diff --git a/src/main/java/net/minestom/server/utils/PacketUtils.java b/src/main/java/net/minestom/server/utils/PacketUtils.java
index 5086ef955..26f087efa 100644
--- a/src/main/java/net/minestom/server/utils/PacketUtils.java
+++ b/src/main/java/net/minestom/server/utils/PacketUtils.java
@@ -198,18 +198,16 @@ public final class PacketUtils {
         final int compressionThreshold = MinecraftServer.getCompressionThreshold();
         final boolean compression = compressionThreshold > 0;
 
-        final int hardcodedVarIntSize = 3;
-
         if (compression) {
             // Dummy varint
-            final int packetLengthIndex = Utils.writeEmptyVarInt(buffer, hardcodedVarIntSize);
-            final int dataLengthIndex = Utils.writeEmptyVarInt(buffer, hardcodedVarIntSize);
+            final int packetLengthIndex = Utils.writeEmptyVarIntHeader(buffer);
+            final int dataLengthIndex = Utils.writeEmptyVarIntHeader(buffer);
 
             // Write packet
             final int contentIndex = buffer.writerIndex();
             writePacket(buffer, serverPacket);
             final int afterIndex = buffer.writerIndex();
-            final int packetSize = (afterIndex - dataLengthIndex) - hardcodedVarIntSize;
+            final int packetSize = (afterIndex - dataLengthIndex) - Utils.VARINT_HEADER_SIZE;
 
             if (packetSize >= compressionThreshold) {
                 // Packet large enough
@@ -221,30 +219,30 @@ public final class PacketUtils {
                 compress(deflater, uncompressedCopy, buffer);
                 uncompressedCopy.release();
 
-                final int totalPacketLength = buffer.writerIndex() - contentIndex + hardcodedVarIntSize;
+                final int totalPacketLength = buffer.writerIndex() - contentIndex + Utils.VARINT_HEADER_SIZE;
 
                 // Update header values
-                Utils.overrideVarInt(buffer, packetLengthIndex, hardcodedVarIntSize, totalPacketLength);
-                Utils.overrideVarInt(buffer, dataLengthIndex, hardcodedVarIntSize, packetSize);
+                Utils.overrideVarIntHeader(buffer, packetLengthIndex, totalPacketLength);
+                Utils.overrideVarIntHeader(buffer, dataLengthIndex, packetSize);
             } else {
                 // Packet too small, just override header values
-                final int totalPacketLength = packetSize + hardcodedVarIntSize;
-                Utils.overrideVarInt(buffer, packetLengthIndex, hardcodedVarIntSize, totalPacketLength);
-                Utils.overrideVarInt(buffer, dataLengthIndex, hardcodedVarIntSize, 0); // -> Uncompressed
+                final int totalPacketLength = packetSize + Utils.VARINT_HEADER_SIZE;
+                Utils.overrideVarIntHeader(buffer, packetLengthIndex, totalPacketLength);
+                Utils.overrideVarIntHeader(buffer, dataLengthIndex, 0); // -> Uncompressed
             }
         } else {
             // No compression
 
             // Write dummy varint
-            final int index = Utils.writeEmptyVarInt(buffer, hardcodedVarIntSize);
+            final int index = Utils.writeEmptyVarIntHeader(buffer);
 
             // Write packet id + payload
             writePacket(buffer, serverPacket);
 
             // Rewrite dummy varint to packet length
             final int afterIndex = buffer.writerIndex();
-            final int packetSize = (afterIndex - index) - hardcodedVarIntSize;
-            Utils.overrideVarInt(buffer, index, hardcodedVarIntSize, packetSize);
+            final int packetSize = (afterIndex - index) - Utils.VARINT_HEADER_SIZE;
+            Utils.overrideVarIntHeader(buffer, index, packetSize);
         }
     }
 
diff --git a/src/main/java/net/minestom/server/utils/Utils.java b/src/main/java/net/minestom/server/utils/Utils.java
index aef87a28b..b83755aa9 100644
--- a/src/main/java/net/minestom/server/utils/Utils.java
+++ b/src/main/java/net/minestom/server/utils/Utils.java
@@ -10,6 +10,9 @@ import java.util.UUID;
 
 public final class Utils {
 
+    // Do NOT modify
+    public static final int VARINT_HEADER_SIZE = 3;
+
     private Utils() {
 
     }
@@ -44,31 +47,26 @@ public final class Utils {
         } while (value != 0);
     }
 
-    public static void overrideVarInt(@NotNull ByteBuf buffer, int startIndex, int length, int value) {
+    public static void overrideVarIntHeader(@NotNull ByteBuf buffer, int startIndex, int value) {
         final int indexCache = buffer.writerIndex();
         buffer.writerIndex(startIndex);
-        writeVarIntBuf(buffer, value);
 
-        final int loopEnd = startIndex + length;
-        for (int i = startIndex; i < loopEnd; i++) {
-            byte b = buffer.getByte(i);
-            boolean last = i == loopEnd - 1;
-            if (last) {
-                b &= ~(1 << 7);
-            } else {
-                b |= 1 << 7;
+        for (int i = 0; i < VARINT_HEADER_SIZE; i++) {
+            byte temp = (byte) (value & 0b01111111);
+            value >>>= 7;
+            if (value != 0 || i != VARINT_HEADER_SIZE - 1) {
+                temp |= 0b10000000;
             }
-            buffer.setByte(i, b);
+
+            buffer.writeByte(temp);
         }
 
         buffer.writerIndex(indexCache);
     }
 
-    public static int writeEmptyVarInt(@NotNull ByteBuf buffer, int length) {
+    public static int writeEmptyVarIntHeader(@NotNull ByteBuf buffer) {
         final int index = buffer.writerIndex();
-        for (int i = 0; i < length; i++) {
-            buffer.writeByte(0);
-        }
+        buffer.writeMedium(0);
         return index;
     }
 
diff --git a/src/main/java/net/minestom/server/utils/binary/BinaryWriter.java b/src/main/java/net/minestom/server/utils/binary/BinaryWriter.java
index 08e1400f2..98f717f1a 100644
--- a/src/main/java/net/minestom/server/utils/binary/BinaryWriter.java
+++ b/src/main/java/net/minestom/server/utils/binary/BinaryWriter.java
@@ -1,6 +1,7 @@
 package net.minestom.server.utils.binary;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.Unpooled;
 import net.kyori.adventure.text.Component;
 import net.minestom.server.MinecraftServer;
@@ -170,9 +171,9 @@ public class BinaryWriter extends OutputStream {
      * @param string the string to write
      */
     public void writeSizedString(@NotNull String string) {
-        final byte[] bytes = string.getBytes(StandardCharsets.UTF_8);
-        writeVarInt(bytes.length);
-        writeBytes(bytes);
+        final int utf8Bytes = ByteBufUtil.utf8Bytes(string);
+        writeVarInt(utf8Bytes);
+        buffer.writeCharSequence(string, StandardCharsets.UTF_8);
     }
 
     /**