diff --git a/bip39-standalone.html b/bip39-standalone.html
index a7d6ce9d..961bedb2 100644
--- a/bip39-standalone.html
+++ b/bip39-standalone.html
@@ -17926,6 +17926,26 @@ <h3 data-translate>Libraries</h3>
   wif: 0xb7,
 };
 
+bitcoin.networks.slimcoin = {
+  bip32: {
+    public: 0xef6adf10,
+    private: 0xef69ea80
+  },
+  pubKeyHash: 0x3f,
+  scriptHash: 0x7d,
+  wif: 0x46,
+};
+
+bitcoin.networks.slimcointn = {
+  bip32: {
+    public: 0x043587CF,
+    private: 0x04358394
+  },
+  pubKeyHash: 0x6f,
+  scriptHash: 0xc4,
+  wif: 0x57,
+};
+
 </script>
         <script>(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.ethUtil = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
 (function (global){
@@ -42839,6 +42859,20 @@ <h3 data-translate>Libraries</h3>
                 DOM.bip44coin.val(1);
             },
         },
+        {
+            name: "Slimcoin",
+            onSelect: function() {
+                network = bitcoin.networks.slimcoin;
+                DOM.bip44coin.val(63);
+            },
+        },
+        {
+            name: "Slimcoin Testnet",
+            onSelect: function() {
+                network = bitcoin.networks.slimcointn;
+                DOM.bip44coin.val(111);
+            },
+        },
         {
             name: "Viacoin",
             onSelect: function() {
diff --git a/readme.md b/readme.md
index ba3a165f..52b6e6fe 100644
--- a/readme.md
+++ b/readme.md
@@ -4,7 +4,9 @@ A tool for converting BIP39 mnemonic phrases to addresses and private keys.
 
 ## Online Version
 
-https://iancoleman.github.io/bip39/
+Upstream demo: https://iancoleman.github.io/bip39/
+
+Slimcoin: TBD
 
 ## Standalone offline version
 
diff --git a/src/js/bitcoinjs-extensions.js b/src/js/bitcoinjs-extensions.js
index ed1bb096..dd5069cf 100644
--- a/src/js/bitcoinjs-extensions.js
+++ b/src/js/bitcoinjs-extensions.js
@@ -75,3 +75,23 @@ bitcoin.networks.peercoin = {
   wif: 0xb7,
 };
 
+bitcoin.networks.slimcoin = {
+  bip32: {
+    public: 0xef6adf10,
+    private: 0xef69ea80
+  },
+  pubKeyHash: 0x3f,
+  scriptHash: 0x7d,
+  wif: 0x46,
+};
+
+bitcoin.networks.slimcointn = {
+  bip32: {
+    public: 0x043587CF,
+    private: 0x04358394
+  },
+  pubKeyHash: 0x6f,
+  scriptHash: 0xc4,
+  wif: 0x57,
+};
+
diff --git a/src/js/index.js b/src/js/index.js
index 8f825f46..8d756379 100644
--- a/src/js/index.js
+++ b/src/js/index.js
@@ -1162,6 +1162,20 @@
                 DOM.bip44coin.val(1);
             },
         },
+        {
+            name: "Slimcoin",
+            onSelect: function() {
+                network = bitcoin.networks.slimcoin;
+                DOM.bip44coin.val(63);
+            },
+        },
+        {
+            name: "Slimcoin Testnet",
+            onSelect: function() {
+                network = bitcoin.networks.slimcointn;
+                DOM.bip44coin.val(111);
+            },
+        },
         {
             name: "Viacoin",
             onSelect: function() {
diff --git a/tests.js b/tests.js
index 49d42c3e..2f2c2f1a 100644
--- a/tests.js
+++ b/tests.js
@@ -723,6 +723,66 @@ page.open(url, function(status) {
 });
 },
 
+// Network can be set to Slimcoin
+function() {
+page.open(url, function(status) {
+    // set the phrase and coin
+    var expected = "SNzPi1CafHFm3WWjRo43aMgiaEEj3ogjww";
+    page.evaluate(function() {
+        $(".phrase").val("abandon abandon ability");
+        $(".phrase").trigger("input");
+        $(".network option[selected]").removeAttr("selected");
+        $(".network option").filter(function() {
+            return $(this).html() == "Slimcoin";
+        }).prop("selected", true);
+        $(".network").trigger("change");
+    });
+    // check the address is generated correctly
+    waitForGenerate(function() {
+        var actual = page.evaluate(function() {
+            return $(".address:first").text();
+        });
+        if (actual != expected) {
+            console.log("Slimcoin address is incorrect");
+            console.log("Expected: " + expected);
+            console.log("Actual: " + actual);
+            fail();
+        }
+        next();
+    });
+});
+},
+
+// Network can be set to Slimcointn
+function() {
+page.open(url, function(status) {
+    // set the phrase and coin
+    var expected = "n3nMgWufTek5QQAr6uwMhg5xbzj8xqc4Dq";
+    page.evaluate(function() {
+        $(".phrase").val("abandon abandon ability");
+        $(".phrase").trigger("input");
+        $(".network option[selected]").removeAttr("selected");
+        $(".network option").filter(function() {
+            return $(this).html() == "Slimcoin Testnet";
+        }).prop("selected", true);
+        $(".network").trigger("change");
+    });
+    // check the address is generated correctly
+    waitForGenerate(function() {
+        var actual = page.evaluate(function() {
+            return $(".address:first").text();
+        });
+        if (actual != expected) {
+            console.log("Slimcoin testnet address is incorrect");
+            console.log("Expected: " + expected);
+            console.log("Actual: " + actual);
+            fail();
+        }
+        next();
+    });
+});
+},
+
 // BIP39 seed is set from phrase
 function() {
 page.open(url, function(status) {