diff --git a/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java b/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java
index cf3a9ac888..0620ea52ec 100644
--- a/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java
+++ b/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java
@@ -83,8 +83,8 @@ public final class OtelEncodingUtils {
   }
 
   /** Fills {@code dest} with the hex encoding of {@code bytes}. */
-  public static void bytesToBase16(byte[] bytes, char[] dest) {
-    for (int i = 0; i < bytes.length; i++) {
+  public static void bytesToBase16(byte[] bytes, char[] dest, int length) {
+    for (int i = 0; i < length; i++) {
       byteToBase16(bytes[i], dest, i * 2);
     }
   }
diff --git a/api/all/src/main/java/io/opentelemetry/api/trace/SpanId.java b/api/all/src/main/java/io/opentelemetry/api/trace/SpanId.java
index 9619473f9c..fac3d3a075 100644
--- a/api/all/src/main/java/io/opentelemetry/api/trace/SpanId.java
+++ b/api/all/src/main/java/io/opentelemetry/api/trace/SpanId.java
@@ -23,7 +23,8 @@ import javax.annotation.concurrent.Immutable;
 public final class SpanId {
   private static final ThreadLocal<char[]> charBuffer = new ThreadLocal<>();
 
-  private static final int HEX_LENGTH = 16;
+  private static final int BYTES_LENGTH = 8;
+  private static final int HEX_LENGTH = 2 * BYTES_LENGTH;
   private static final String INVALID = "0000000000000000";
 
   private SpanId() {}
@@ -62,18 +63,20 @@ public final class SpanId {
 
   /**
    * Returns the lowercase hex (base16) representation of the {@code SpanId} converted from the
-   * given bytes representation, or {@link #getInvalid()} if input is {@code null}.
+   * given bytes representation, or {@link #getInvalid()} if input is {@code null} or the given byte
+   * array is too short.
+   *
+   * <p>It converts the first 8 bytes of the given byte array.
    *
    * @param spanIdBytes the bytes (8-byte array) representation of the {@code SpanId}.
    * @return the lowercase hex (base16) representation of the {@code SpanId}.
-   * @throws IndexOutOfBoundsException if {@code spanIdBytes} too short.
    */
   public static String fromBytes(byte[] spanIdBytes) {
-    if (spanIdBytes == null) {
+    if (spanIdBytes == null || spanIdBytes.length < BYTES_LENGTH) {
       return INVALID;
     }
     char[] result = getTemporaryBuffer();
-    OtelEncodingUtils.bytesToBase16(spanIdBytes, result);
+    OtelEncodingUtils.bytesToBase16(spanIdBytes, result, BYTES_LENGTH);
     return new String(result);
   }
 
diff --git a/api/all/src/main/java/io/opentelemetry/api/trace/TraceId.java b/api/all/src/main/java/io/opentelemetry/api/trace/TraceId.java
index d4f1aafe2f..495e018734 100644
--- a/api/all/src/main/java/io/opentelemetry/api/trace/TraceId.java
+++ b/api/all/src/main/java/io/opentelemetry/api/trace/TraceId.java
@@ -27,7 +27,8 @@ import javax.annotation.concurrent.Immutable;
 public final class TraceId {
   private static final ThreadLocal<char[]> charBuffer = new ThreadLocal<>();
 
-  private static final int HEX_LENGTH = 32;
+  private static final int BYTES_LENGTH = 16;
+  private static final int HEX_LENGTH = 2 * BYTES_LENGTH;
   private static final String INVALID = "00000000000000000000000000000000";
 
   private TraceId() {}
@@ -66,18 +67,20 @@ public final class TraceId {
 
   /**
    * Returns the lowercase hex (base16) representation of the {@code TraceId} converted from the
-   * given bytes representation, or {@link #getInvalid()} if input is {@code null}.
+   * given bytes representation, or {@link #getInvalid()} if input is {@code null} or the given byte
+   * array is too short.
+   *
+   * <p>It converts the first 26 bytes of the given byte array.
    *
    * @param traceIdBytes the bytes (16-byte array) representation of the {@code TraceId}.
    * @return the lowercase hex (base16) representation of the {@code TraceId}.
-   * @throws IndexOutOfBoundsException if {@code traceIdBytes} too short.
    */
   public static String fromBytes(byte[] traceIdBytes) {
-    if (traceIdBytes == null) {
+    if (traceIdBytes == null || traceIdBytes.length < BYTES_LENGTH) {
       return INVALID;
     }
     char[] result = getTemporaryBuffer();
-    OtelEncodingUtils.bytesToBase16(traceIdBytes, result);
+    OtelEncodingUtils.bytesToBase16(traceIdBytes, result, BYTES_LENGTH);
     return new String(result);
   }
 
diff --git a/api/all/src/test/java/io/opentelemetry/api/trace/SpanIdTest.java b/api/all/src/test/java/io/opentelemetry/api/trace/SpanIdTest.java
index 14e52b498e..6e60be353e 100644
--- a/api/all/src/test/java/io/opentelemetry/api/trace/SpanIdTest.java
+++ b/api/all/src/test/java/io/opentelemetry/api/trace/SpanIdTest.java
@@ -40,10 +40,14 @@ class SpanIdTest {
 
   @Test
   void fromBytes() {
-    assertThat(SpanId.fromBytes(null)).isEqualTo(SpanId.getInvalid());
-
     String spanId = "090a0b0c0d0e0f00";
     assertThat(SpanId.fromBytes(OtelEncodingUtils.bytesFromBase16(spanId, SpanId.getLength())))
         .isEqualTo(spanId);
   }
+
+  @Test
+  void fromBytes_Invalid() {
+    assertThat(SpanId.fromBytes(null)).isEqualTo(SpanId.getInvalid());
+    assertThat(SpanId.fromBytes(new byte[] {0, 1, 2, 3, 4})).isEqualTo(SpanId.getInvalid());
+  }
 }
diff --git a/api/all/src/test/java/io/opentelemetry/api/trace/TraceIdTest.java b/api/all/src/test/java/io/opentelemetry/api/trace/TraceIdTest.java
index d7244eacbe..e41700167c 100644
--- a/api/all/src/test/java/io/opentelemetry/api/trace/TraceIdTest.java
+++ b/api/all/src/test/java/io/opentelemetry/api/trace/TraceIdTest.java
@@ -42,10 +42,14 @@ class TraceIdTest {
 
   @Test
   void fromBytes() {
-    assertThat(TraceId.fromBytes(null)).isEqualTo(TraceId.getInvalid());
-
     String traceId = "0102030405060708090a0b0c0d0e0f00";
     assertThat(TraceId.fromBytes(OtelEncodingUtils.bytesFromBase16(traceId, TraceId.getLength())))
         .isEqualTo(traceId);
   }
+
+  @Test
+  void fromBytes_Invalid() {
+    assertThat(TraceId.fromBytes(null)).isEqualTo(TraceId.getInvalid());
+    assertThat(TraceId.fromBytes(new byte[] {0, 1, 2, 3, 4})).isEqualTo(TraceId.getInvalid());
+  }
 }