diff --git a/src/main/java/com/annimon/ownlang/modules/base64/base64.java b/src/main/java/com/annimon/ownlang/modules/base64/base64.java
new file mode 100644
index 0000000..328ffa9
--- /dev/null
+++ b/src/main/java/com/annimon/ownlang/modules/base64/base64.java
@@ -0,0 +1,74 @@
+package com.annimon.ownlang.modules.base64;
+
+import com.annimon.ownlang.lib.*;
+import com.annimon.ownlang.modules.Module;
+import java.io.UnsupportedEncodingException;
+import java.util.Base64;
+
+public class base64 implements Module {
+
+    private static final int TYPE_URL_SAFE = 8;
+
+    public static void initConstants() {
+        Variables.define("BASE64_URL_SAFE", NumberValue.of(TYPE_URL_SAFE));
+    }
+
+    @Override
+    public void init() {
+        initConstants();
+        Functions.set("base64encode", this::base64encode);
+        Functions.set("base64decode", this::base64decode);
+        Functions.set("base64encodeToString", this::base64encodeToString);
+    }
+
+    private Value base64encode(Value... args) {
+        Arguments.checkOrOr(1, 2, args.length);
+        return ArrayValue.of(getEncoder(args).encode(getInputToEncode(args)));
+    }
+
+    private Value base64encodeToString(Value... args) {
+        Arguments.checkOrOr(1, 2, args.length);
+        return new StringValue(getEncoder(args).encodeToString(getInputToEncode(args)));
+    }
+
+    private Value base64decode(Value... args) {
+        Arguments.checkOrOr(1, 2, args.length);
+        final Base64.Decoder decoder = getDecoder(args);
+        final byte[] result;
+        if (args[0].type() == Types.ARRAY) {
+            result = decoder.decode(ValueUtils.toByteArray((ArrayValue) args[0]));
+        } else {
+            result = decoder.decode(args[0].asString());
+        }
+        return ArrayValue.of(result);
+    }
+
+
+    private byte[] getInputToEncode(Value[] args) {
+        byte[] input;
+        if (args[0].type() == Types.ARRAY) {
+            input = ValueUtils.toByteArray((ArrayValue) args[0]);
+        } else {
+            try {
+                input = args[0].asString().getBytes("UTF-8");
+            } catch (UnsupportedEncodingException ex) {
+                input = args[0].asString().getBytes();
+            }
+        }
+        return input;
+    }
+
+    private Base64.Encoder getEncoder(Value[] args) {
+        if (args.length == 2 && args[1].asInt() == TYPE_URL_SAFE) {
+            return Base64.getUrlEncoder();
+        }
+        return Base64.getEncoder();
+    }
+
+    private Base64.Decoder getDecoder(Value[] args) {
+        if (args.length == 2 && args[1].asInt() == TYPE_URL_SAFE) {
+            return Base64.getUrlDecoder();
+        }
+        return Base64.getDecoder();
+    }
+}
diff --git a/src/test/resources/modules/base64/base64.own b/src/test/resources/modules/base64/base64.own
new file mode 100644
index 0000000..841dfdd
--- /dev/null
+++ b/src/test/resources/modules/base64/base64.own
@@ -0,0 +1,31 @@
+use "base64"
+use "functional"
+use "types"
+
+base64Example = [0x42, 0x61, 0x73, 0x65, 0x36, 0x34, 0x20, 0x45, 0x78, 0x61, 0x6D, 0x70, 0x6C, 0x65]
+base64Example_enc = [0x51, 0x6D, 0x46, 0x7A, 0x5A, 0x54, 0x59, 0x30,
+                     0x49, 0x45, 0x56, 0x34, 0x59, 0x57, 0x31, 0x77,
+                     0x62, 0x47, 0x55, 0x3D]
+unicode = map([0xD0, 0xAE, 0xD0, 0xBD, 0xD0, 0xB8, 0xD0, 0xBA, 0xD0, 0xBE, 0xD0, 0xB4], ::byte)
+unicode_enc = [0x30, 0x4B, 0x37, 0x51, 0x76, 0x64, 0x43, 0x34, 0x30, 0x4C, 0x72, 0x51, 0x76, 0x74, 0x43, 0x30]
+
+def testBase64Encode() {
+  assertEquals(base64Example_enc, base64encode(base64Example))
+  assertEquals(base64Example_enc, base64encode("Base64 Example"))
+  assertEquals(unicode_enc, base64encode(unicode))
+  assertEquals(unicode_enc, base64encode("Юникод"))
+}
+
+def testBase64EncodeToString() {
+  assertEquals("QmFzZTY0IEV4YW1wbGU=", base64encodeToString(base64Example))
+  assertEquals("QmFzZTY0IEV4YW1wbGU=", base64encodeToString("Base64 Example"))
+  assertEquals("0K7QvdC40LrQvtC0", base64encodeToString(unicode))
+  assertEquals("0K7QvdC40LrQvtC0", base64encodeToString("Юникод"))
+}
+
+def testBase64Decode() {
+  assertEquals(base64Example, base64decode("QmFzZTY0IEV4YW1wbGU="))
+  assertEquals(base64Example, base64decode(base64Example_enc))
+  assertEquals(unicode, base64decode("0K7QvdC40LrQvtC0"))
+  assertEquals(unicode, base64decode(unicode_enc))
+}
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