diff --git a/lib/todo-app.js b/lib/todo-app.js
index 2b9c956..6782ae6 100644
--- a/lib/todo-app.js
+++ b/lib/todo-app.js
@@ -5,10 +5,25 @@ if (typeof require !== 'undefined' && this.window !== this) {
     route, section, span, strong, text, ul } = require('./elmish.js');
 }
 
-var initial_model = {
+function set_search_state(model, value) {
+  Object.defineProperty(model, 'search', {
+    value: value || '',
+    writable: true,
+    configurable: true,
+    enumerable: false
+  });
+  return model;
+}
+
+function clone_model(model) {
+  var cloned = JSON.parse(JSON.stringify(model));
+  return set_search_state(cloned, model && model.search);
+}
+
+var initial_model = set_search_state({
   todos: [],
   hash: "#/"
-}
+}, "")
 
 /**
  * `update` transforms the `model` based on the `action`.
@@ -18,7 +33,7 @@ var initial_model = {
  * @return {Object} new_model - the transformed model.
  */
 function update(action, model, data) {
-  var new_model = JSON.parse(JSON.stringify(model)) // "clone" the model
+  var new_model = clone_model(model) // "clone" the model
 
   switch(action) {
     case 'ADD':
@@ -103,6 +118,9 @@ function update(action, model, data) {
       new_model.hash = // (window && window.location && window.location.hash) ?
         window.location.hash // : '#/';
       break;
+    case 'SEARCH':
+      set_search_state(new_model, data);
+      break;
     default: // if action unrecognised or undefined,
       return model; // return model unmodified
   }   // see: https://softwareengineering.stackexchange.com/a/201786/211301
@@ -187,6 +205,12 @@ function render_main (model, signal) {
               return item;
           }
         })
+        .filter(function (item) {
+          if (!model.search || model.search.length === 0) {
+            return true;
+          }
+          return item.title.toLowerCase().indexOf(model.search.toLowerCase()) !== -1;
+        })
         .map(function (item) {
           return render_item(item, model, signal)
         }) : null
@@ -208,27 +232,43 @@ function render_main (model, signal) {
  */
 function render_footer (model, signal) {
 
-  // count how many "active" (not yet done) items by filtering done === false:
-  var done = (model.todos && model.todos.length > 0) ?
+  var filtered_todos = (model.todos && model.todos.length > 0) ?
+    model.todos
+    .filter(function (item) {
+      switch(model.hash) {
+        case '#/active':
+          return !item.done;
+        case '#/completed':
+          return item.done;
+        default:
+          return item;
+      }
+    })
+    .filter(function (item) {
+      if (!model.search || model.search.length === 0) {
+        return true;
+      }
+      return item.title.toLowerCase().indexOf(model.search.toLowerCase()) !== -1;
+    }) : [];
+
+  var total_done = (model.todos && model.todos.length > 0) ?
     model.todos.filter( function (i) { return i.done; }).length : 0;
-  var count = (model.todos && model.todos.length > 0) ?
+  var total_count = (model.todos && model.todos.length > 0) ?
     model.todos.filter( function (i) { return !i.done; }).length : 0;
 
-  // Requirement #1 - No Todos, should hide #footer and #main
-  var display = (count > 0 || done > 0) ? "block" : "none";
+  var display = (total_count > 0 || total_done > 0) ? "block" : "none";
+
+  var filtered_done = filtered_todos.filter(function (i) { return i.done; }).length;
+  var filtered_count = filtered_todos.filter(function (i) { return !i.done; }).length;
 
-  // number of completed items:
-  var done = (model.todos && model.todos.length > 0) ?
-    (model.todos.length - count) : 0;
-  var display_clear =  (done > 0) ? "block;" : "none;";
+  var display_clear = (filtered_done > 0) ? "block;" : "none;";
 
-  // pluarisation of number of items:
-  var left = (" item" + ( count > 1 || count === 0 ? 's' : '') + " left");
+  var left = (" item" + ( filtered_count > 1 || filtered_count === 0 ? 's' : '') + " left");
 
   return (
     footer(["class=footer", "id=footer", "style=display:" + display], [
       span(["class=todo-count", "id=count"], [
-        strong(count),
+        strong(filtered_count),
         text(left)
       ]),
       ul(["class=filters"], [
@@ -260,7 +300,7 @@ function render_footer (model, signal) {
         [
           text("Clear completed ["),
           span(["id=completed-count"], [
-            text(done)
+            text(filtered_done)
           ]),
           text("]")
         ]
@@ -293,7 +333,13 @@ function view (model, signal) {
           "class=new-todo",
           "placeholder=What needs to be done?",
           "autofocus"
-        ], []) // <input> is "self-closing"
+        ], []), // <input> is "self-closing"
+        input([
+          "id=search-todo",
+          "class=search-todo",
+          "placeholder=Search todos...",
+          model.search ? "value=" + model.search : ""
+        ], []) // search input
       ]), // </header>
       render_main(model, signal),
       render_footer(model, signal)
@@ -311,6 +357,8 @@ function subscriptions (signal) {
 	var ENTER_KEY = 13; // add a new todo item when [Enter] key is pressed
 	var ESCAPE_KEY = 27; // used for "escaping" when editing a Todo item
 
+  signal('SEARCH', '')();
+
   document.addEventListener('keyup', function handler (e) {
     // console.log('e.keyCode:', e.keyCode, '| key:', e.key);
 
@@ -334,6 +382,12 @@ function subscriptions (signal) {
     }
   });
 
+  document.addEventListener('input', function handler (e) {
+    if (e.target && e.target.id === 'search-todo') {
+      signal('SEARCH', e.target.value)();
+    }
+  });
+
   window.onhashchange = function route () {
     signal('ROUTE')();
   }
diff --git a/test/todo-app.test.js b/test/todo-app.test.js
index 5ec459c..7ea4f46 100644
--- a/test/todo-app.test.js
+++ b/test/todo-app.test.js
@@ -11,6 +11,7 @@ test('`model` (Object) has desired keys', function (t) {
   const keys = Object.keys(app.model);
   t.deepEqual(keys, ['todos', 'hash'], "`todos` and `hash` keys are present.");
   t.true(Array.isArray(app.model.todos), "model.todos is an Array")
+  t.equal(app.model.search, '', "model.search defaults to empty string");
   t.end();
 });
 
@@ -678,3 +679,203 @@ test('9. Routing > should allow me to display active/completed/all items',
   t.end();
 });
 
+test('10. Search > model should have search field', function (t) {
+  t.equal(typeof app.model.search, 'string', "`search` field is available on model.");
+  t.equal(app.model.search, '', "initial search value is empty string.");
+  t.end();
+});
+
+test('10.1 Search > update SEARCH action should set search field', function (t) {
+  const model = { todos: [], hash: '#/' };
+  t.equal(model.search, undefined, "search is not persisted on plain stored models.");
+  
+  const updated_model = app.update('SEARCH', model, "test");
+  t.equal(updated_model.search, "test", "search field is updated to 'test'.");
+  
+  const cleared_model = app.update('SEARCH', updated_model, "");
+  t.equal(cleared_model.search, "", "search field is cleared.");
+  
+  t.end();
+});
+
+test('10.2 Search > render_main should filter todos by search term', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy milk", done: false },
+      { id: 1, title: "Buy eggs", done: false },
+      { id: 2, title: "Go to gym", done: false }
+    ],
+    hash: '#/',
+    search: ""
+  };
+  
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 3, "no search: 3 items");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "buy";
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 2, "search 'buy': 2 items");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "gym";
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 1, "search 'gym': 1 item");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "nonexistent";
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 0, "search 'nonexistent': 0 items");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.3 Search > search should be case-insensitive', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy Milk", done: false },
+      { id: 1, title: "buy eggs", done: false }
+    ],
+    hash: '#/',
+    search: ""
+  };
+  
+  model.search = "BUY";
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 2, "search 'BUY' matches both items");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "MILK";
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 1, "search 'MILK' matches 'Buy Milk'");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.4 Search > search should work with route filtering (All + search)', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy milk", done: false },
+      { id: 1, title: "Buy eggs", done: true },
+      { id: 2, title: "Go to gym", done: false }
+    ],
+    hash: '#/',
+    search: "buy"
+  };
+  
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 2, "All + search 'buy': 2 items");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.5 Search > search should work with route filtering (Active + search)', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy milk", done: false },
+      { id: 1, title: "Buy eggs", done: true },
+      { id: 2, title: "Go to gym", done: false }
+    ],
+    hash: '#/active',
+    search: "buy"
+  };
+  
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 1, "Active + search 'buy': 1 item (only 'Buy milk' is active)");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.6 Search > search should work with route filtering (Completed + search)', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy milk", done: false },
+      { id: 1, title: "Buy eggs", done: true },
+      { id: 2, title: "Go to gym", done: false }
+    ],
+    hash: '#/completed',
+    search: "buy"
+  };
+  
+  document.getElementById(id).appendChild(app.render_main(model, mock_signal));
+  t.equal(document.querySelectorAll('.view').length, 1, "Completed + search 'buy': 1 item (only 'Buy eggs' is completed)");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.7 Search > render_footer count should reflect filtered results', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy milk", done: false },
+      { id: 1, title: "Buy eggs", done: true },
+      { id: 2, title: "Go to gym", done: false }
+    ],
+    hash: '#/',
+    search: ""
+  };
+  
+  document.getElementById(id).appendChild(app.render_footer(model));
+  let count = parseInt(document.getElementById('count').textContent, 10);
+  t.equal(count, 2, "no search: 2 items left");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "buy";
+  document.getElementById(id).appendChild(app.render_footer(model));
+  count = parseInt(document.getElementById('count').textContent, 10);
+  t.equal(count, 1, "search 'buy': 1 item left ('Buy milk' is active)");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.8 Search > render_footer clear completed should reflect filtered results', function (t) {
+  const model = {
+    todos: [
+      { id: 0, title: "Buy milk", done: false },
+      { id: 1, title: "Buy eggs", done: true },
+      { id: 2, title: "Go to gym", done: true }
+    ],
+    hash: '#/',
+    search: ""
+  };
+  
+  document.getElementById(id).appendChild(app.render_footer(model));
+  let completed_count = parseInt(document.getElementById('completed-count').textContent, 10);
+  t.equal(completed_count, 2, "no search: 2 completed items");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "gym";
+  document.getElementById(id).appendChild(app.render_footer(model));
+  completed_count = parseInt(document.getElementById('completed-count').textContent, 10);
+  t.equal(completed_count, 1, "search 'gym': 1 completed item in results");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});
+
+test('10.9 Search > view should render search input', function (t) {
+  const model = {
+    todos: [],
+    hash: '#/',
+    search: ""
+  };
+  
+  document.getElementById(id).appendChild(app.view(model));
+  const search_input = document.getElementById('search-todo');
+  t.notEqual(search_input, null, "search input exists");
+  t.equal(search_input.getAttribute('placeholder'), 'Search todos...', "search input has correct placeholder");
+  elmish.empty(document.getElementById(id));
+  
+  model.search = "test";
+  document.getElementById(id).appendChild(app.view(model));
+  const search_input_with_value = document.getElementById('search-todo');
+  t.equal(search_input_with_value.value, 'test', "search input displays search value");
+  elmish.empty(document.getElementById(id));
+  
+  t.end();
+});