diff --git a/api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/TagStringReader.java b/api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/TagStringReader.java
index baef70a00..960c937c8 100644
--- a/api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/TagStringReader.java
+++ b/api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/TagStringReader.java
@@ -47,6 +47,8 @@ import java.util.stream.LongStream;
 // - Use OpenNBT tags
 // - Small byteArray() optimization
 // - acceptLegacy = true by default
+// - Don't parse value as DoubleTag when possiblyNumeric
+// - Fix trailing comma reading in compounds, lists, and arrays
 final class TagStringReader {
     private static final int MAX_DEPTH = 512;
     private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
@@ -54,7 +56,7 @@ final class TagStringReader {
     private static final long[] EMPTY_LONG_ARRAY = new long[0];
 
     private final CharBuffer buffer;
-    private boolean acceptLegacy = true;
+    private boolean acceptLegacy = true; // Via - always true
     private int depth;
 
     TagStringReader(final CharBuffer buffer) {
@@ -125,11 +127,11 @@ final class TagStringReader {
             return EMPTY_BYTE_ARRAY;
         }
 
-        final IntList bytes = new IntArrayList();
+        final IntList bytes = new IntArrayList(); // Via - no boxing
         while (this.buffer.hasMore()) {
             final CharSequence value = this.buffer.skipWhitespace().takeUntil(Tokens.TYPE_BYTE);
             try {
-                bytes.add(Byte.parseByte(value.toString()));
+                bytes.add(Byte.parseByte(value.toString())); // Via
             } catch (final NumberFormatException ex) {
                 throw this.buffer.makeError("All elements of a byte array must be bytes!");
             }
@@ -137,7 +139,7 @@ final class TagStringReader {
             if (this.separatorOrCompleteWith(Tokens.ARRAY_END)) {
                 final byte[] result = new byte[bytes.size()];
                 for (int i = 0; i < bytes.size(); ++i) {
-                    result[i] = (byte) bytes.getInt(i);
+                    result[i] = (byte) bytes.getInt(i); // Via
                 }
                 return result;
             }
@@ -303,12 +305,8 @@ final class TagStringReader {
         if (possiblyNumeric) {
             try {
                 return new IntTag(Integer.parseInt(built));
-            } catch (final NumberFormatException ex) {
-                try {
-                    return new DoubleTag(Double.parseDouble(built));
-                } catch (final NumberFormatException ex2) {
-                    // ignore
-                }
+            } catch (final NumberFormatException ignored) {
+                // Via - don't try to parse as DoubleTag here
             }
         }
 
@@ -326,7 +324,7 @@ final class TagStringReader {
             return true;
         }
         this.buffer.expect(Tokens.VALUE_SEPARATOR);
-        return false;
+        return this.buffer.takeIf(endCharacter); // Via - trailing commas are allowed
     }
 
     /**
diff --git a/common/src/test/java/com/viaversion/viaversion/common/nbt/NBTTagTest.java b/common/src/test/java/com/viaversion/viaversion/common/nbt/NBTTagTest.java
new file mode 100644
index 000000000..f2a3a143e
--- /dev/null
+++ b/common/src/test/java/com/viaversion/viaversion/common/nbt/NBTTagTest.java
@@ -0,0 +1,44 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.common.nbt;
+
+import com.github.steveice10.opennbt.tag.builtin.StringTag;
+import com.viaversion.viaversion.api.minecraft.nbt.BinaryTagIO;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+public class NBTTagTest {
+
+    @Test
+    void test() throws IOException {
+        BinaryTagIO.readString("{id:test,test:1}");
+        BinaryTagIO.readString("{id:test,test:1,}");
+
+        BinaryTagIO.readString("{id:[1,2,3,]}");
+
+        BinaryTagIO.readString("{id:[I;1,2,3]}");
+        BinaryTagIO.readString("{id:[I;1,2,3,]}");
+
+        Assertions.assertTrue(BinaryTagIO.readString("{id:9000b,num:2147483649}").get("num") instanceof StringTag);
+
+        //TODO fix legacy
+        // BinaryTagIO.readString("{id:minecraft:stone}");
+    }
+}