diff --git a/AGENT.md b/AGENT.md
index 050689a..fca7945 100644
--- a/AGENT.md
+++ b/AGENT.md
@@ -30,7 +30,12 @@ This repository contains `arabic-services`: a zero-runtime-dependency TypeScript
   - `tashkeel.ts`: Diacritics (Harakat, Tanween, Quranic sequential tanween).
   - `banned-words.ts`: Word lists used in obfuscation/tashfeer algorithms.
 - `src/scripts/`:
-  - `scripts.ts`: Implementation of text manipulation functions (Tashkeel removal, Tatweel removal, Tashfeer, Old Arabic conversion, Affixes removal, etc.).
+  - `tashkeel.ts`: Tashkeel and Tatweel removal (`removeTashkeel`, `removeTatweel`).
+  - `old-arabic.ts`: Dotless Old Arabic script transformation (`toOldArabic`).
+  - `tashfeer.ts`: Visual obfuscation and banned-word encoding (`tashfeer`, `tashfeerBannedWords`, `toOldArabicAndTashfeerBannedWords`).
+  - `affixes.ts`: Prefix and suffix stripping heuristic (`removeArabicAffixes`).
+  - `letters.ts`: Conversion of words to pronounced letter names (`wordToLetters`).
+  - `index.ts`: Barrel file re-exporting all script operations.
 - `src/utils/`:
   - `string.util.ts`: Internal string manipulation and regex utility functions.
 - `tests/`:
@@ -50,7 +55,7 @@ This repository contains `arabic-services`: a zero-runtime-dependency TypeScript
 - **Unicode Code Point Integrity**: Arabic characters have unique Unicode points for letters, ligatures, Tatweel (`\u0640`), Tashkeel (`\u064B`-`\u0652`, `\u0670`, sequential tanween, etc.). Avoid naive character splitting that breaks multi-byte or combining marks; always respect Unicode boundaries.
 - **Regular Expressions & ReDoS**: Regular expressions must be tested against catastrophic backtracking (ReDoS). Prefer pre-compiled regexes or Set/Dictionary lookups for character replacement rather than dynamic nested patterns.
 - **Dual Runtime Support**: The core library runs in both Node.js and web browsers. Never import Node-specific built-ins (`fs`, `path`, `crypto`, `os`) inside `src/`.
-- **Test-Driven Changes**: Every bug fix, edge case, or new feature in `src/scripts/scripts.ts` must be accompanied by unit tests in `tests/scripts.test.ts`.
+- **Test-Driven Changes**: Every bug fix, edge case, or new feature in `src/scripts/` must be accompanied by unit tests in `tests/scripts.test.ts` or `tests/edge-cases.test.ts`.
 
 ---
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d717f85..99266ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 - Direct CDN links (jsdelivr & unpkg) and GitHub release bundle guide in documentation.
 
 ### Changed
+- Modularized monolithic `src/scripts/scripts.ts` into focused single-responsibility files (`tashkeel.ts`, `old-arabic.ts`, `tashfeer.ts`, `affixes.ts`, `letters.ts`) while keeping public exports and backward compatibility completely unchanged.
 - Relocated standalone browser demo to `examples/browser/index.html`.
 - Unified CI workflow across Node.js 22.x and 24.x with ESLint.
 
diff --git a/src/scripts/affixes.ts b/src/scripts/affixes.ts
new file mode 100644
index 0000000..0e729ab
--- /dev/null
+++ b/src/scripts/affixes.ts
@@ -0,0 +1,47 @@
+import { ARABIC_PREFIXES, ARABIC_SUFFIXES } from '../constants/index.js';
+import { setCharAt } from '../utils/index.js';
+
+/**
+ * Removes predefined affixes (prefixes and suffixes) from an Arabic word if it starts or ends with those affixes.
+ * This function is designed specifically for processing Arabic text, where certain affixes might need to be removed
+ * for linguistic, stylistic, or morphological reasons.
+ *
+ * @param {string} word - The Arabic word from which the affixes are to be removed.
+ * @returns {string} The word after removing any matching affixes. Returns the original word trimmed if no affix matches are found.
+ */
+function removeArabicAffixesFromWord(word: string): string {
+	word = word.trim();
+	if (ARABIC_PREFIXES.includes(word.substring(0, 2))) {
+		// For: ALEF & LAM
+		word = setCharAt(word, 0, '');
+		word = setCharAt(word, 0, '');
+	} else if (ARABIC_PREFIXES.includes(word.substring(0, 1))) {
+		word = setCharAt(word, 0, '');
+	}
+
+	if (ARABIC_SUFFIXES.includes(word.substring(word.length - 2))) {
+		word = setCharAt(word, word.length - 1, '');
+		word = setCharAt(word, word.length - 1, '');
+	} else if (ARABIC_SUFFIXES.includes(word[word.length - 1])) {
+		word = setCharAt(word, word.length - 1, '');
+	}
+
+	return word;
+}
+
+/**
+ * Removes predefined affixes (prefixes and suffixes) from an Arabic text if words start or end with those affixes.
+ * This function is designed specifically for processing Arabic text, where certain affixes might need to be removed
+ * for linguistic, stylistic, or morphological reasons.
+ *
+ * @param {string} text - The Arabic text from which the affixes are to be removed.
+ * @returns {string} The text after removing any matching affixes from each word. Returns the original text trimmed if no affix matches are found.
+ */
+export function removeArabicAffixes(text: string): string {
+	let new_sentence = '';
+	text = text.trim();
+	for (const word of text.split(' ')) {
+		new_sentence += removeArabicAffixesFromWord(word) + ' ';
+	}
+	return new_sentence.trim();
+}
diff --git a/src/scripts/index.ts b/src/scripts/index.ts
index bb1a05c..cd68b17 100644
--- a/src/scripts/index.ts
+++ b/src/scripts/index.ts
@@ -1 +1,5 @@
-export * from './scripts.js';
+export * from './affixes.js';
+export * from './letters.js';
+export * from './old-arabic.js';
+export * from './tashfeer.js';
+export * from './tashkeel.js';
diff --git a/src/scripts/letters.ts b/src/scripts/letters.ts
new file mode 100644
index 0000000..2b90c20
--- /dev/null
+++ b/src/scripts/letters.ts
@@ -0,0 +1,31 @@
+import { PRONOUNCED_LETTERS } from '../constants/index.js';
+
+/**
+ * Converts a word to its pronounced letter representations based on PRONOUNCED_LETTERS.
+ * @param {string} word - The word to convert.
+ * @returns {string} The word with pronounced letters separated by spaces.
+ */
+export function wordToLetters(word: string): string {
+	const trimmedWord = word.trim();
+	let newWord = '';
+
+	// Loop through each character in the input word
+	for (let i = 0; i < trimmedWord.length; i++) {
+		const letter = trimmedWord[i];
+
+		// Check if the current letter has a pronunciation in PRONOUNCED_LETTERS
+		if (PRONOUNCED_LETTERS.hasOwnProperty(letter)) {
+			newWord += PRONOUNCED_LETTERS[letter];
+
+			// Add a space after the pronounced letter unless it's the last letter in the word
+			if (i !== trimmedWord.length - 1) {
+				newWord += ' ';
+			}
+		} else {
+			// If the letter is not in PRONOUNCED_LETTERS, keep it unchanged
+			newWord += letter;
+		}
+	}
+
+	return newWord.trim();
+}
diff --git a/src/scripts/old-arabic.ts b/src/scripts/old-arabic.ts
new file mode 100644
index 0000000..dd205ad
--- /dev/null
+++ b/src/scripts/old-arabic.ts
@@ -0,0 +1,50 @@
+import { ARABIC_DOTLESS_DICT } from '../constants/index.js';
+import { fillDefaultOptions, OldArabicOptions } from '../options.js';
+import { removeTashkeel } from './tashkeel.js';
+
+/**
+ * Remove all dots & tashkeel from text
+ * @param sentence string to convert to old arabic
+ * @param option
+ * @returns string in old arabic
+ * @example
+ *   Input: "الخَيْلُ وَاللّيْلُ وَالبَيْداءُ تَعرِفُني"
+ *   Output: "الحىل واللىل والٮىدا ٮعرڡٮى"
+ */
+export function toOldArabic(sentence: string, option: OldArabicOptions = {}): string {
+	const { replaceMidNoonWithBah, replaceMidYahWithBah } = fillDefaultOptions(option);
+	sentence = removeTashkeel(sentence.trim());
+	let newSentence = '';
+	for (let letter = 0; letter < sentence.length; letter++) {
+		// if letter is not Arabic letter => append to newSentence
+		if (!ARABIC_DOTLESS_DICT.hasOwnProperty(sentence[letter])) {
+			newSentence += sentence[letter];
+		}
+		// Handle 'ن' Issue:
+		// if 'ن' is not last character && next character is Arabic letter or 'ـ'
+		// then replace it with 'ب' corresponding dotless letter => 'ٮ'
+		else if (
+			replaceMidNoonWithBah &&
+			sentence[letter] == 'ن' &&
+			letter + 1 < sentence.length &&
+			(ARABIC_DOTLESS_DICT.hasOwnProperty(sentence[letter + 1]) || sentence[letter + 1] == 'ـ')
+		) {
+			newSentence += ARABIC_DOTLESS_DICT['ب'];
+		}
+		// Handle 'ي' Issue
+		// if 'ي' is not last character && next character is Arabic letter or 'ـ'
+		// then replace it with 'ب' corresponding dotless letter => 'ٮ'
+		else if (
+			replaceMidYahWithBah &&
+			sentence[letter] == 'ي' &&
+			letter + 1 < sentence.length &&
+			(ARABIC_DOTLESS_DICT.hasOwnProperty(sentence[letter + 1]) || sentence[letter + 1] == 'ـ')
+		) {
+			newSentence += ARABIC_DOTLESS_DICT['ب'];
+		} else {
+			// if letter is Arabic letter => append corresponding dotless letter to newSentence
+			newSentence += ARABIC_DOTLESS_DICT[sentence[letter]];
+		}
+	}
+	return newSentence;
+}
diff --git a/src/scripts/scripts.ts b/src/scripts/tashfeer.ts
similarity index 58%
rename from src/scripts/scripts.ts
rename to src/scripts/tashfeer.ts
index a466041..5c5477b 100644
--- a/src/scripts/scripts.ts
+++ b/src/scripts/tashfeer.ts
@@ -1,180 +1,15 @@
-import { ARABIC_DOTLESS_DICT, BANNED_WORDS, TASHKEEL } from '../constants/index.js';
+import { BANNED_WORDS } from '../constants/index.js';
 import {
 	ALEF,
 	ALONE_LETTERS,
-	ARABIC_PREFIXES,
-	ARABIC_SUFFIXES,
 	LETTERS_TASHFEER_REPLACEMENT_DICT,
-	PRONOUNCED_LETTERS,
 	STANDARD_LETTERS,
 	WAW,
 	YAA,
 } from '../constants/arabic-letters.js';
-import { fillDefaultOptions, type OldArabicOptions } from '../options.js';
-import { setCharAt, similarityScore } from '../utils/index.js';
-
-/**
- * Remove all tashkeel from text
- * @param text string to remove tashkeel from
- * @returns string without tashkeel
- * @example
- *   Input: "الخَيْلُ وَاللّيْلُ وَالبَيْداءُ تَعرِفُني"
- *   Output: "الخيل والليل والبيداء تعرفني"
- */
-export function removeTashkeel(text: string): string {
-	return text
-		.trim()
-		.replace(new RegExp('[' + TASHKEEL.join('') + ']', 'g'), '')
-		.replace(/ٱ/g, 'ا');
-}
-
-/**
- * Remove all dots & tashkeel from text
- * @param sentence string to convert to old arabic
- * @param option
- * @returns string in old arabic
- * @example
- *   Input: "الخَيْلُ وَاللّيْلُ وَالبَيْداءُ تَعرِفُني"
- *   Output: "الحىل واللىل والٮىدا ٮعرڡٮى"
- */
-export function toOldArabic(sentence: string, option: OldArabicOptions = {}): string {
-	const { replaceMidNoonWithBah, replaceMidYahWithBah } = fillDefaultOptions(option);
-	sentence = removeTashkeel(sentence.trim());
-	let newSentence = '';
-	for (let letter = 0; letter < sentence.length; letter++) {
-		// if letter is not Arabic letter => append to newSentence
-		if (!ARABIC_DOTLESS_DICT.hasOwnProperty(sentence[letter])) {
-			newSentence += sentence[letter];
-		}
-		// Handle 'ن' Issue:
-		// if 'ن' is not last character && next character is Arabic letter or 'ـ'
-		// then replace it with 'ب' corresponding dotless letter => 'ٮ'
-		else if (
-			replaceMidNoonWithBah &&
-			sentence[letter] == 'ن' &&
-			letter + 1 < sentence.length &&
-			(ARABIC_DOTLESS_DICT.hasOwnProperty(sentence[letter + 1]) || sentence[letter + 1] == 'ـ')
-		) {
-			newSentence += ARABIC_DOTLESS_DICT['ب'];
-		}
-		// Handle 'ي' Issue
-		// if 'ي' is not last character && next character is Arabic letter or 'ـ'
-		// then replace it with 'ب' corresponding dotless letter => 'ٮ'
-		else if (
-			replaceMidYahWithBah &&
-			sentence[letter] == 'ي' &&
-			letter + 1 < sentence.length &&
-			(ARABIC_DOTLESS_DICT.hasOwnProperty(sentence[letter + 1]) || sentence[letter + 1] == 'ـ')
-		) {
-			newSentence += ARABIC_DOTLESS_DICT['ب'];
-		} else {
-			// if letter is Arabic letter => append corresponding dotless letter to newSentence
-			newSentence += ARABIC_DOTLESS_DICT[sentence[letter]];
-		}
-	}
-	return newSentence;
-}
-
-export function toOldArabicAndTashfeerBannedWords(sentence: string, levelOfTashfeer: number = 2): string {
-	validateTashfeerLevel(levelOfTashfeer);
-	let new_sentence = '';
-	const words = sentence.trim().split(' ');
-	for (const word of words) {
-		if (checkIfBannedWord(word)) {
-			new_sentence += tashfeerHandler(word, levelOfTashfeer) + ' ';
-		} else {
-			new_sentence += toOldArabic(word) + ' ';
-		}
-	}
-	return new_sentence.trim();
-}
-
-/**
- * Remove all tatweel from text
- * @param text string to remove tatweel from
- * @returns string without tatweel
- * @example
- *   Input: "رائـــــــع"
- *   Output: "رائع"
- */
-export function removeTatweel(text: string): string {
-	return text.trim().replace(/ـ/g, '');
-}
-
-/**
- * Converts a word to its pronounced letter representations based on PRONOUNCED_LETTERS.
- * @param {string} word - The word to convert.
- * @returns {string} The word with pronounced letters separated by spaces.
- */
-export function wordToLetters(word: string): string {
-	const trimmedWord = word.trim();
-	let newWord = '';
-
-	// Loop through each character in the input word
-	for (let i = 0; i < trimmedWord.length; i++) {
-		const letter = trimmedWord[i];
-
-		// Check if the current letter has a pronunciation in PRONOUNCED_LETTERS
-		if (PRONOUNCED_LETTERS.hasOwnProperty(letter)) {
-			newWord += PRONOUNCED_LETTERS[letter];
-
-			// Add a space after the pronounced letter unless it's the last letter in the word
-			if (i !== trimmedWord.length - 1) {
-				newWord += ' ';
-			}
-		} else {
-			// If the letter is not in PRONOUNCED_LETTERS, keep it unchanged
-			newWord += letter;
-		}
-	}
-
-	return newWord.trim();
-}
-
-/**
- * Removes predefined affixes (prefixes and suffixes) from an Arabic word if it starts or ends with those affixes.
- * This function is designed specifically for processing Arabic text, where certain affixes might need to be removed
- * for linguistic, stylistic, or morphological reasons.
- *
- * @param {string} word - The Arabic word from which the affixes are to be removed.
- * @returns {string} The word after removing any matching affixes. Returns the original word trimmed if no affix matches are found.
- */
-function removeArabicAffixesFromWord(word: string): string {
-	word = word.trim();
-	if (ARABIC_PREFIXES.includes(word.substring(0, 2))) {
-		// For: ALEF & LAM
-		word = setCharAt(word, 0, '');
-		word = setCharAt(word, 0, '');
-	} else if (ARABIC_PREFIXES.includes(word.substring(0, 1))) {
-		word = setCharAt(word, 0, '');
-	}
-
-	if (ARABIC_SUFFIXES.includes(word.substring(word.length - 2))) {
-		word = setCharAt(word, word.length - 1, '');
-		word = setCharAt(word, word.length - 1, '');
-	} else if (ARABIC_SUFFIXES.includes(word[word.length - 1])) {
-		word = setCharAt(word, word.length - 1, '');
-	}
-
-	return word;
-}
-
-/**
- * Removes predefined affixes (prefixes and suffixes) from an Arabic text if words start or end with those affixes.
- * This function is designed specifically for processing Arabic text, where certain affixes might need to be removed
- * for linguistic, stylistic, or morphological reasons.
- *
- * @param {string} text - The Arabic text from which the affixes are to be removed.
- * @returns {string} The text after removing any matching affixes from each word. Returns the original text trimmed if no affix matches are found.
- */
-export function removeArabicAffixes(text: string): string {
-	let new_sentence = '';
-	text = text.trim();
-	for (const word of text.split(' ')) {
-		new_sentence += removeArabicAffixesFromWord(word) + ' ';
-	}
-	return new_sentence.trim();
-}
+import { similarityScore } from '../utils/index.js';
+import { removeArabicAffixes } from './affixes.js';
+import { toOldArabic } from './old-arabic.js';
 
 /**
  * Validates the encryption level to guarantee bounded execution and prevent infinite loops.
@@ -319,6 +154,7 @@ function tashfeerHandler(word: string, level: number = 0): string {
 /**
  * Performs tashfeer encryption on a given sentence.
  * @param {string} sentence - The input sentence to be encrypted.
+ * @param {number} [levelOfTashfeer=1] - The encryption level.
  * @returns {string} The encrypted sentence.
  */
 export function tashfeer(sentence: string, levelOfTashfeer: number = 1): string {
@@ -380,3 +216,23 @@ export function tashfeerBannedWords(sentence: string, levelOfTashfeer: number =
 	}
 	return new_sentence.trim();
 }
+
+/**
+ * Converts a sentence to old Arabic script and applies tashfeer to banned words.
+ * @param {string} sentence - The input sentence.
+ * @param {number} [levelOfTashfeer=2] - The encryption level (default is 2).
+ * @returns {string} The processed sentence.
+ */
+export function toOldArabicAndTashfeerBannedWords(sentence: string, levelOfTashfeer: number = 2): string {
+	validateTashfeerLevel(levelOfTashfeer);
+	let new_sentence = '';
+	const words = sentence.trim().split(' ');
+	for (const word of words) {
+		if (checkIfBannedWord(word)) {
+			new_sentence += tashfeerHandler(word, levelOfTashfeer) + ' ';
+		} else {
+			new_sentence += toOldArabic(word) + ' ';
+		}
+	}
+	return new_sentence.trim();
+}
diff --git a/src/scripts/tashkeel.ts b/src/scripts/tashkeel.ts
new file mode 100644
index 0000000..350d6be
--- /dev/null
+++ b/src/scripts/tashkeel.ts
@@ -0,0 +1,30 @@
+import { TASHKEEL } from '../constants/index.js';
+
+/**
+ * Remove all tashkeel from text
+ * @param text string to remove tashkeel from
+ * @returns string without tashkeel
+ * @example
+ * ```js
+ * removeTashkeel('الخَيْـلُ وَاللّيْـلُ وَالبَيْـداءُ تَعرِفُني'); // 'الخيـل والليـل والبيـداء تعرفني'
+ * ```
+ */
+export function removeTashkeel(text: string): string {
+	let cleanText = text.trim();
+	cleanText = cleanText.replace(new RegExp(`[${TASHKEEL.join('')}]`, 'g'), '');
+	cleanText = cleanText.replace(/ٱ/g, 'ا');
+	return cleanText;
+}
+
+/**
+ * Remove all tatweel from text
+ * @param text string to remove tatweel from
+ * @returns string without tatweel
+ * @example
+ * ```js
+ * removeTatweel('الخَيْـــلُ'); // 'الخَيْلُ'
+ * ```
+ */
+export function removeTatweel(text: string): string {
+	return text.trim().replace(/\u0640/g, '');
+}
diff --git a/tsconfig.json b/tsconfig.json
index 2b25b0d..b51edc7 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,7 @@
 {
 	"compilerOptions": {
 		"target": "es5",
+		"lib": ["ES2020", "DOM"],
 		"module": "CommonJS",
 		"strict": true,
 		"declaration": true,