diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index e17b605..e53938b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -25,5 +25,6 @@ endmacro()
 
 package_add_test(utility_test src/utility.cpp)
 package_add_test(parse_test src/parse.cpp)
-package_add_test(format_test src/format.cpp)
+package_add_test(format_decimal_test src/format_decimal.cpp)
+package_add_test(format_binary_test src/format_binary.cpp)
 
diff --git a/test/src/format.cpp b/test/src/format.cpp
index 33e1c42..d60712a 100644
--- a/test/src/format.cpp
+++ b/test/src/format.cpp
@@ -1,4 +1,4 @@
-#include <const_fmt/format.h>
+#include <const_fmt/format_decimal.h>
 #include <gtest/gtest.h>
 
 
@@ -6,7 +6,7 @@ using namespace const_fmt;
 using namespace const_fmt::const_fmt_detail;
 
 
-TEST(Format, positive_int) {
+TEST(FormatDecimal, positive_int) {
     constexpr std::array<char, 8> control1   = {'0', '0', '0', '0',
                                               '0', '0', '0', '2'};
     constexpr std::array<char, 8> formatted1 = const_format<"{:08}">(2);
@@ -32,7 +32,7 @@ TEST(Format, positive_int) {
     EXPECT_EQ(control5, formatted5);
 }
 
-TEST(Format, negative_int) {
+TEST(FormatDecimal, negative_int) {
     constexpr std::array<char, 8> control1   = {'-', '0', '0', '0',
                                               '0', '0', '0', '2'};
     constexpr std::array<char, 8> formatted1 = const_format<"{:08}">(-2);
@@ -58,7 +58,7 @@ TEST(Format, negative_int) {
     EXPECT_EQ(control5, formatted5);
 }
 
-TEST(Format, positive_float) {
+TEST(FormatDecimal, positive_float) {
     constexpr std::array<char, 8> control1   = {'0', '0', '2', '.',
                                               '3', '4', '5', '6'};
     constexpr std::array<char, 8> formatted1 = const_format<"{:08.4}">(2.3456);
@@ -82,7 +82,7 @@ TEST(Format, positive_float) {
     EXPECT_EQ(control4, formatted4);
 }
 
-TEST(Format, negative_float) {
+TEST(FormatDecimal, negative_float) {
     constexpr std::array<char, 8> control1   = {'-', '0', '2', '.',
                                                 '3', '4', '5', '6'};
     constexpr std::array<char, 8> formatted1 = const_format<"{:08.4}">(-2.3456);
@@ -100,9 +100,4 @@ TEST(Format, negative_float) {
     EXPECT_EQ(control1, formatted1);
     EXPECT_EQ(control2, formatted2);
     EXPECT_EQ(control3, formatted3);
-}
-//
-// TEST(Format, string) {
-//    // TODO
-//    EXPECT_EQ(true, false);
-//}
+}
\ No newline at end of file
diff --git a/test/src/format_binary.cpp b/test/src/format_binary.cpp
new file mode 100644
index 0000000..c5873b2
--- /dev/null
+++ b/test/src/format_binary.cpp
@@ -0,0 +1,59 @@
+#include <const_fmt/format_decimal.h>
+#include <gtest/gtest.h>
+
+
+using namespace const_fmt;
+using namespace const_fmt::const_fmt_detail;
+
+
+TEST(FormatBinary, positive_int) {
+    constexpr std::array<char, 8> control1   = {'0', '0', '0', '0',
+                                              '0', '0', '1', '0'};
+    constexpr std::array<char, 8> formatted1 = const_format<"{:08b}">(0b10);
+
+    constexpr std::array<char, 8> control2   = {' ', ' ', '1', '0',
+                                              '1', '0', '1', '0'};
+    constexpr std::array<char, 8> formatted2 = const_format<"{:8b}">(0b101010);
+
+    constexpr std::array<char, 8> control3   = {'0', '0', '0', '1',
+                                              '1', '0', '0', '1'};
+    constexpr std::array<char, 8> formatted3 = const_format<"{:08.4b}">(0b11001);
+
+    constexpr std::array<char, 4> control4   = {'1', '0', '1', '1'};
+    constexpr std::array<char, 4> formatted4 = const_format<"{:4b}">(0b1011);
+
+    constexpr std::array<char, 4> control5   = {'f', 'f', 'f', 'f'};
+    constexpr std::array<char, 4> formatted5 = const_format<"{:4b}">(0b10011);
+
+    EXPECT_EQ(control1, formatted1);
+    EXPECT_EQ(control2, formatted2);
+    EXPECT_EQ(control3, formatted3);
+    EXPECT_EQ(control4, formatted4);
+    EXPECT_EQ(control5, formatted5);
+}
+
+TEST(FormatBinary, negative_int) {
+    constexpr std::array<char, 8> control1   = {'-', '0', '0', '0',
+                                              '0', '0', '1', '0'};
+    constexpr std::array<char, 8> formatted1 = const_format<"{:08b}">(-0b10);
+
+    constexpr std::array<char, 8> control2   = {' ', '-', '1', '0',
+                                                '1', '0', '1', '0'};
+    constexpr std::array<char, 8> formatted2 = const_format<"{:8b}">(-0b101010);
+
+    constexpr std::array<char, 8> control3   = {'-', '0', '0', '1',
+                                              '0', '0', '1', '1'};
+    constexpr std::array<char, 8> formatted3 = const_format<"{:08.4b}">(-0b10011);
+
+    constexpr std::array<char, 5> control4   = {'-', '1', '1', '0', '1'};
+    constexpr std::array<char, 5> formatted4 = const_format<"{:5b}">(-0b1101);
+
+    constexpr std::array<char, 5> control5   = {'-', 'f', 'f', 'f', 'f'};
+    constexpr std::array<char, 5> formatted5 = const_format<"{:05b}">(-0b10101);
+
+    EXPECT_EQ(control1, formatted1);
+    EXPECT_EQ(control2, formatted2);
+    EXPECT_EQ(control3, formatted3);
+    EXPECT_EQ(control4, formatted4);
+    EXPECT_EQ(control5, formatted5);
+}
diff --git a/test/src/format_decimal.cpp b/test/src/format_decimal.cpp
new file mode 100644
index 0000000..16bc490
--- /dev/null
+++ b/test/src/format_decimal.cpp
@@ -0,0 +1,103 @@
+#include <const_fmt/format.h>
+#include <gtest/gtest.h>
+
+
+using namespace const_fmt;
+using namespace const_fmt::const_fmt_detail;
+
+
+TEST(FormatDecimal, positive_int) {
+    constexpr std::array<char, 8> control1   = {'0', '0', '0', '0',
+                                              '0', '0', '0', '2'};
+    constexpr std::array<char, 8> formatted1 = const_format<"{:08}">(2);
+
+    constexpr std::array<char, 8> control2   = {' ', ' ', ' ', '2',
+                                              '2', '2', '2', '2'};
+    constexpr std::array<char, 8> formatted2 = const_format<"{:8}">(22222);
+
+    constexpr std::array<char, 8> control3   = {'0', '0', '0', '1',
+                                              '2', '3', '4', '5'};
+    constexpr std::array<char, 8> formatted3 = const_format<"{:08.4}">(12345);
+
+    constexpr std::array<char, 4> control4   = {'6', '7', '8', '9'};
+    constexpr std::array<char, 4> formatted4 = const_format<"{:4}">(6789);
+
+    constexpr std::array<char, 4> control5   = {'f', 'f', 'f', 'f'};
+    constexpr std::array<char, 4> formatted5 = const_format<"{:4}">(67895);
+
+    EXPECT_EQ(control1, formatted1);
+    EXPECT_EQ(control2, formatted2);
+    EXPECT_EQ(control3, formatted3);
+    EXPECT_EQ(control4, formatted4);
+    EXPECT_EQ(control5, formatted5);
+}
+
+TEST(FormatDecimal, negative_int) {
+    constexpr std::array<char, 8> control1   = {'-', '0', '0', '0',
+                                              '0', '0', '0', '2'};
+    constexpr std::array<char, 8> formatted1 = const_format<"{:08}">(-2);
+
+    constexpr std::array<char, 8> control2   = {' ', ' ', '-', '2',
+                                              '2', '2', '2', '2'};
+    constexpr std::array<char, 8> formatted2 = const_format<"{:8}">(-22222);
+
+    constexpr std::array<char, 8> control3   = {'-', '0', '0', '1',
+                                              '2', '3', '4', '5'};
+    constexpr std::array<char, 8> formatted3 = const_format<"{:08.4}">(-12345);
+
+    constexpr std::array<char, 5> control4   = {'-', '6', '7', '8', '9'};
+    constexpr std::array<char, 5> formatted4 = const_format<"{:5}">(-6789);
+
+    constexpr std::array<char, 5> control5   = {'-', 'f', 'f', 'f', 'f'};
+    constexpr std::array<char, 5> formatted5 = const_format<"{:05}">(-66789);
+
+    EXPECT_EQ(control1, formatted1);
+    EXPECT_EQ(control2, formatted2);
+    EXPECT_EQ(control3, formatted3);
+    EXPECT_EQ(control4, formatted4);
+    EXPECT_EQ(control5, formatted5);
+}
+
+TEST(FormatDecimal, positive_float) {
+    constexpr std::array<char, 8> control1   = {'0', '0', '2', '.',
+                                              '3', '4', '5', '6'};
+    constexpr std::array<char, 8> formatted1 = const_format<"{:08.4}">(2.3456);
+
+    // Float error: 2323.2 -> 2323.1
+    constexpr std::array<char, 8> control2   = {' ', ' ', '2', '3',
+                                              '2', '3', '.', '1'};
+    constexpr std::array<char, 8> formatted2 = const_format<"{:8.1}">(2323.2);
+
+    constexpr std::array<char, 8> control3   = {'1', '2', '3', '4',
+                                              '.', '5', '0', '0'};
+    constexpr std::array<char, 8> formatted3 = const_format<"{:08.3}">(1234.5);
+
+    // Float error: .9 -> .8
+    constexpr std::array<char, 4> control4   = {'f', 'f', '.', '8'};
+    constexpr std::array<char, 4> formatted4 = const_format<"{:4.1}">(678.9);
+
+    EXPECT_EQ(control1, formatted1);
+    EXPECT_EQ(control2, formatted2);
+    EXPECT_EQ(control3, formatted3);
+    EXPECT_EQ(control4, formatted4);
+}
+
+TEST(FormatDecimal, negative_float) {
+    constexpr std::array<char, 8> control1   = {'-', '0', '2', '.',
+                                                '3', '4', '5', '6'};
+    constexpr std::array<char, 8> formatted1 = const_format<"{:08.4}">(-2.3456);
+
+    // Float error: 2323.2 -> 2323.1
+    constexpr std::array<char, 8> control2   = {' ', '-', '2', '3',
+                                                '2', '3', '.', '1'};
+    constexpr std::array<char, 8> formatted2 = const_format<"{:8.1}">(-2323.2);
+
+    constexpr std::array<char, 8> control3   = {'-', 'f', 'f', 'f',
+                                                '.', '5', '0', '0'};
+    constexpr std::array<char, 8> formatted3 = const_format<"{:08.3}">(-1234.5);
+
+
+    EXPECT_EQ(control1, formatted1);
+    EXPECT_EQ(control2, formatted2);
+    EXPECT_EQ(control3, formatted3);
+}
\ No newline at end of file