diff --git a/src/pages/tools/string/censor/service.ts b/src/pages/tools/string/censor/service.ts
new file mode 100644
index 0000000..660cdcc
--- /dev/null
+++ b/src/pages/tools/string/censor/service.ts
@@ -0,0 +1,49 @@
+import { InitialValuesType } from './types';
+
+export function censorText(input: string, options: InitialValuesType): string {
+  if (!input) return '';
+  if (!options.wordsToCensor) return input;
+
+  if (options.censoredBySymbol && !isSymbol(options.censorSymbol[0])) {
+    throw new Error('Enter a valid censor symbol (non-alphanumeric or emoji)');
+  }
+
+  // Split text into words and punctuation using Unicode-aware regex
+  const regex = /([\s\p{P}])/gu;
+  const textWords = input.split(regex);
+
+  // Normalize censor words (trim and lowercase)
+  const wordsToCensor = options.wordsToCensor
+    .split('\n')
+    .map((word) => word.trim().toLowerCase())
+    .filter((word) => word.length > 0);
+
+  const censoredText = textWords
+    .map((word) => {
+      const lowerWord = word.toLowerCase();
+      if (wordsToCensor.includes(lowerWord)) {
+        if (options.censoredBySymbol) {
+          return options.eachLetter
+            ? options.censorSymbol.repeat(word.length)
+            : options.censorSymbol;
+        } else {
+          return options.censorWord;
+        }
+      }
+      return word;
+    })
+    .join('');
+
+  return censoredText;
+}
+
+/**
+ * Determines if a character is a symbol or emoji.
+ * Accepts single characters that are non-letter and non-number,
+ * or extended pictographic characters (like emojis).
+ */
+function isSymbol(input: string): boolean {
+  return (
+    /^[^\p{L}\p{N}]+$/u.test(input) || /\p{Extended_Pictographic}/u.test(input)
+  );
+}