diff --git a/src/PhpSpreadsheet/Calculation/Information/Value.php b/src/PhpSpreadsheet/Calculation/Information/Value.php
index 57a6704df..2f949cd05 100644
--- a/src/PhpSpreadsheet/Calculation/Information/Value.php
+++ b/src/PhpSpreadsheet/Calculation/Information/Value.php
@@ -265,7 +265,7 @@ class Value
         if (is_bool($value)) {
             return (int) $value;
         }
-        if (is_string($value) && substr($value, 0, 1) === '#') {
+        if (is_string($value) && str_starts_with($value, '#')) {
             return $value;
         }
 
diff --git a/src/PhpSpreadsheet/Cell/Coordinate.php b/src/PhpSpreadsheet/Cell/Coordinate.php
index 2a84c0deb..5aa96f44b 100644
--- a/src/PhpSpreadsheet/Cell/Coordinate.php
+++ b/src/PhpSpreadsheet/Cell/Coordinate.php
@@ -316,7 +316,7 @@ abstract class Coordinate
 
         $worksheet = $matches['worksheet'];
         if ($worksheet !== '') {
-            if (substr($worksheet, 0, 1) === "'" && substr($worksheet, -1, 1) === "'") {
+            if (str_starts_with($worksheet, "'") && str_ends_with($worksheet, "'")) {
                 $worksheet = substr($worksheet, 1, -1);
             }
             $data['worksheet'] = strtolower($worksheet);
diff --git a/src/PhpSpreadsheet/Reader/Html.php b/src/PhpSpreadsheet/Reader/Html.php
index 0723914b6..b6091ae29 100644
--- a/src/PhpSpreadsheet/Reader/Html.php
+++ b/src/PhpSpreadsheet/Reader/Html.php
@@ -1129,7 +1129,7 @@ class Html extends BaseReader
         $styleArray = self::getStyleArray($attributes);
 
         $src = $attributes['src'];
-        if (substr($src, 0, 5) !== 'data:') {
+        if (!str_starts_with($src, 'data:')) {
             $src = urldecode($src);
         }
         $width = isset($attributes['width']) ? (float) $attributes['width'] : ($styleArray['width'] ?? null);
@@ -1195,13 +1195,13 @@ class Html extends BaseReader
                     $arrayKey = trim($value[0]);
                     $arrayValue = trim($value[1]);
                     if ($arrayKey === 'width') {
-                        if (substr($arrayValue, -2) === 'px') {
+                        if (str_ends_with($arrayValue, 'px')) {
                             $arrayValue = (string) (((float) substr($arrayValue, 0, -2)));
                         } else {
                             $arrayValue = (new CssDimension($arrayValue))->toUnit(CssDimension::UOM_PIXELS);
                         }
                     } elseif ($arrayKey === 'height') {
-                        if (substr($arrayValue, -2) === 'px') {
+                        if (str_ends_with($arrayValue, 'px')) {
                             $arrayValue = substr($arrayValue, 0, -2);
                         } else {
                             $arrayValue = (new CssDimension($arrayValue))->toUnit(CssDimension::UOM_PIXELS);
diff --git a/src/PhpSpreadsheet/Reader/Security/XmlScanner.php b/src/PhpSpreadsheet/Reader/Security/XmlScanner.php
index e4da44f31..7b4e10431 100644
--- a/src/PhpSpreadsheet/Reader/Security/XmlScanner.php
+++ b/src/PhpSpreadsheet/Reader/Security/XmlScanner.php
@@ -64,7 +64,7 @@ class XmlScanner
 
     private function findCharSet(string $xml): string
     {
-        if (substr($xml, 0, 4) === "\x4c\x6f\xa7\x94") {
+        if (str_starts_with($xml, "\x4c\x6f\xa7\x94")) {
             throw new Reader\Exception('EBCDIC encoding not permitted');
         }
         $encoding = Reader\Csv::guessEncodingBom('', $xml);
diff --git a/src/PhpSpreadsheet/Reader/Xlsx.php b/src/PhpSpreadsheet/Reader/Xlsx.php
index 829f81fe3..2ae91dd6d 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx.php
@@ -2430,7 +2430,7 @@ class Xlsx extends BaseReader
                 $attrs = $rel->attributes() ?? [];
                 $rid = (string) ($attrs['Id'] ?? '');
                 $target = (string) ($attrs['Target'] ?? '');
-                if ($rid === $id && substr($target, 0, 2) === '..') {
+                if ($rid === $id && str_starts_with($target, '..')) {
                     $target = 'xl' . substr($target, 2);
                     $content = $this->getFromZipArchive($this->zip, $target);
                     $docSheet->setBackgroundImage($content);
diff --git a/src/PhpSpreadsheet/Worksheet/Worksheet.php b/src/PhpSpreadsheet/Worksheet/Worksheet.php
index 64c4ec23a..3defaea16 100644
--- a/src/PhpSpreadsheet/Worksheet/Worksheet.php
+++ b/src/PhpSpreadsheet/Worksheet/Worksheet.php
@@ -3411,7 +3411,7 @@ class Worksheet
     public static function unApostrophizeTitle(?string $title): string
     {
         $title ??= '';
-        if ($title[0] === "'" && substr($title, -1) === "'") {
+        if (str_starts_with($title, "'") && str_ends_with($title, "'")) {
             $title = str_replace("''", "'", substr($title, 1, -1));
         }