diff --git a/wasm/test_page/js/worker.js b/wasm/test_page/js/worker.js
index a2761a4a0..4c1c640f1 100644
--- a/wasm/test_page/js/worker.js
+++ b/wasm/test_page/js/worker.js
@@ -85,7 +85,8 @@ const constructTranslationService = async () => {
   }
 }
 
-// Constructs translation model for the source and target language pair.
+// Constructs translation model(s) for the source and target language pair (using
+// pivoting if required).
 const constructTranslationModel = async (from, to) => {
   // Delete all previously constructed translation models and clear the map
   languagePairToTranslationModels.forEach((value, key) => {
@@ -94,62 +95,63 @@ const constructTranslationModel = async (from, to) => {
   });
   languagePairToTranslationModels.clear();
 
-  const languagePairs = _getLanguagePairs(from, to);
-  log(`Constructing translation model(s): ${languagePairs.toString()}`);
-  if (languagePairs.length == 2) {
-    // This implies pivoting is required => Construct 2 translation models
-    await Promise.all([_constructTranslationModelHelper(languagePairs[0]),
-                      _constructTranslationModelHelper(languagePairs[1])]);
+  if (_isPivotingRequired(from, to)) {
+    // Pivoting requires 2 translation models
+    const languagePairSrcToPivot = _getLanguagePair(from, PIVOT_LANGUAGE);
+    const languagePairPivotToTarget = _getLanguagePair(PIVOT_LANGUAGE, to);
+    await Promise.all([_constructTranslationModelHelper(languagePairSrcToPivot),
+                      _constructTranslationModelHelper(languagePairPivotToTarget)]);
   }
   else {
-    // This implies pivoting is not required => Construct 1 translation model
-    await _constructTranslationModelHelper(languagePairs[0]);
+    // Non-pivoting case requires only 1 translation model
+    await _constructTranslationModelHelper(_getLanguagePair(from, to));
   }
 }
 
 // Translates text from source language to target language (via pivoting if necessary).
 const translate = (from, to, input, translateOptions) => {
-  const languagePairs = _getLanguagePairs(from, to);
-  log(`Translating for language pair(s): '${languagePairs.toString()}'`);
-
-  // Each language pair requires a corresponding loaded translation model. Otherwise, it's an error.
-  let translationModels = _getLoadedTranslationModels(from, to);
-  if (translationModels.length != languagePairs.length) {
-    throw Error(`Insufficient no. of loaded translation models. Required:'${languagePairs.length}' Found:'${translationModels.length}'`);
-  }
+  let vectorResponseOptions, vectorSourceText, vectorResponse;
+  try {
+    // Prepare the arguments (vectorResponseOptions and vectorSourceText (vector<string>)) of Translation API and call it.
+    // Result is a vector<Response> where each of its item corresponds to one item of vectorSourceText in the same order.
+    vectorResponseOptions = _prepareResponseOptions(translateOptions);
+    vectorSourceText = _prepareSourceText(input);
+
+    if (_isPivotingRequired(from, to)) {
+      // Translate via pivoting
+      const translationModelSrcToPivot = _getLoadedTranslationModel(from, PIVOT_LANGUAGE);
+      const translationModelPivotToTarget = _getLoadedTranslationModel(PIVOT_LANGUAGE, to);
+      vectorResponse = translationService.translateViaPivoting(translationModelSrcToPivot,
+                                                              translationModelPivotToTarget,
+                                                              vectorSourceText,
+                                                              vectorResponseOptions);
+    }
+    else {
+      // Translate without pivoting
+      const translationModel = _getLoadedTranslationModel(from, to);
+      vectorResponse = translationService.translate(translationModel, vectorSourceText, vectorResponseOptions);
+    }
 
-  // Prepare the arguments (vectorResponseOptions and vectorSourceText (vector<string>)) of Translation API and call it.
-  // Result is a vector<Response> where each of its item corresponds to one item of vectorSourceText in the same order.
-  const vectorResponseOptions = _prepareResponseOptions(translateOptions);
-  let vectorSourceText = _prepareSourceText(input);
-  let vectorResponse;
-  if (translationModels.length == 2) {
-    // This implies translation should be done via pivoting
-    vectorResponse = translationService.translateViaPivoting(translationModels[0], translationModels[1], vectorSourceText, vectorResponseOptions);
+    // Parse all relevant information from vectorResponse
+    const listTranslatedText = _parseTranslatedText(vectorResponse);
+    const listSourceText = _parseSourceText(vectorResponse);
+    const listTranslatedTextSentences = _parseTranslatedTextSentences(vectorResponse);
+    const listSourceTextSentences = _parseSourceTextSentences(vectorResponse);
+    const listTranslatedTextSentenceQualityScores = _parseTranslatedTextSentenceQualityScores(vectorResponse);
+
+    log(`Source text: ${listSourceText}`);
+    log(`Translated text: ${listTranslatedText}`);
+    log(`Translated sentences: ${JSON.stringify(listTranslatedTextSentences)}`);
+    log(`Source sentences: ${JSON.stringify(listSourceTextSentences)}`);
+    log(`Translated sentence quality scores: ${JSON.stringify(listTranslatedTextSentenceQualityScores)}`);
+
+    return listTranslatedText;
+  } finally {
+    // Necessary clean up
+    if (vectorSourceText != null) vectorSourceText.delete();
+    if (vectorResponseOptions != null) vectorResponseOptions.delete();
+    if (vectorResponse != null) vectorResponse.delete();
   }
-  else {
-    // This implies translation should be done without pivoting
-    vectorResponse = translationService.translate(translationModels[0], vectorSourceText, vectorResponseOptions);
-  }
-
-  // Parse all relevant information from vectorResponse
-  const listTranslatedText = _parseTranslatedText(vectorResponse);
-  const listSourceText = _parseSourceText(vectorResponse);
-  const listTranslatedTextSentences = _parseTranslatedTextSentences(vectorResponse);
-  const listSourceTextSentences = _parseSourceTextSentences(vectorResponse);
-  const listTranslatedTextSentenceQualityScores = _parseTranslatedTextSentenceQualityScores(vectorResponse);
-
-  log(`Source text: ${listSourceText}`);
-  log(`Translated text: ${listTranslatedText}`);
-  log(`Translated sentences: ${JSON.stringify(listTranslatedTextSentences)}`);
-  log(`Source sentences: ${JSON.stringify(listSourceTextSentences)}`);
-  log(`Translated sentence quality scores: ${JSON.stringify(listTranslatedTextSentenceQualityScores)}`);
-
-  // Delete prepared SourceText to avoid memory leak
-  vectorSourceText.delete();
-  vectorResponseOptions.delete();
-
-  return listTranslatedText;
 }
 
 // Downloads file from a url and returns the array buffer
@@ -174,6 +176,7 @@ const _prepareAlignedMemoryFromBuffer = async (buffer, alignmentSize) => {
 }
 
 const _constructTranslationModelHelper = async (languagePair) => {
+  log(`Constructing translation model ${languagePair}`);
 
   /*Set the Model Configuration as YAML formatted string.
     For available configuration options, please check: https://marian-nmt.github.io/docs/cmd/marian-decoder/
@@ -237,35 +240,20 @@ alignment: soft
   languagePairToTranslationModels.set(languagePair, translationModel);
 }
 
-const _isPivotingRequired = (lang1, lang2) => {
-  if ((lang1 === PIVOT_LANGUAGE) || (lang2 === PIVOT_LANGUAGE)) {
-    return false;
-  }
-  return true;
+const _isPivotingRequired = (from, to) => {
+  return (from !== PIVOT_LANGUAGE) && (to !== PIVOT_LANGUAGE);
 }
 
-const _getLanguagePairs = (srcLang, tgtLang) => {
-  const languagePairs = [];
-  if (_isPivotingRequired(srcLang, tgtLang)) {
-    // Do not change the push order
-    languagePairs.push(`${srcLang}${PIVOT_LANGUAGE}`);
-    languagePairs.push(`${PIVOT_LANGUAGE}${tgtLang}`);
-  }
-  else {
-    languagePairs.push(`${srcLang}${tgtLang}`);
-  }
-  return languagePairs;
+const _getLanguagePair = (srcLang, tgtLang) => {
+  return `${srcLang}${tgtLang}`;
 }
 
-const _getLoadedTranslationModels = (srcLang, tgtLang) => {
-  const languagePairs = _getLanguagePairs(srcLang, tgtLang);
-  const loadedTranslationModels = [];
-  for (const langPair of languagePairs) {
-    if (languagePairToTranslationModels.has(langPair)) {
-      loadedTranslationModels.push(languagePairToTranslationModels.get(langPair));
-    }
+const _getLoadedTranslationModel = (srcLang, tgtLang) => {
+  const languagePair = _getLanguagePair(srcLang, tgtLang);
+  if (!languagePairToTranslationModels.has(languagePair)) {
+    throw Error(`Translation model '${languagePair}' not loaded`);
   }
-  return loadedTranslationModels;
+  return languagePairToTranslationModels.get(languagePair);
 }
 
 const _parseTranslatedText = (vectorResponse) => {
@@ -343,10 +331,18 @@ const _parseTranslatedTextSentenceQualityScores = (vectorResponse) => {
 }
 
 const _prepareResponseOptions = (translateOptions) => {
-  const vectorResponseOptions = new Module.VectorResponseOptions;
+  let vectorResponseOptions = new Module.VectorResponseOptions;
   translateOptions.forEach(translateOption => {
-    vectorResponseOptions.push_back({qualityScores: translateOption["isQualityScores"], alignment: true, html: translateOption["isHtml"]});
+    vectorResponseOptions.push_back({
+      qualityScores: translateOption["isQualityScores"],
+      alignment: true,
+      html: translateOption["isHtml"]
+    });
   });
+  if (vectorResponseOptions.size() == 0) {
+    vectorResponseOptions.delete();
+    throw Error(`No Translation Options provided`);
+  }
   return vectorResponseOptions;
 }
 
@@ -359,6 +355,10 @@ const _prepareSourceText = (input) => {
     }
     vectorSourceText.push_back(paragraph.trim())
   })
+  if (vectorSourceText.size() == 0) {
+    vectorSourceText.delete();
+    throw Error(`No text provided to translate`);
+  }
   return vectorSourceText;
 }