diff --git a/docs/demo/demo.js b/docs/demo/demo.js
index ec3aba0e..99e327ad 100644
--- a/docs/demo/demo.js
+++ b/docs/demo/demo.js
@@ -500,7 +500,7 @@
   load.data = function (dataArg) {
     const data = dataArg || {};
     dom.text(document.getElementById('description'), data.description || '');
-    if (data.url && trim(data.url).substr(0, 10) !== 'javascript') {
+    if (data.url && trim(data.url).substring(0, 10) !== 'javascript') {
       document.getElementById('external-link').setAttribute('href', data.url);
       document.getElementById('external-link').style.display = '';
     } else {
diff --git a/src/filters/arrays.js b/src/filters/arrays.js
index 477d26f9..18508e13 100644
--- a/src/filters/arrays.js
+++ b/src/filters/arrays.js
@@ -393,7 +393,7 @@ export const reverseFilter = function arraysReverseFilter(context) {
       context
         .setResult([
           context.delta[0],
-          parseInt(context.childName.substr(1), 10),
+          parseInt(context.childName.substring(1), 10),
           ARRAY_MOVE,
         ])
         .exit();
@@ -418,7 +418,7 @@ reverseFilter.filterName = 'arrays';
 
 const reverseArrayDeltaIndex = (delta, index, itemDelta) => {
   if (typeof index === 'string' && index[0] === '_') {
-    return parseInt(index.substr(1), 10);
+    return parseInt(index.substring(1), 10);
   } else if (isArray(itemDelta) && itemDelta[2] === 0) {
     return `_${index}`;
   }
@@ -428,7 +428,7 @@ const reverseArrayDeltaIndex = (delta, index, itemDelta) => {
     const deltaItem = delta[deltaIndex];
     if (isArray(deltaItem)) {
       if (deltaItem[2] === ARRAY_MOVE) {
-        const moveFromIndex = parseInt(deltaIndex.substr(1), 10);
+        const moveFromIndex = parseInt(deltaIndex.substring(1), 10);
         const moveToIndex = deltaItem[1];
         if (moveToIndex === +index) {
           return moveFromIndex;
@@ -442,7 +442,7 @@ const reverseArrayDeltaIndex = (delta, index, itemDelta) => {
           reverseIndex--;
         }
       } else if (deltaItem[2] === 0) {
-        const deleteIndex = parseInt(deltaIndex.substr(1), 10);
+        const deleteIndex = parseInt(deltaIndex.substring(1), 10);
         if (deleteIndex <= reverseIndex) {
           reverseIndex++;
         }
diff --git a/src/formatters/base.js b/src/formatters/base.js
index abf90028..5c7145d4 100644
--- a/src/formatters/base.js
+++ b/src/formatters/base.js
@@ -17,7 +17,7 @@ const getObjectKeys =
       };
 
 const trimUnderscore = (str) => {
-  if (str.substr(0, 1) === '_') {
+  if (str.substring(0, 1) === '_') {
     return str.slice(1);
   }
   return str;
@@ -27,7 +27,7 @@ const arrayKeyToSortNumber = (key) => {
   if (key === '_t') {
     return -1;
   } else {
-    if (key.substr(0, 1) === '_') {
+    if (key.substring(0, 1) === '_') {
       return parseInt(key.slice(1), 10);
     } else {
       return parseInt(key, 10) + 0.1;
@@ -159,7 +159,7 @@ class BaseFormatter {
         if (isArray(value) && value[2] === 3) {
           moveDestinations[value[1].toString()] = {
             key: name,
-            value: left && left[parseInt(name.substr(1))],
+            value: left && left[parseInt(name.substring(1))],
           };
           if (this.includeMoveDestinations !== false) {
             if (
@@ -247,9 +247,9 @@ class BaseFormatter {
         const pieceOutput = {
           type: 'context',
         };
-        if (piece.substr(0, 1) === '+') {
+        if (piece.substring(0, 1) === '+') {
           pieceOutput.type = 'added';
-        } else if (piece.substr(0, 1) === '-') {
+        } else if (piece.substring(0, 1) === '-') {
           pieceOutput.type = 'deleted';
         }
         pieceOutput.text = piece.slice(1);
diff --git a/test/examples/diffpatch.js b/test/examples/diffpatch.js
index 7af25870..c35a5193 100644
--- a/test/examples/diffpatch.js
+++ b/test/examples/diffpatch.js
@@ -596,8 +596,8 @@ examples.text = [
         minLength: 10,
       },
     },
-    left: largeText.substr(0, 10),
-    right: largeText.substr(0, 11).replace(/Madre/g, 'Padre'),
+    left: largeText.substring(0, 10),
+    right: largeText.substring(0, 11).replace(/Madre/g, 'Padre'),
     delta: ['@@ -1,10 +1,11 @@\n -\n-M\n+P\n adre,%0Acu\n+a\n', 0, 2],
     reverse: ['@@ -1,11 +1,10 @@\n -\n-P\n+M\n adre,%0Acu\n-a\n', 0, 2],
     exactReverse: false,
@@ -609,8 +609,8 @@ examples.text = [
         minLength: 10,
       },
     },
-    left: largeText.substr(0, 9),
-    right: largeText.substr(0, 11).replace(/Madre/g, 'Padre'),
+    left: largeText.substring(0, 9),
+    right: largeText.substring(0, 11).replace(/Madre/g, 'Padre'),
     delta: ['-Madre,\nc', '-Padre,\ncua'],
     reverse: ['-Padre,\ncua', '-Madre,\nc'],
     exactReverse: false,