diff --git a/models/Todo.js b/models/Todo.js
index 860a870..7b92f3a 100644
--- a/models/Todo.js
+++ b/models/Todo.js
@@ -6,6 +6,8 @@ const TodoSchema = Schema({
   text: {
     type: String,
     required: true,
+    minLength: 1,
+    maxLength: 300,
   },
   list: { type: Schema.Types.ObjectId, ref: 'TodoList', required: true },
   user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
diff --git a/models/TodoList.js b/models/TodoList.js
index 7c5abcd..fa551f6 100644
--- a/models/TodoList.js
+++ b/models/TodoList.js
@@ -6,6 +6,8 @@ const TodoListSchema = Schema({
   name: {
     type: String,
     required: true,
+    minLength: 1,
+    maxLength: 100,
   },
   todos: [{ type: Schema.Types.ObjectId, ref: 'Todo' }],
   user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
diff --git a/models/User.js b/models/User.js
index c8f9ccd..81b2c93 100644
--- a/models/User.js
+++ b/models/User.js
@@ -13,6 +13,8 @@ const UserSchema = Schema({
     required: true,
     unique: true,
     validate: /^\S*$/,
+    minLength: 3,
+    maxLength: 50,
   },
   lists: [{ type: Schema.Types.ObjectId, ref: 'TodoList' }],
   todos: [{ type: Schema.Types.ObjectId, ref: 'Todo' }],