diff --git a/app/assets/javascripts/session_end.js b/app/assets/javascripts/session_end.js
new file mode 100644
index 000000000..5f04bb78e
--- /dev/null
+++ b/app/assets/javascripts/session_end.js
@@ -0,0 +1,68 @@
+/* globals I18n */
+
+(function() {
+  'use strict';
+
+  var originalTitle = '';
+  var expireIn;
+  var expireLimit = 900; // 15min
+  var timeoutID;
+  var expirationUrl = $('meta[name=\'expiration-url\']').attr('content');
+
+  var pad = function(i) {
+    var s = ('0' + Math.floor(i));
+    return s.substring(s.length - 2);
+  };
+
+  var newTimerStr = function(expirationTime) {
+    var m = (expirationTime / 60) % 60;
+    var s = (expirationTime % 60);
+    return [m, s].map(pad).join(':');
+  };
+
+  function getSessionEnd() {
+    if (expirationUrl) {
+      $.get(expirationUrl, function(data) {
+        if (data <= 0) {
+          $('#session-finished').modal();
+        } else if (data <= expireLimit + 1) {
+          expireIn = data;
+          originalTitle = document.title;
+          // eslint-disable-next-line no-use-before-define
+          timeoutID = setTimeout(expirationInTime, 1000);
+        } else {
+          timeoutID = setTimeout(getSessionEnd, (data - expireLimit) * 1000);
+        }
+      });
+    }
+  }
+
+  function expirationInTime() {
+    if (expireIn > 0) {
+      document.title = newTimerStr(expireIn) + ' ' + originalTitle;
+      $('.expiring').text(I18n.t('devise.sessions.expire_modal.session_end_in.header',
+        { time: newTimerStr(expireIn) }));
+      expireIn -= 1;
+      if (!$('#session-expire').hasClass('in')) {
+        $('#session-expire').modal().off('hide.bs.modal').on('hide.bs.modal', function() {
+          if (expireIn > 0) {
+            $.post($('meta[name=\'revive-url\']').attr('content'));
+            document.title = originalTitle;
+            clearTimeout(timeoutID);
+            timeoutID = setTimeout(getSessionEnd, 1000);
+          }
+        });
+      }
+      timeoutID = setTimeout(expirationInTime, 1000);
+    } else {
+      document.title = originalTitle;
+      $('#session-expire').modal('hide');
+      $('#session-finished').modal();
+    }
+  }
+  timeoutID = setTimeout(getSessionEnd, 1000);
+
+  $(document).on('click', '.session-login', function() {
+    window.location.reload();
+  });
+}());
diff --git a/app/assets/stylesheets/session_expired.scss b/app/assets/stylesheets/session_expired.scss
new file mode 100644
index 000000000..adb9df039
--- /dev/null
+++ b/app/assets/stylesheets/session_expired.scss
@@ -0,0 +1,39 @@
+
+// scss-lint:disable NestingDepth ImportantRule
+
+.session-modal {
+  .modal-body {
+    padding-bottom: 0px;
+  }
+
+  ul {
+    list-style-type: none;
+    padding-left: 0;
+
+    li {
+      padding: .25em 0;
+    }
+  }
+
+  a:hover {
+    text-decoration: none;
+  }
+
+  .instruction-session-collapse {
+    cursor: pointer;
+    margin-bottom: .5em;
+    margin-top: 20px;
+
+    .fa-angle-up {
+      margin-left: .5em;
+    }
+
+    &.collapsed {
+
+      .fa-angle-up {
+        @include rotate(-180deg);
+      }
+    }
+  }
+
+}
diff --git a/app/controllers/users/sessions_controller.rb b/app/controllers/users/sessions_controller.rb
index 97a66cd44..d8cab9149 100644
--- a/app/controllers/users/sessions_controller.rb
+++ b/app/controllers/users/sessions_controller.rb
@@ -4,6 +4,7 @@ class Users::SessionsController < Devise::SessionsController
   layout :session_layout
   after_action :after_sign_in, only: %i(create authenticate_with_two_factor)
   before_action :remove_authenticate_mesasge_if_root_path, only: :new
+  prepend_before_action :skip_timeout, only: :expire_in
 
   rescue_from ActionController::InvalidAuthenticityToken do
     redirect_to new_user_session_path
@@ -34,6 +35,16 @@ class Users::SessionsController < Devise::SessionsController
     generate_templates_project
   end
 
+  def expire_in
+    if current_user.remember_created_at.nil?
+      render plain: Devise.timeout_in.to_i - (Time.now.to_i - user_session['last_request_at']).round
+    else
+      render plain: Devise.remember_for - (Time.now.to_i - current_user.remember_created_at.to_i).round
+    end
+  end
+
+  def revive_session; end
+
   def two_factor_recovery
     unless session[:otp_user_id]
       redirect_to new_user_session_path
@@ -92,6 +103,10 @@ class Users::SessionsController < Devise::SessionsController
 
   private
 
+  def skip_timeout
+    request.env['devise.skip_trackable'] = true
+  end
+
   def remove_authenticate_mesasge_if_root_path
     if session[:user_return_to] == root_path && flash[:alert] == I18n.t('devise.failure.unauthenticated')
       flash[:alert] = nil
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index 367e75e27..004cfb215 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -7,9 +7,14 @@
     <meta name="max-file-size" content="<%= Rails.configuration.x.file_max_size_mb %>">
     <meta name="tiny-mce-assets-url" content="<%= tiny_mce_assets_path %>">
     <meta name="highlightjs-url" content="<%= asset_path('highlightjs-github-theme.css') %>">
+    <% if user_signed_in? %>
+      <meta name="expiration-url" content="<%= users_expire_in_path %>">
+      <meta name="revive-url" content="<%= users_revive_session_path %>">
+    <% end %>
     <%= stylesheet_link_tag 'application', media: 'all' %>
     <%= javascript_include_tag 'application' %>
     <%= javascript_pack_tag 'application' %>
+    <%= javascript_include_tag 'session_end' %>
 
 
 
@@ -57,6 +62,8 @@
       <%= render "shared/file_edit_modal.html.erb" %>
       <%= render "shared/marvinjs_modal.html.erb" %>
       <%= render "shared/comments/comments_sidebar.html.erb" %>
+      <%= render "users/sessions/session_expire_modal.html.erb" %>
+      <%= render "users/sessions/session_end_modal.html.erb" %>
     <% end %>
 
     <% if user_signed_in? && flash[:system_notification_modal] && current_user.show_login_system_notification? %>
diff --git a/app/views/users/sessions/_session_end_modal.html.erb b/app/views/users/sessions/_session_end_modal.html.erb
new file mode 100644
index 000000000..d35a1420b
--- /dev/null
+++ b/app/views/users/sessions/_session_end_modal.html.erb
@@ -0,0 +1,39 @@
+<div class="modal session-modal" id="session-finished" tabindex="-1" role="dialog"
+    aria-labelledby="session_expire" data-role="session_expire-modal">
+  <div class="modal-dialog" role="document">
+    <div class="modal-content">
+      <div class="modal-header">
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
+        <h4 class="modal-title"><%= t('devise.sessions.expire_modal.session_ended.header' ) %></h4>
+      </div>
+      <div class="modal-body">
+        <ul>
+          <li><%= t('devise.sessions.expire_modal.session_ended.description') %></li>
+          <li>
+            <a class="collapse-row">
+              <div class="row-title">
+                <div class="instruction-session-collapse collapsed" data-toggle="collapse" href="#InstructionsSectionFinished" aria-expanded="false">
+                  <%= t('devise.sessions.expire_modal.why_see_this') %>
+                  <i class="fas fa-angle-up"></i>
+                </div>
+              </div>
+            </a>
+            <ul class="collapse" id="InstructionsSectionFinished">
+                <li><%= t('devise.sessions.expire_modal.session_end_in.paragraph1') %></li>
+                <li><%= t('devise.sessions.expire_modal.session_end_in.paragraph2') %></li>
+            </ul>
+          </li>
+        </ul>
+      </div>
+
+      <div class="modal-footer">
+        <button type="button" class="btn btn-default" data-dismiss="modal">
+          <%= t('general.close' ) %>
+        </button>
+        <button type="button" class="btn btn-primary session-login">
+          <%= t('devise.sessions.new.submit' ) %>
+        </button>
+      </div>
+    </div>
+  </div>
+</div>
diff --git a/app/views/users/sessions/_session_expire_modal.html.erb b/app/views/users/sessions/_session_expire_modal.html.erb
new file mode 100644
index 000000000..48ea54f35
--- /dev/null
+++ b/app/views/users/sessions/_session_expire_modal.html.erb
@@ -0,0 +1,34 @@
+<div class="modal session-modal" id="session-expire" tabindex="-1" role="dialog"
+    aria-labelledby="session-expire" data-role="session-expire-modal">
+  <div class="modal-dialog" role="document">
+    <div class="modal-content">
+      <div class="modal-header">
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
+        <h4 class="modal-title expiring"></h4>
+      </div>
+      <div class="modal-body">
+        <ul>
+          <li><%= t('devise.sessions.expire_modal.session_end_in.description') %></li>
+          <li>
+            <a class="collapse-row">
+              <div class="row-title">
+                <div class="instruction-session-collapse collapsed" data-toggle="collapse" href="#InstructionsSection" aria-expanded="false">
+                  <%= t('devise.sessions.expire_modal.why_see_this') %>
+                  <i class="fas fa-angle-up"></i>
+                </div>
+              </div>
+            </a>
+            <ul class="collapse" id="InstructionsSection">
+                <li><%= t('devise.sessions.expire_modal.session_end_in.paragraph1') %></li>
+                <li><%= t('devise.sessions.expire_modal.session_end_in.paragraph2') %></li>
+            </ul>
+          </li>
+        </ul>
+      </div>
+
+      <div class="modal-footer">
+        <button type="button" class="btn btn-primary" data-dismiss="modal"><%= t('devise.sessions.expire_modal.session_end_in.revive_session' ) %></button>
+      </div>
+    </div>
+  </div>
+</div>
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index e85038740..48afa6362 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -91,6 +91,7 @@ Rails.application.config.assets.precompile += %w(sidebar_toggle.js)
 Rails.application.config.assets.precompile += %w(reports/reports_datatable.js)
 Rails.application.config.assets.precompile += %w(reports/save_pdf_to_inventory.js)
 Rails.application.config.assets.precompile += %w(reports/content.js)
+Rails.application.config.assets.precompile += %w(session_end.js)
 
 # Libraries needed for Handsontable formulas
 Rails.application.config.assets.precompile += %w(jquery.js)
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 4ed25b874..3882352d7 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -49,6 +49,17 @@ en:
         not_correct_code: "Not correct recovery code"
       create:
         team_name: "%{user}'s projects"
+      expire_modal:
+        why_see_this: 'Why am I seeing this?'
+        session_end_in:
+          header: 'Your session will end in %{time}'
+          description: 'To keep the data you entered into the fields without clicking the Save button, please revive your session and save them.'
+          paragraph1: 'To keep your work secure, SciNote times out sessions after 3 hours of inactivity. '
+          paragraph2: 'To proceed working after the session ends, you’ll have to log in again, starting a new working session.'
+          revive_session: 'Revive my session'
+        session_ended:
+          header: 'To proceed working, please log in again'
+          description: 'If you have any unsaved data, please close this message, copy your text, and paste it back after you log in again.'
     unlocks:
       new:
         head_title: "Resend unlock instructions"
diff --git a/config/routes.rb b/config/routes.rb
index e7c808ff0..a538aff47 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -703,6 +703,8 @@ Rails.application.routes.draw do
       get 'users/sign_up_provider' => 'users/registrations#new_with_provider'
       get 'users/two_factor_recovery' => 'users/sessions#two_factor_recovery'
       get 'users/two_factor_auth' => 'users/sessions#two_factor_auth'
+      get 'users/expire_in' => 'users/sessions#expire_in'
+      post 'users/revive_session' => 'users/sessions#revive_session'
       post 'users/authenticate_with_two_factor' => 'users/sessions#authenticate_with_two_factor'
       post 'users/authenticate_with_recovery_code' => 'users/sessions#authenticate_with_recovery_code'
       post 'users/complete_sign_up_provider' => 'users/registrations#create_with_provider'