs, scores, prices, quantities, or any text and numeric data. Perfect for basic customer information and metrics.

Lists & arrays

Track multiple values like product interests, tags, categories, or preferences. Use single-select or multi-select options for structured data.

Dates & booleans

Capture timestamps, anniversaries, expiration dates, or yes/no flags. Perfect for time-based automations and conditional logic.

JSON objects

Store complex nested data structures for advanced use cases. Perfect for developers who need maximum flexibility.

Encrypted fields

Store sensitive data securely with field-level encryption. Perfect for PII, tokens, or any confidential information.

Computed fields

Create dynamic fields that calculate values based on other properties. Update automatically as source data changes.

Use custom fields everywhere

Your custom fields aren't locked away — use them across the entire SMASHSEND platform for truly personalized experiences.

In email campaigns

Personalize every email with custom field tokens. Display customer-specific data, recommendations, or dynamic content based on any property.

In segmentation

Build powerful segments using any custom field. Combine multiple conditions with AND/OR logic to target exactly the right audience.

In automations

Trigger workflows based on custom field changes. Update fields automatically, create conditional branches, or sync with external systems.

Via API & webhooks

Full API access to read and write custom fields. Receive webhooks when fields change. Keep your entire stack in sync.

Personalize with field tokens

Reference any property directly in your campaign copy.

Hi {{first_name}},

Based on your preference for {{favorite_category}},
we thought you'd love our new collection!

Your loyalty points: {{loyalty_points}}
Member since: {{member_since}}

Real-world use cases

See how businesses use SMASHSEND Custom Fields to create powerful, data-driven email experiences.

E-commerce

Personalization that uses real history

Track purchase history, browsing behavior, size preferences, and wish list items, then target recommendations off those fields.

Targeted product recommendations convert 3x better.

SaaS

Onboarding driven by adoption

Monitor feature adoption, usage metrics, and subscription details, and trigger onboarding emails from user behavior and progress.

Every onboarding email matches where the user actually is.

Education

Courses that respond to progress

Track course progress, quiz scores, and learning preferences to send content recommendations and achievement celebrations.

Learners get the next step, not the same newsletter.

Healthcare

Compliant, personal reminders

Store appointment history, preferences, and consent data securely with field-level encryption.

HIPAA-compliant reminders and personalized health tips.

Real estate

Match leads to listings

Track property preferences, budget ranges, and viewing history so the right listing reaches the right lead.

Leads matched with properties automatically.

Gaming

Player-aware messaging

Store player stats, achievements, and preferences to drive game updates, rewards, and recommendations.

Updates that reflect how each player actually plays.

SMASHSEND vs. limited field systems

Most email platforms limit you to basic fields. See why developers and marketers choose SMASHSEND for true flexibility.

Feature

SMASHSEND

Others

Number of custom fields

Unlimited

10-50 fields

Data types supported

All types + JSON

Text & numbers only

Array/list support

Native support

Not supported

API access

Full CRUD API

Limited or paid

Field validation

Custom validators

Basic only

Pricing

Included free

Premium add-on

Developer-friendly integration

Built by developers, for developers. Integrate custom fields with your application in minutes, not days.

// Create a custom field
const field = await smashsend.customFields.create({
  name: 'subscription_tier',
  type: 'select',
  options: ['free', 'pro', 'enterprise'],
  defaultValue: 'free'
});

// Update contact with custom field
await smashsend.contacts.update('ctc_abc123', {
  email: 'user@example.com',
  properties: {
    subscription_tier: 'pro',
    last_login: new Date(),
    feature_flags: ['dark_mode', 'beta_access'],
    usage_stats: {
      api_calls: 1523,
      storage_gb: 12.5
    }
  }
});

Part of the complete SMASHSEND platform

Custom fields work seamlessly with every SMASHSEND feature. One platform, infinite possibilities.

Start building with custom fields today

Join thousands of businesses using SMASHSEND Custom Fields to create truly personalized email experiences.

Unlimited fields • All data types • Full API access • Free forever