diff --git a/char/ft_isascii.c b/char/ft_isascii.c
index 5bcccc3..8ed7e6d 100644
--- a/char/ft_isascii.c
+++ b/char/ft_isascii.c
@@ -6,7 +6,7 @@
 /*   By: rparodi <marvin@42.fr>                     +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2023/11/06 14:04:26 by rparodi           #+#    #+#             */
-/*   Updated: 2025/09/04 11:41:42 by rparodi          ###   ########.fr       */
+/*   Updated: 2025/09/05 10:40:03 by rparodi          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -21,6 +21,6 @@ int	ft_isascii(int c)
 	if (c == 0)
 		return (1);
 	if (c > 0 && c <= 127)
-		return (c);
+		return (1);
 	return (0);
 }
diff --git a/char/ft_isprint.c b/char/ft_isprint.c
index 7da8b4f..c4c38c4 100644
--- a/char/ft_isprint.c
+++ b/char/ft_isprint.c
@@ -6,7 +6,7 @@
 /*   By: rparodi <marvin@42.fr>                     +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2023/11/06 14:06:53 by rparodi           #+#    #+#             */
-/*   Updated: 2025/09/04 11:41:49 by rparodi          ###   ########.fr       */
+/*   Updated: 2025/09/05 10:44:13 by rparodi          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -19,6 +19,6 @@
 int	ft_isprint(int c)
 {
 	if (c >= 32 && c <= 126)
-		return (c);
+		return (1);
 	return (0);
 }
diff --git a/test/char/test_isascii.c b/test/char/test_isascii.c
new file mode 100644
index 0000000..932b79e
--- /dev/null
+++ b/test/char/test_isascii.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   test_isascii.c                                     :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: rparodi <rparodi@student.42.fr>            +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/09/04 16:54:42 by rparodi           #+#    #+#             */
+/*   Updated: 2025/09/05 10:40:18 by rparodi          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "char.h"
+#include "color.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int	main(void)
+{
+	unsigned char	c;
+
+	c = 0;
+	while (c <= 128)
+	{
+		if (ft_isascii(c) != isascii(c))
+		{
+			printf("%s✘ Found %i, excepted %i%s\n", CLR_RED, ft_isascii(c),
+				isascii(c), RESET);
+			exit(1);
+		}
+		else
+			printf("%s✔%s ", CLR_GREEN, RESET);
+		c++;
+	}
+}
diff --git a/test/char/test_isprint.c b/test/char/test_isprint.c
new file mode 100644
index 0000000..d3fca7e
--- /dev/null
+++ b/test/char/test_isprint.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   test_isprint.c                                     :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: rparodi <rparodi@student.42.fr>            +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/09/04 16:54:42 by rparodi           #+#    #+#             */
+/*   Updated: 2025/09/05 10:43:55 by rparodi          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "char.h"
+#include "color.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int	main(void)
+{
+	unsigned char	c;
+
+	c = 0;
+	while (c <= 128)
+	{
+		if (ft_isprint(c) != isprint(c))
+		{
+			printf("%s✘ Found %i, excepted %i%s\n", CLR_RED, ft_isprint(c),
+				isprint(c), RESET);
+			exit(1);
+		}
+		else
+			printf("%s✔%s ", CLR_GREEN, RESET);
+		c++;
+	}
+}
diff --git a/test/char/test_tolower.c b/test/char/test_tolower.c
new file mode 100644
index 0000000..73f05aa
--- /dev/null
+++ b/test/char/test_tolower.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   test_tolower.c                                     :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: rparodi <rparodi@student.42.fr>            +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/09/04 16:54:42 by rparodi           #+#    #+#             */
+/*   Updated: 2025/09/05 10:35:53 by rparodi          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "char.h"
+#include "color.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int	main(void)
+{
+	unsigned char	c;
+
+	c = 0;
+	while (c <= 128)
+	{
+		if (ft_tolower(c) != tolower(c))
+		{
+			printf("%s✘ Found %i, excepted %i%s\n", CLR_RED, ft_tolower(c),
+				tolower(c), RESET);
+			exit(1);
+		}
+		else
+			printf("%s✔%s ", CLR_GREEN, RESET);
+		c++;
+	}
+}
diff --git a/test/char/test_toupper.c b/test/char/test_toupper.c
new file mode 100644
index 0000000..b2b1d61
--- /dev/null
+++ b/test/char/test_toupper.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   test_toupper.c                                     :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: rparodi <rparodi@student.42.fr>            +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/09/04 16:54:42 by rparodi           #+#    #+#             */
+/*   Updated: 2025/09/05 10:37:26 by rparodi          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "char.h"
+#include "color.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int	main(void)
+{
+	unsigned char	c;
+
+	c = 0;
+	while (c <= 128)
+	{
+		if (ft_toupper(c) != toupper(c))
+		{
+			printf("%s✘ Found %i, excepted %i%s\n", CLR_RED, ft_toupper(c),
+				toupper(c), RESET);
+			exit(1);
+		}
+		else
+			printf("%s✔%s ", CLR_GREEN, RESET);
+		c++;
+	}
+}