diff --git a/include/indicators/details/stream_helper.hpp b/include/indicators/details/stream_helper.hpp
index 5796225..935599e 100644
--- a/include/indicators/details/stream_helper.hpp
+++ b/include/indicators/details/stream_helper.hpp
@@ -155,5 +155,31 @@ private:
   std::string remainder;
 };
 
+class IndeterminateProgressScaleWriter {
+public:
+  IndeterminateProgressScaleWriter(std::ostream &os, size_t bar_width, const std::string &fill,
+                      const std::string &lead)
+      : os(os), bar_width(bar_width), fill(fill), lead(lead) {}
+
+  std::ostream &write(float progress) {
+    auto pos = static_cast<size_t>(progress * bar_width / 100.0);
+    for (size_t i = 0; i < bar_width; ++i) {
+      if (i < pos)
+        os << fill;
+      else if (i == pos)
+        os << lead;
+      else
+        os << remainder;
+    }
+    return os;
+  }
+
+private:
+  std::ostream &os;
+  size_t bar_width = 0;
+  std::string fill;
+  std::string lead;
+};
+
 } // namespace details
 } // namespace indicators
diff --git a/include/indicators/indeterminate_progress_bar.hpp b/include/indicators/indeterminate_progress_bar.hpp
new file mode 100644
index 0000000..8054220
--- /dev/null
+++ b/include/indicators/indeterminate_progress_bar.hpp
@@ -0,0 +1,254 @@
+/*
+Activity Indicators for Modern C++
+https://github.com/p-ranav/indicators
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2019 Pranav Srinivas Kumar <pranav.srinivas.kumar@gmail.com>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+#pragma once
+
+#include <indicators/details/stream_helper.hpp>
+
+#include <algorithm>
+#include <atomic>
+#include <chrono>
+#include <cmath>
+#include <indicators/color.hpp>
+#include <indicators/setting.hpp>
+#include <iomanip>
+#include <iostream>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <tuple>
+#include <type_traits>
+
+namespace indicators {
+
+class IndeterminateProgressBar {
+  using Settings =
+      std::tuple<option::BarWidth, option::PrefixText, option::PostfixText, option::Start,
+                 option::End, option::Fill, option::Lead,
+                 option::MaxPostfixTextLen, option::Completed,
+                 option::ShowElapsedTime, option::ShowRemainingTime, option::SavedStartTime,
+                 option::ForegroundColor, option::FontStyles>;
+
+public:
+  template <typename... Args,
+            typename std::enable_if<details::are_settings_from_tuple<
+                                        Settings, typename std::decay<Args>::type...>::value,
+                                    void *>::type = nullptr>
+  explicit IndeterminateProgressBar(Args &&... args)
+      : settings_(details::get<details::ProgressBarOption::bar_width>(option::BarWidth{100},
+                                                                      std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::prefix_text>(
+                      option::PrefixText{}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::postfix_text>(
+                      option::PostfixText{}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::start>(option::Start{"["},
+                                                                  std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::end>(option::End{"]"},
+                                                                std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::fill>(option::Fill{"="},
+                                                                 std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::lead>(option::Lead{">"},
+                                                                 std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::max_postfix_text_len>(
+                      option::MaxPostfixTextLen{0}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::completed>(option::Completed{false},
+                                                                      std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::show_elapsed_time>(
+                      option::ShowElapsedTime{false}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::show_remaining_time>(
+                      option::ShowRemainingTime{false}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::saved_start_time>(
+                      option::SavedStartTime{false}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::foreground_color>(
+                      option::ForegroundColor{Color::unspecified}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::font_styles>(
+                      option::FontStyles{std::vector<FontStyle>{}}, std::forward<Args>(args)...),
+                  details::get<details::ProgressBarOption::max_progress>(
+                      option::MaxProgress{100}, std::forward<Args>(args)...)) {}
+
+  template <typename T, details::ProgressBarOption id>
+  void set_option(details::Setting<T, id> &&setting) {
+    static_assert(!std::is_same<T, typename std::decay<decltype(details::get_value<id>(
+                                       std::declval<Settings>()))>::type>::value,
+                  "Setting has wrong type!");
+    std::lock_guard<std::mutex> lock(mutex_);
+    get_value<id>() = std::move(setting).value;
+  }
+
+  template <typename T, details::ProgressBarOption id>
+  void set_option(const details::Setting<T, id> &setting) {
+    static_assert(!std::is_same<T, typename std::decay<decltype(details::get_value<id>(
+                                       std::declval<Settings>()))>::type>::value,
+                  "Setting has wrong type!");
+    std::lock_guard<std::mutex> lock(mutex_);
+    get_value<id>() = setting.value;
+  }
+
+  void set_option(
+      const details::Setting<std::string, details::ProgressBarOption::postfix_text> &setting) {
+    std::lock_guard<std::mutex> lock(mutex_);
+    get_value<details::ProgressBarOption::postfix_text>() = setting.value;
+    if (setting.value.length() > get_value<details::ProgressBarOption::max_postfix_text_len>()) {
+      get_value<details::ProgressBarOption::max_postfix_text_len>() = setting.value.length();
+    }
+  }
+
+  void
+  set_option(details::Setting<std::string, details::ProgressBarOption::postfix_text> &&setting) {
+    std::lock_guard<std::mutex> lock(mutex_);
+    get_value<details::ProgressBarOption::postfix_text>() = std::move(setting).value;
+    auto &new_value = get_value<details::ProgressBarOption::postfix_text>();
+    if (new_value.length() > get_value<details::ProgressBarOption::max_postfix_text_len>()) {
+      get_value<details::ProgressBarOption::max_postfix_text_len>() = new_value.length();
+    }
+  }
+
+  void tick() {
+    {
+      std::lock_guard<std::mutex> lock{mutex_};
+      progress_ += 1;
+    }
+    save_start_time();
+    print_progress();
+  }
+
+  void mark_as_completed() {
+    get_value<details::ProgressBarOption::completed>() = true;
+    print_progress();
+  }
+
+private:
+  template <details::ProgressBarOption id>
+  auto get_value() -> decltype((details::get_value<id>(std::declval<Settings &>()).value)) {
+    return details::get_value<id>(settings_).value;
+  }
+
+  template <details::ProgressBarOption id>
+  auto get_value() const
+      -> decltype((details::get_value<id>(std::declval<const Settings &>()).value)) {
+    return details::get_value<id>(settings_).value;
+  }
+
+  size_t progress_{0};
+  Settings settings_;
+  std::chrono::nanoseconds elapsed_;
+  std::chrono::time_point<std::chrono::high_resolution_clock> start_time_point_;
+  std::mutex mutex_;
+
+  template <typename Indicator, size_t count> friend class MultiProgress;
+  template <typename Indicator> friend class DynamicProgress;
+  std::atomic<bool> multi_progress_mode_{false};
+
+  void save_start_time() {
+    auto &show_elapsed_time = get_value<details::ProgressBarOption::show_elapsed_time>();
+    auto &saved_start_time = get_value<details::ProgressBarOption::saved_start_time>();
+    auto &show_remaining_time = get_value<details::ProgressBarOption::show_remaining_time>();
+    if ((show_elapsed_time || show_remaining_time) && !saved_start_time) {
+      start_time_point_ = std::chrono::high_resolution_clock::now();
+      saved_start_time = true;
+    }
+  }
+
+public:
+  void print_progress(bool from_multi_progress = false) {
+    std::lock_guard<std::mutex> lock{mutex_};
+    if (multi_progress_mode_ && !from_multi_progress) {
+      return;
+    }
+    auto now = std::chrono::high_resolution_clock::now();
+    if (!get_value<details::ProgressBarOption::completed>())
+      elapsed_ = std::chrono::duration_cast<std::chrono::nanoseconds>(now - start_time_point_);
+
+    if (get_value<details::ProgressBarOption::foreground_color>() != Color::unspecified)
+      details::set_stream_color(std::cout, get_value<details::ProgressBarOption::foreground_color>());
+
+    for (auto &style : get_value<details::ProgressBarOption::font_styles>())
+      details::set_font_style(std::cout, style);
+
+    std::cout << get_value<details::ProgressBarOption::prefix_text>();
+
+    std::cout << get_value<details::ProgressBarOption::start>();
+
+    details::ProgressScaleWriter writer{std::cout,
+                                        get_value<details::ProgressBarOption::bar_width>(),
+                                        get_value<details::ProgressBarOption::fill>(),
+                                        get_value<details::ProgressBarOption::lead>(),
+                                        get_value<details::ProgressBarOption::remainder>()};
+    writer.write(double(progress_) / double(max_progress) * 100.0f);
+
+    std::cout << get_value<details::ProgressBarOption::end>();
+
+    if (get_value<details::ProgressBarOption::show_percentage>()) {
+      std::cout << " " << std::min(static_cast<size_t>(static_cast<float>(progress_) / max_progress * 100), size_t(100)) << "%";
+    }
+
+    auto &saved_start_time = get_value<details::ProgressBarOption::saved_start_time>();
+
+    if (get_value<details::ProgressBarOption::show_elapsed_time>()) {
+      std::cout << " [";
+      if (saved_start_time)
+        details::write_duration(std::cout, elapsed_);
+      else
+        std::cout << "00:00s";
+    }
+
+    if (get_value<details::ProgressBarOption::show_remaining_time>()) {
+      if (get_value<details::ProgressBarOption::show_elapsed_time>())
+        std::cout << "<";
+      else
+        std::cout << " [";
+
+      if (saved_start_time) {
+        auto eta = std::chrono::nanoseconds(
+            progress_ > 0 ? static_cast<long long>(elapsed_.count() * max_progress / progress_) : 0);
+        auto remaining = eta > elapsed_ ? (eta - elapsed_) : (elapsed_ - eta);
+        details::write_duration(std::cout, remaining);
+      } else {
+        std::cout << "00:00s";
+      }
+
+      std::cout << "]";
+    } else {
+      if (get_value<details::ProgressBarOption::show_elapsed_time>())
+        std::cout << "]";
+    }
+
+    if (get_value<details::ProgressBarOption::max_postfix_text_len>() == 0)
+      get_value<details::ProgressBarOption::max_postfix_text_len>() = 10;
+    std::cout << " " << get_value<details::ProgressBarOption::postfix_text>()
+              << std::string(get_value<details::ProgressBarOption::max_postfix_text_len>(), ' ')
+              << "\r";
+    std::cout.flush();
+    if (progress_ >= max_progress) {
+      get_value<details::ProgressBarOption::completed>() = true;
+    }
+    if (get_value<details::ProgressBarOption::completed>() &&
+        !from_multi_progress) // Don't std::endl if calling from MultiProgress
+      std::cout << termcolor::reset << std::endl;
+  }
+};
+
+} // namespace indicators