diff --git a/client/i18n/locales/english/intro.json b/client/i18n/locales/english/intro.json
index ef8dc8b3ec6..ca1a232ce04 100644
--- a/client/i18n/locales/english/intro.json
+++ b/client/i18n/locales/english/intro.json
@@ -4934,6 +4934,13 @@
           "In this lab, you will build a function that finds the missing letter in a given range of consecutive letters and returns it."
         ]
       },
+      "lab-proofreading-tool": {
+        "title": "Build a Proofreading Tool",
+        "intro": [
+          "In this lab, you will build a proofreading tool that analyzes arrays of words for palindromes and repeated phrases.",
+          "You will practice for loops and nested loops to check palindromes and find repeated word sequences."
+        ]
+      },
       "review-javascript-loops": {
         "title": "JavaScript Loops Review",
         "intro": [
diff --git a/curriculum/challenges/english/blocks/lab-proofreading-tool/69dd63d1dcdeccb7b39ba4c3.md b/curriculum/challenges/english/blocks/lab-proofreading-tool/69dd63d1dcdeccb7b39ba4c3.md
new file mode 100644
index 00000000000..3265bec2c53
--- /dev/null
+++ b/curriculum/challenges/english/blocks/lab-proofreading-tool/69dd63d1dcdeccb7b39ba4c3.md
@@ -0,0 +1,207 @@
+---
+id: 69dd63d1dcdeccb7b39ba4c3
+title: Build a Proofreading Tool
+challengeType: 26
+dashedName: build-a-proofreading-tool
+---
+
+# --description--
+
+In this lab, you will build a proofreading tool that analyzes arrays of words for palindromes and repeated phrases.
+
+A palindrome is a word that reads the same forwards and backwards. For example, `"racecar"` and `"level"` are palindromes, but `"hello"` is not.
+
+A phrase is a sequence of consecutive words. For example, in `["the", "cat", "sat", "the", "cat"]`, the phrase `"the cat"` (a sequence of 2 words) appears at positions 0 and 3.
+
+**Objective:** Fulfill the user stories below and get all the tests to pass to complete the lab.
+
+**User Stories:**
+
+1. You should define a function named `isPalindrome` that takes a `word` string as its argument. It should return `true` if the word reads the same forwards and backwards (case-insensitive), and `false` otherwise.
+
+2. You should define a function named `findPalindromeBreaks` that takes a `words` array as its argument. It should return an array of indices of words that are not palindromes. It should return an empty array if the input is empty.
+
+3. You should define a function named `findRepeatedPhrases` that takes a `words` array and a `phraseLength` number as arguments. It should return an array of all start indices where a sequence of `phraseLength` consecutive words appears more than once in the array — including the index of the first occurrence. It should return an empty array if `phraseLength` is greater than or equal to the length of `words`.
+
+4. You should define a function named `analyzeTexts` that takes a `texts` array and a `phraseLength` number as arguments. It should process each element of `texts` (each an array of words) and return an array of objects, each with `repeatedPhrases` and `palindromeBreaks` properties. It should return an empty array if `texts` is empty.
+
+# --hints--
+
+`isPalindrome` should be a function.
+
+```js
+assert.isFunction(isPalindrome);
+```
+
+`isPalindrome` should return `true` for a palindrome.
+
+```js
+assert.isTrue(isPalindrome("racecar"));
+assert.isTrue(isPalindrome("a"));
+```
+
+`isPalindrome` should return `true` regardless of case.
+
+```js
+assert.isTrue(isPalindrome("Level"));
+```
+
+`isPalindrome` should return `false` for a non-palindrome.
+
+```js
+assert.isFalse(isPalindrome("hello"));
+```
+
+`findPalindromeBreaks` should be a function.
+
+```js
+assert.isFunction(findPalindromeBreaks);
+```
+
+`findPalindromeBreaks` should return an empty array for empty input.
+
+```js
+assert.sameDeepOrderedMembers(findPalindromeBreaks([]), []);
+```
+
+`findPalindromeBreaks` should return the indices of non-palindromes.
+
+```js
+assert.sameDeepOrderedMembers(findPalindromeBreaks(["racecar", "hello", "level"]), [1]);
+```
+
+`findPalindromeBreaks` should return an empty array when all words are palindromes.
+
+```js
+assert.sameDeepOrderedMembers(findPalindromeBreaks(["racecar", "level", "aba"]), []);
+```
+
+`findRepeatedPhrases` should be a function.
+
+```js
+assert.isFunction(findRepeatedPhrases);
+```
+
+`findRepeatedPhrases` should return an empty array when `phraseLength` is greater than or equal to the length of `words`.
+
+```js
+assert.sameDeepOrderedMembers(findRepeatedPhrases(["the", "cat"], 2), []);
+```
+
+`findRepeatedPhrases` should return an empty array when `phraseLength` is greater than the length of `words`.
+
+```js
+assert.sameDeepOrderedMembers(findRepeatedPhrases(["the"], 2), []);
+```
+
+`findRepeatedPhrases` should return all start indices where the phrase repeats, including the first occurrence.
+
+```js
+assert.sameDeepOrderedMembers(findRepeatedPhrases(["the", "cat", "sat", "the", "cat"], 2), [0, 3]);
+```
+
+`analyzeTexts` should be a function.
+
+```js
+assert.isFunction(analyzeTexts);
+```
+
+`analyzeTexts` should return an empty array for empty input.
+
+```js
+assert.sameDeepOrderedMembers(analyzeTexts([], 2), []);
+```
+
+`analyzeTexts` result objects should have `repeatedPhrases` and `palindromeBreaks` properties.
+
+```js
+const result = analyzeTexts([["racecar", "hello"]], 2);
+assert.property(result[0], "repeatedPhrases");
+assert.property(result[0], "palindromeBreaks");
+```
+
+`analyzeTexts` should correctly aggregate results for each text.
+
+```js
+const result = analyzeTexts([["racecar", "hello", "level", "hello"]], 1);
+assert.sameDeepOrderedMembers(result[0].repeatedPhrases, [1, 3]);
+assert.sameDeepOrderedMembers(result[0].palindromeBreaks, [1, 3]);
+```
+
+`analyzeTexts` should process multiple texts and return a result for each.
+
+```js
+const result = analyzeTexts([["racecar", "hello"], ["level", "world", "level"]], 1);
+assert.lengthOf(result, 2);
+assert.sameDeepOrderedMembers(result[1].palindromeBreaks, [1]);
+assert.sameDeepOrderedMembers(result[1].repeatedPhrases, [0, 2]);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```js
+
+```
+
+# --solutions--
+
+```js
+function isPalindrome(word) {
+  const lower = word.toLowerCase();
+  for (let i = 0; i < Math.floor(lower.length / 2); i++) {
+    if (lower[i] !== lower[lower.length - 1 - i]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+function findPalindromeBreaks(words) {
+  const breaks = [];
+  if (words.length === 0) return breaks;
+  for (let i = 0; i < words.length; i++) {
+    if (!isPalindrome(words[i])) {
+      breaks.push(i);
+    }
+  }
+  return breaks;
+}
+
+function findRepeatedPhrases(words, phraseLength) {
+  const result = [];
+  if (phraseLength >= words.length) return result;
+
+  for (let i = 0; i <= words.length - phraseLength; i++) {
+    const phrase = words.slice(i, i + phraseLength).join(" ");
+    let found = false;
+
+    for (let j = 0; j <= words.length - phraseLength; j++) {
+      if (i === j) continue;
+      if (words.slice(j, j + phraseLength).join(" ") === phrase) {
+        found = true;
+        break;
+      }
+    }
+
+    if (found) result.push(i);
+  }
+
+  return result;
+}
+
+function analyzeTexts(texts, phraseLength) {
+  const results = [];
+  if (texts.length === 0) return results;
+
+  for (let i = 0; i < texts.length; i++) {
+    results.push({
+      repeatedPhrases: findRepeatedPhrases(texts[i], phraseLength),
+      palindromeBreaks: findPalindromeBreaks(texts[i])
+    });
+  }
+
+  return results;
+}
+```
diff --git a/curriculum/structure/blocks/lab-proofreading-tool.json b/curriculum/structure/blocks/lab-proofreading-tool.json
new file mode 100644
index 00000000000..dbc7e5fcc8b
--- /dev/null
+++ b/curriculum/structure/blocks/lab-proofreading-tool.json
@@ -0,0 +1,14 @@
+{
+  "blockLabel": "lab",
+  "blockLayout": "link",
+  "isUpcomingChange": false,
+  "usesMultifileEditor": true,
+  "dashedName": "lab-proofreading-tool",
+  "helpCategory": "JavaScript",
+  "challengeOrder": [
+    {
+      "id": "69dd63d1dcdeccb7b39ba4c3",
+      "title": "Build a Proofreading Tool"
+    }
+  ]
+}
diff --git a/curriculum/structure/superblocks/javascript-v9.json b/curriculum/structure/superblocks/javascript-v9.json
index 972646ff3d7..e54ee867ce0 100644
--- a/curriculum/structure/superblocks/javascript-v9.json
+++ b/curriculum/structure/superblocks/javascript-v9.json
@@ -109,6 +109,7 @@
             "lab-repeat-a-string",
             "workshop-festival-crowd-flow-simulator",
             "lab-missing-letter-detector",
+            "lab-proofreading-tool",
             "review-javascript-loops",
             "quiz-javascript-loops"
           ]