diff --git a/string.asm b/string.asm
index 488be1f..aa17097 100644
--- a/string.asm
+++ b/string.asm
@@ -2,6 +2,7 @@ section	.text
 	global	strlen
 	global	strcpy
 	global	strcat
+	global	strcmp
 
 ;----- strlen(char* str) -----;
 ; return value: amount of characters before EOS was found
@@ -63,3 +64,33 @@ strcat:
 
 	leave
 	ret
+;----- strcmp(char* str1, char* str2) -----;
+; return value: 0 if both strings are the same, otherwise index in array str1 where strings are to become different
+; returns -1 if str2 is longer than str1 and no difference was found before that happens
+strcmp:
+	push	rbp
+	mov	rbp, rsp
+
+	call	strlen
+	mov	rcx, rax
+	mov	rax, -1
+	.compareLoop:
+		inc	rax
+		cmp	byte [rdi+rax], 0x0
+		je	.eosFound
+		mov	r10b, byte [rsi+rax]
+		cmp	byte [rdi+rax], r10b
+		je	.compareLoop
+	jmp	.quit
+
+	.eosFound:
+	mov	r10, rax
+	mov	rdi, rsi
+	call	strlen
+	cmp	rax, r10
+	jle	.quit
+	mov	rax, -1
+
+	.quit:
+	leave
+	ret
diff --git a/tests.asm b/tests.asm
index bda58d7..63a95d7 100644
--- a/tests.asm
+++ b/tests.asm
@@ -16,6 +16,7 @@ extern	puts
 extern	strlen
 extern	strcpy
 extern	strcat
+extern	strcmp
 
 section	.rodata
 	PRINT_nums	equ	1
@@ -31,6 +32,7 @@ section	.rodata
 	TEST_strcat	equ	1
 	TEST_tolower	equ	1
 	TEST_toupper	equ	1
+	TEST_strcmp	equ	1
 
 	num1		dq	13
 	num2		dq	-25
@@ -54,18 +56,21 @@ section	.rodata
 	msgIslower2	db	"islower(str1[1]): %d",10,0
 	msgIsupper	db	"isupper(str1[0]): %d",10,0
 	msgIsupper2	db	"isupper(str1[1]): %d",10,0
-	msgStrcpy	db	"strcpy(str1Copy, str1): %s",10,0
-	msgStrcat	db	"strcat(str1Copy, str3): %s",10,0
-	msgStrlen3	db	"strlen(str1Copy): %d",10,0
+	msgStrcpy	db	"strcpy(strBuff, str1): %s",10,0
+	msgStrcat	db	"strcat(strBuff, str3): %s",10,0
+	msgStrlen3	db	"strlen(strBuff): %d",10,0
 	msgTolower	db	"tolower(str1[0]): %c",10,0
 	msgTolower2	db	"tolower(str1[1]): %c",10,0
-	msgTolower3	db	"tolower() for whole str1Copy: %s",10,0
+	msgTolower3	db	"tolower() for whole strBuff: %s",10,0
 	msgToupper	db	"toupper(str1[0]): %c",10,0
 	msgToupper2	db	"toupper(str1[1]): %c",10,0
-	msgToupper3	db	"toupper() for whole str1Copy: %s",10,0
+	msgToupper3	db	"toupper() for whole strBuff: %s",10,0
+	msgStrcmp	db	"strcmp(str1, str2): %d",10,0
+	msgStrings2	db	"Comparing...",10,"> str1: %s",10,"> strBuff: %s",10,0
+	msgStrcmp2	db	"strcmp(str1, strBuff): %d",10,0
 section	.data
 section	.bss
-	str1Copy	resb	32
+	strBuff	resb	32
 section .text
 	global main
 main:
@@ -202,28 +207,28 @@ main:
 %ENDIF
 %IF TEST_strcpy
 	; TEST: strcpy()
-	lea	rdi, [rel str1Copy]
+	lea	rdi, [rel strBuff]
 	lea	rsi, [rel str1]
 	call	strcpy
 	xor	rax, rax
 	lea	rdi, [rel msgStrcpy]
-	lea	rsi, [rel str1Copy]
+	lea	rsi, [rel strBuff]
 	call	printf
 %ENDIF
 %IF TEST_strcat
 	; TEST: strcat()
-	lea	rdi, [rel str1Copy]
+	lea	rdi, [rel strBuff]
 	lea	rsi, [rel str3]
 	call	strcat
 	xor	rax, rax
 	lea	rdi, [rel msgStrcat]
-	lea	rsi, [rel str1Copy]
+	lea	rsi, [rel strBuff]
 	call	printf
 %ENDIF
 %IF TEST_strcat
 	%IF TEST_strlen
-	; TEST: strlen() for str1Copy
-	lea	rdi, [rel str1Copy]
+	; TEST: strlen() for strBuff
+	lea	rdi, [rel strBuff]
 	call	strlen
 	mov	rsi, rax
 	xor	rax, rax
@@ -264,8 +269,8 @@ main:
 	call	printf
 %ENDIF
 %IF TEST_tolower
-	; TEST: tolower: entire str1Copy
-	lea	rdi, [rel str1Copy]
+	; TEST: tolower: entire strBuff
+	lea	rdi, [rel strBuff]
 	call	strlen
 	mov	rcx, rax
 	.tolowerLoop:
@@ -282,12 +287,12 @@ main:
 		loop	.tolowerLoop
 	xor	rax, rax
 	lea	rdi, [rel msgTolower3]
-	lea	rsi, [rel str1Copy]
+	lea	rsi, [rel strBuff]
 	call	printf
 %ENDIF
 %IF TEST_toupper
-	; TEST: toupper: entire str1Copy
-	lea	rdi, [rel str1Copy]
+	; TEST: toupper: entire strBuff
+	lea	rdi, [rel strBuff]
 	call	strlen
 	mov	rcx, rax
 	.toupperLoop:
@@ -304,9 +309,39 @@ main:
 		loop	.toupperLoop
 	xor	rax, rax
 	lea	rdi, [rel msgToupper3]
-	lea	rsi, [rel str1Copy]
+	lea	rsi, [rel strBuff]
+	call	printf
+%ENDIF
+%IF TEST_strcmp
+	; TEST: strcmp(str1, str2)
+	lea	rdi, [rel str1]
+	lea	rsi, [rel str2]
+	call	strcmp
+	mov	rsi, rax
+	xor	rax, rax
+	lea	rdi, [rel msgStrcmp]
+	call	printf
+	;
+	lea	rdi, [rel strBuff]
+	lea	rsi, [rel str1]
+	call	strcpy
+	lea	rdi, [rel strBuff]
+	lea	rsi, [rel str3]
+	call	strcat
+	%IF PRINT_strs
+		xor	rax, rax
+		lea	rdi, [rel msgStrings2]
+		lea	rsi, [rel str1]
+		lea	rdx, [rel strBuff]
+		call	printf
+	%ENDIF
+	lea	rdi, [rel str1]
+	lea	rsi, [rel strBuff]
+	call	strcmp
+	mov	rsi, rax
+	xor	rax, rax
+	lea	rdi, [rel msgStrcmp2]
 	call	printf
 %ENDIF
-
 	leave
 	ret