diff --git a/4dev/tests/CoreLibsConvertStringsTest.php b/4dev/tests/CoreLibsConvertStringsTest.php
new file mode 100644
index 00000000..7e71355f
--- /dev/null
+++ b/4dev/tests/CoreLibsConvertStringsTest.php
@@ -0,0 +1,142 @@
+<?php // phpcs:disable Generic.Files.LineLength
+
+declare(strict_types=1);
+
+namespace tests;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Test class for Convert\Strings
+ * @coversDefaultClass \CoreLibs\Convert\Strings
+ * @testdox \CoreLibs\Convert\Strings method tests
+ */
+final class CoreLibsConvertStringsTest extends TestCase
+{
+	public function splitFormatStringProvider(): array
+	{
+		// 0: input
+		// 1: format
+		// 2: split characters as string, null for default
+		// 3: expected
+		return [
+			'all empty string' => [
+				'',
+				'',
+				null,
+				''
+			],
+			'empty input string' => [
+				'',
+				'2-2',
+				null,
+				''
+			],
+			'empty format string string' => [
+				'1234',
+				'',
+				null,
+				'1234'
+			],
+			'string format match' => [
+				'1234',
+				'2-2',
+				null,
+				'12-34'
+			],
+			'string format short first' => [
+				'1',
+				'2-2',
+				null,
+				'1'
+			],
+			'string format match first' => [
+				'12',
+				'2-2',
+				null,
+				'12'
+			],
+			'string format short second' => [
+				'123',
+				'2-2',
+				null,
+				'12-3'
+			],
+			'string format too long' => [
+				'1234567',
+				'2-2',
+				null,
+				'12-34-567'
+			],
+			'string format invalid format string' => [
+				'1234',
+				'2_2',
+				null,
+				'1234'
+			],
+			'different split character' => [
+				'1234',
+				'2_2',
+				'_',
+				'12_34'
+			],
+			'mixed split characters' => [
+				'123456',
+				'2-2_2',
+				'-_',
+				'12-34_56'
+			],
+			'length mixed' => [
+				'ABCD12345568ABC13',
+				'2-4_5-2#4',
+				'-_#',
+				'AB-CD12_34556-8A#BC13'
+			],
+			'split with split chars in string' => [
+				'12-34',
+				'2-2',
+				null,
+				'12--3-4'
+			]
+		];
+	}
+
+	/**
+	 * split format string
+	 *
+	 * @covers ::splitFormatString
+	 * @dataProvider splitFormatStringProvider
+	 * @testdox splitFormatString $input with format $format and splitters $split_characters will be $expected [$_dataName]
+	 *
+	 * @param  string      $input
+	 * @param  string      $format
+	 * @param  string|null $split_characters
+	 * @param  string      $expected
+	 * @return void
+	 */
+	public function testSplitFormatString(
+		string $input,
+		string $format,
+		?string $split_characters,
+		string $expected
+	): void {
+		if ($split_characters === null) {
+			$output = \CoreLibs\Convert\Strings::splitFormatString(
+				$input,
+				$format
+			);
+		} else {
+			$output = \CoreLibs\Convert\Strings::splitFormatString(
+				$input,
+				$format,
+				$split_characters
+			);
+		}
+		$this->assertEquals(
+			$expected,
+			$output
+		);
+	}
+}
+
+// __END__
diff --git a/www/admin/class_test.php b/www/admin/class_test.php
index 4c8c685b..5fbc9129 100644
--- a/www/admin/class_test.php
+++ b/www/admin/class_test.php
@@ -70,6 +70,7 @@ print '<div><a href="class_test.hash.php">Class Test: HASH</a></div>';
 print '<div><a href="class_test.encoding.php">Class Test: ENCODING (CHECK/CONVERT/MIME)</a></div>';
 print '<div><a href="class_test.image.php">Class Test: IMAGE</a></div>';
 print '<div><a href="class_test.byte.php">Class Test: BYTE CONVERT</a></div>';
+print '<div><a href="class_test.strings.php">Class Test: STRING CONVERT</a></div>';
 print '<div><a href="class_test.datetime.php">Class Test: DATE/TIME</a></div>';
 print '<div><a href="class_test.array.php">Class Test: ARRAY HANDLER</a></div>';
 print '<div><a href="class_test.file.php">Class Test: FILE</a></div>';
diff --git a/www/admin/class_test.strings.php b/www/admin/class_test.strings.php
new file mode 100644
index 00000000..7681110d
--- /dev/null
+++ b/www/admin/class_test.strings.php
@@ -0,0 +1,73 @@
+<?php // phpcs:ignore warning
+
+declare(strict_types=1);
+
+$DEBUG_ALL_OVERRIDE = 0; // set to 1 to debug on live/remote server locations
+$DEBUG_ALL = 1;
+$PRINT_ALL = 1;
+$DB_DEBUG = 1;
+
+if ($DEBUG_ALL) {
+	error_reporting(E_ALL | E_STRICT | E_ERROR | E_WARNING | E_PARSE | E_COMPILE_ERROR);
+}
+
+ob_start();
+
+// basic class test file
+define('USE_DATABASE', false);
+// sample config
+require 'config.php';
+// define log file id
+$LOG_FILE_ID = 'classTest-string';
+ob_end_flush();
+
+use CoreLibs\Convert\Byte;
+
+$log = new CoreLibs\Debug\Logging([
+	'log_folder' => BASE . LOG,
+	'file_id' => $LOG_FILE_ID,
+	// add file date
+	'print_file_date' => true,
+	// set debug and print flags
+	'debug_all' => $DEBUG_ALL ?? false,
+	'echo_all' => $ECHO_ALL ?? false,
+	'print_all' => $PRINT_ALL ?? false,
+]);
+$byte_class = 'CoreLibs\Convert\Strings';
+
+$PAGE_NAME = 'TEST CLASS: STRINGS CONVERT';
+print "<!DOCTYPE html>";
+print "<html><head><title>" . $PAGE_NAME . "</title><head>";
+print "<body>";
+print '<div><a href="class_test.php">Class Test Master</a></div>';
+print '<div><h1>' . $PAGE_NAME . '</h1></div>';
+
+$split = '4-4-4';
+$test_strings = [
+	'13',
+	'1234',
+	'12341',
+	'12341234',
+	'123412341',
+	'123412341234',
+	'1234123412341234512345',
+];
+
+foreach ($test_strings as $string) {
+	print "Convert: $string with $split to: "
+		. \CoreLibs\Convert\Strings::splitFormatString($string, $split)
+		. "<br>";
+}
+
+$split = '2_2';
+$string = '1234';
+print "Convert: $string with $split to: "
+	. \CoreLibs\Convert\Strings::splitFormatString($string, $split)
+	. "<br>";
+
+// error message
+print $log->printErrorMsg();
+
+print "</body></html>";
+
+// __END__
diff --git a/www/lib/CoreLibs/Convert/Strings.php b/www/lib/CoreLibs/Convert/Strings.php
new file mode 100644
index 00000000..324083af
--- /dev/null
+++ b/www/lib/CoreLibs/Convert/Strings.php
@@ -0,0 +1,81 @@
+<?php
+
+/*
+ * string convert and transform functions
+ */
+
+declare(strict_types=1);
+
+namespace CoreLibs\Convert;
+
+class Strings
+{
+	/**
+	 * split format a string base on a split format string
+	 * split format string is eg
+	 * 4-4-4 that means 4 characters DASH 4 characters DASH 4 characters
+	 * So a string in the format of
+	 * ABCD1234EFGH will be ABCD-1234-EFGH
+	 * Note a string LONGER then the maxium will be attached with the LAST
+	 * split character. In above exmaple
+	 * ABCD1234EFGHTOOLONG will be ABCD-1234-EFGH-TOOLONG
+	 *
+	 * @param  string $value            string value to split
+	 * @param  string $split_format     split format
+	 * @param  string $split_characters list of charcters with which we split
+	 *                                  if not set uses dash ('-')
+	 * @return string                   split formatted string or original value if not chnaged
+	 */
+	public static function splitFormatString(
+		string $value,
+		string $split_format,
+		string $split_charcters = '-'
+	): string {
+		// abort if split format is empty
+		if (empty($split_format)) {
+			return $value;
+		}
+		$split_list = preg_split(
+			// allowed split characters
+			"/([" . $split_charcters . "]{1})/",
+			$split_format,
+			-1,
+			PREG_SPLIT_DELIM_CAPTURE
+		);
+		// if this is false, or only one array, abort split
+		if (!is_array($split_list) || count($split_list) == 1) {
+			return $value;
+		}
+		$out = '';
+		$pos = 0;
+		$last_split = '';
+		foreach ($split_list as $offset) {
+			if (is_numeric($offset)) {
+				$_part = substr($value, $pos, (int)$offset);
+				if (empty($_part)) {
+					break;
+				}
+				$out .= $_part;
+				$pos += (int)$offset;
+			} else {
+				$out .= $offset;
+				$last_split = $offset;
+			}
+		}
+		if (!empty($out) && $pos < strlen($value)) {
+			$out .= $last_split . substr($value, $pos);
+		}
+		// if last is not alphanumeric remove, remove
+		if (!strcspn(substr($out, -1, 1), $split_charcters)) {
+			$out = substr($out, 0, -1);
+		}
+		// overwrite only if out is set
+		if (!empty($out)) {
+			return $out;
+		} else {
+			return $value;
+		}
+	}
+}
+
+// __END__
diff --git a/www/vendor/composer/autoload_classmap.php b/www/vendor/composer/autoload_classmap.php
index 6abe21a4..bf15237c 100644
--- a/www/vendor/composer/autoload_classmap.php
+++ b/www/vendor/composer/autoload_classmap.php
@@ -27,6 +27,7 @@ return array(
     'CoreLibs\\Convert\\Math' => $baseDir . '/lib/CoreLibs/Convert/Math.php',
     'CoreLibs\\Convert\\MimeAppName' => $baseDir . '/lib/CoreLibs/Convert/MimeAppName.php',
     'CoreLibs\\Convert\\MimeEncode' => $baseDir . '/lib/CoreLibs/Convert/MimeEncode.php',
+    'CoreLibs\\Convert\\Strings' => $baseDir . '/lib/CoreLibs/Convert/Strings.php',
     'CoreLibs\\Create\\Email' => $baseDir . '/lib/CoreLibs/Create/Email.php',
     'CoreLibs\\Create\\Hash' => $baseDir . '/lib/CoreLibs/Create/Hash.php',
     'CoreLibs\\Create\\RandomKey' => $baseDir . '/lib/CoreLibs/Create/RandomKey.php',
diff --git a/www/vendor/composer/autoload_static.php b/www/vendor/composer/autoload_static.php
index e150912e..ee64a887 100644
--- a/www/vendor/composer/autoload_static.php
+++ b/www/vendor/composer/autoload_static.php
@@ -92,6 +92,7 @@ class ComposerStaticInit10fe8fe2ec4017b8644d2b64bcf398b9
         'CoreLibs\\Convert\\Math' => __DIR__ . '/../..' . '/lib/CoreLibs/Convert/Math.php',
         'CoreLibs\\Convert\\MimeAppName' => __DIR__ . '/../..' . '/lib/CoreLibs/Convert/MimeAppName.php',
         'CoreLibs\\Convert\\MimeEncode' => __DIR__ . '/../..' . '/lib/CoreLibs/Convert/MimeEncode.php',
+        'CoreLibs\\Convert\\Strings' => __DIR__ . '/../..' . '/lib/CoreLibs/Convert/Strings.php',
         'CoreLibs\\Create\\Email' => __DIR__ . '/../..' . '/lib/CoreLibs/Create/Email.php',
         'CoreLibs\\Create\\Hash' => __DIR__ . '/../..' . '/lib/CoreLibs/Create/Hash.php',
         'CoreLibs\\Create\\RandomKey' => __DIR__ . '/../..' . '/lib/CoreLibs/Create/RandomKey.php',