toLowerCase — GTM Variable Template for String

VARIABLES › STRING

toLowerCase CORE String

Direct (.tpl) Apply (.tpl)

Converts the input value to lowercase string. Returns undefined if the input is not a valid string.

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When to Use This

String Manipulation

Transform, clean, and normalize text data for consistent downstream processing.

Type Conversion

Safely convert between data types — strings, numbers, booleans, arrays, objects.

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Examples

Simple uppercase▶ Try

INPUT

String To Convert: HELLO WORLD

OUTPUT

hello world

Non-string input returns undefined▶ Try

INPUT

String To Convert: 12345

OUTPUT

undefined

Mixed case with special characters▶ Try

INPUT

String To Convert: Product Name: iPhone 15 PRO Max

OUTPUT

product name: iphone 15 pro max

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GTM Configuration

This is what you'll see when you open this variable in Google Tag Manager. Hover the icons for details.

toLowerCase

Read-Only Try Live

String To Convert

💾 The value to be converted to lowercase.

Supported formats:
  ✓ String

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the input before internal logic (e.g., convert object to string, normalize case). Internal transformations such as case handling will still apply afterward.

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result before returning it (e.g., str => str + ' €', val => val !== undefined for boolean conversion). Useful for chaining transformations on the output.

String To Convert string

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

toLowerCase()

+ Chain another variable

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Related Variables

Same category: String

→ assignParamsToString → charAt → concatenateValues → countWordsInString → endsWith → extract → extractFirstSegment → extractNumber → fromBase64 → indexOf → left → matchAll → matchRegex → omitParamsFromString → padEnd → padStart → pickParamsFromString → replaceAll → replaceAllWithRegex → replaceFirst → right → safeSplit → sanitizeTextAndRemoveHtml → sanitizeTextLite → search → slice → split → startsWith → test → toBase64 → toCamelCase → toJsonString → toKebabCase → toLocaleLowerCase → toLocaleUpperCase → toNumber → toSnakeCase → toStartCase → toString → toStringRepresentation → toUpperCase → toUpperFirst → trim → trimEnd → trimStart → truncate

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Under the Hood

📜 View Implementation Code

/**
* Converts the input value to lowercase.
* 
* @param {any} data.src - The value to be converted to lowercase.
* @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
*
* Direct-mode specific parameters:
* @param {Function} [data.pre] - Optional pre-processor function to transform src before conversion.
* 
* @returns {string|undefined} The lowercase string, or undefined if the input is not a valid string.
*
* @framework ggLowCodeGTMKit
*/
const toLowerCase = function(string) {
   return typeof string === 'string' ? string.toLowerCase() : undefined;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// toLowerCase - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(toLowerCase(value));

// ===============================================================================
// toLowerCase() – Apply Mode
// ===============================================================================
/*
return function(value) {
  return out(toLowerCase(value));
};
*/

🧪 View Test Scenarios (6 tests)

✅ '[example] Simple uppercase'
✅ '[example]Non-string input returns undefined'
✅ '[example] Mixed case with special characters'
✅ Mixed case string - should convert to lowercase
✅ Already lowercase string - should remain lowercase
✅ Empty string - should return empty string