diff --git a/firmware/keira/platformio.ini b/firmware/keira/platformio.ini
index 411d95c1..2d427d4c 100644
--- a/firmware/keira/platformio.ini
+++ b/firmware/keira/platformio.ini
@@ -28,6 +28,7 @@ lib_deps =
 	https://github.com/moononournation/arduino-nofrendo.git
 	bitbank2/PNGenc @ ^1.1.1
 	bblanchon/ArduinoJson @ ^7.0.4
+	lennarthennigs/ESP Telnet @ ^2.2.1
 	https://github.com/earlephilhower/ESP8266Audio.git
 lib_extra_dirs = ./lib
 extra_scripts = targets.py
diff --git a/firmware/keira/src/apps/launcher.cpp b/firmware/keira/src/apps/launcher.cpp
index 60f1a740..c670f491 100644
--- a/firmware/keira/src/apps/launcher.cpp
+++ b/firmware/keira/src/apps/launcher.cpp
@@ -203,7 +203,7 @@ void LauncherApp::sdBrowserMenu(FS* fSysDriver, const String& path) {
         uint16_t color = entries[i].type == lilka::EntryType::ENT_DIRECTORY ? lilka::colors::Arylide_yellow
                                                                             : get_file_color(filename);
         if (entries[i].type != lilka::EntryType::ENT_DIRECTORY)
-            menu.addItem(filename, icon, color, lilka::fileutils.getHumanFriendlySize(entries[i].size));
+            menu.addItem(filename, icon, color, lilka::fileutils.getHumanFriendlySize(entries[i].size, true));
         else menu.addItem(filename, icon, color);
     }
     menu.addItem("<< Назад", 0, 0);
diff --git a/firmware/keira/src/main.cpp b/firmware/keira/src/main.cpp
index f973c911..cff13ee7 100644
--- a/firmware/keira/src/main.cpp
+++ b/firmware/keira/src/main.cpp
@@ -8,6 +8,7 @@
 #include "services/clock.h"
 #include "services/network.h"
 #include "services/screenshot.h"
+#include "services/telnet.h"
 #include "apps/statusbar.h"
 #include "apps/launcher.h"
 
@@ -20,6 +21,7 @@ void setup() {
     serviceManager->addService(new NetworkService());
     serviceManager->addService(new ClockService());
     serviceManager->addService(new ScreenshotService());
+    serviceManager->addService(new TelnetService());
     appManager->setPanel(new StatusBarApp());
     appManager->runApp(new LauncherApp());
 }
diff --git a/firmware/keira/src/service.cpp b/firmware/keira/src/service.cpp
index bb6e4344..5ef0d752 100644
--- a/firmware/keira/src/service.cpp
+++ b/firmware/keira/src/service.cpp
@@ -7,14 +7,14 @@ Service::~Service() {
 }
 
 void Service::start() {
-    Serial.println("Starting service " + String(name));
+    lilka::serial_log("Starting service %s", name);
     xTaskCreate(_run, name, stackSize, this, 1, &taskHandle);
 }
 
 void Service::_run(void* arg) {
     Service* service = static_cast<Service*>(arg);
     service->run();
-    Serial.println("Service " + String(service->name) + " died");
+    lilka::serial_err("Service %s died", service->name);
 }
 
 void Service::setStackSize(uint32_t stackSize) {
diff --git a/firmware/keira/src/services/network.cpp b/firmware/keira/src/services/network.cpp
index 1bdc09ed..c6910c7c 100644
--- a/firmware/keira/src/services/network.cpp
+++ b/firmware/keira/src/services/network.cpp
@@ -6,6 +6,11 @@
 
 #include "network.h"
 
+// Macro magic used to convert decimal constant to char[] constant
+#define STRX(x)               #x
+#define STR(x)                STRX(x)
+#define LILKA_HOSTNAME_PREFIX "LilkaV"
+
 // EEPROM preferences used:
 // - network.last_ssid - last connected SSID
 // - network.[SSID_hash]_pw - password of known network with a given SSID
diff --git a/firmware/keira/src/services/network.h b/firmware/keira/src/services/network.h
index 9af20ae5..38616593 100644
--- a/firmware/keira/src/services/network.h
+++ b/firmware/keira/src/services/network.h
@@ -2,10 +2,7 @@
 
 #include <WiFi.h>
 #include "service.h"
-// Macro magic used to convert decimal constant to char[] constant
-#define STRX(x)               #x
-#define STR(x)                STRX(x)
-#define LILKA_HOSTNAME_PREFIX "LilkaV"
+
 enum NetworkState {
     NETWORK_STATE_OFFLINE,
     NETWORK_STATE_CONNECTING,
diff --git a/firmware/keira/src/services/telnet.cpp b/firmware/keira/src/services/telnet.cpp
new file mode 100644
index 00000000..9a68bc78
--- /dev/null
+++ b/firmware/keira/src/services/telnet.cpp
@@ -0,0 +1,181 @@
+#include <EscapeCodes.h>
+
+#include "telnet.h"
+#include "servicemanager.h"
+#include "network.h"
+
+#define STR_HELPER(x) #x
+#define STR(x)        STR_HELPER(x)
+
+ESPTelnet telnet;
+EscapeCodes ansi;
+
+TelnetService::TelnetService() : Service("telnet") {
+}
+
+TelnetService::~TelnetService() {
+}
+
+typedef struct {
+    const char* command;
+    void (*function)(String);
+} Command;
+
+Command commands[] = {
+    {
+        "help",
+        [](String args) {
+            telnet.println("Доступні команди:");
+            telnet.println("  help          - показати цей список команд");
+            telnet.println("  reboot        - перезавантажити пристрій");
+            telnet.println("  uptime        - показати час роботи пристрою");
+            telnet.println("  free          - показати стан пам'яті");
+            telnet.println("  ls [DIR]      - показати список файлів на SD-картці");
+            telnet.println("  find [TEXT]   - знайти файли на SD-картці, які містять TEXT в назві");
+            telnet.println("  exit          - розірвати з'єднання");
+        },
+    },
+    {
+        "reboot",
+        [](String args) {
+            telnet.println("Система перезавантажується...");
+            telnet.disconnectClient();
+            esp_restart();
+        },
+    },
+    {
+        "uptime",
+        [](String args) { telnet.println("Uptime: " + String(millis() / 1000) + " seconds"); },
+    },
+    {
+        "free",
+        [](String args) {
+            telnet.println("Heap: " + String(ESP.getFreeHeap()) + " / " + String(ESP.getHeapSize()) + " bytes free");
+            telnet.println("PSRAM: " + String(ESP.getFreePsram()) + " / " + String(ESP.getPsramSize()) + " bytes free");
+        },
+    },
+    {
+        "ls",
+        [](String args) {
+            File dir = SD.open(args.isEmpty() ? "/" : ("/" + args));
+            int count = 0;
+            if (!dir) {
+                telnet.println("Не вдалося відкрити директорію: " + args);
+                return;
+            }
+            while (File file = dir.openNextFile()) {
+                count++;
+                file.isDirectory() ? telnet.print("DIR ") : telnet.print("FILE");
+                telnet.print("  ");
+                telnet.printf(
+                    "%8s  ", !file.isDirectory() ? lilka::fileutils.getHumanFriendlySize(file.size()).c_str() : "-"
+                );
+                telnet.println(file.name());
+                file.close();
+            }
+            dir.close();
+            telnet.println("Знайдено " + String(count) + " файлів");
+        },
+    },
+    {
+        "find",
+        [](String args) {
+            std::vector<String> dirs;
+            dirs.push_back("/");
+            int count = 0;
+            while (!dirs.empty()) {
+                String dir = dirs.back();
+                dirs.pop_back();
+                File d = SD.open(dir);
+                if (!d) {
+                    telnet.println("Не вдалося відкрити директорію: " + dir);
+                    continue;
+                }
+                while (File file = d.openNextFile()) {
+                    String fullPath = (!dir.equals("/") ? dir : "") + "/" + file.name();
+                    if (file.isDirectory()) {
+                        dirs.push_back(fullPath);
+                    } else if (args.isEmpty() || String(file.name()).indexOf(args) != -1) {
+                        count++;
+                        telnet.print("FILE  ");
+                        telnet.printf("%8s  ", lilka::fileutils.getHumanFriendlySize(file.size()).c_str());
+                        telnet.println(fullPath);
+                    }
+                    file.close();
+                }
+                d.close();
+            }
+            telnet.println("Знайдено " + String(count) + " файлів");
+        },
+    },
+    {
+        "exit",
+        [](String args) { telnet.disconnectClient(); },
+    },
+};
+
+void TelnetService::run() {
+    NetworkService* network = ServiceManager::getInstance()->getService<NetworkService>("network");
+
+    telnet.onConnectionAttempt([](String ip) {
+        lilka::serial_log("TelnetService: %s attempting to connect", ip.c_str());
+    });
+    telnet.onConnect([](String ip) {
+        lilka::serial_log("TelnetService: %s connected", ip.c_str());
+        telnet.print(ansi.cls());
+        telnet.print(ansi.home());
+        telnet.println(ansi.setBG(ANSI_BLUE) + "      " + ansi.reset() + " Keira OS @ Lilka v" STR(LILKA_VERSION));
+        telnet.println(ansi.setBG(ANSI_YELLOW) + "      " + ansi.reset() + " Слава Україні! ");
+        telnet.println();
+        telnet.print("> ");
+    });
+    telnet.onReconnect([](String ip) { lilka::serial_log("TelnetService: %s reconnected", ip.c_str()); });
+    telnet.onDisconnect([](String ip) { lilka::serial_log("TelnetService: %s disconnected", ip.c_str()); });
+    telnet.onInputReceived([](String input) {
+        lilka::serial_log("TelnetService: received text: %s", input.c_str());
+        input.trim();
+        if (!input.isEmpty()) {
+            int spaceIndex = input.indexOf(' ');
+            if (spaceIndex == -1) {
+                spaceIndex = input.length();
+            }
+            String command = input.substring(0, spaceIndex);
+            command.toLowerCase();
+            command.trim();
+            String args = input.substring(spaceIndex + 1);
+            args.trim();
+            Command* cmd = &commands[0];
+            for (int i = 0; i < sizeof(commands) / sizeof(Command); i++) {
+                if (command.equals(commands[i].command)) {
+                    cmd = &commands[i];
+                    break;
+                }
+            }
+            cmd->function(args);
+        }
+        telnet.print("> ");
+    });
+
+    bool wasOnline = false;
+    while (1) {
+        if (!network) {
+            vTaskDelay(1000 / portTICK_PERIOD_MS);
+            continue;
+        }
+        bool isOnline = network->getNetworkState() == NetworkState::NETWORK_STATE_ONLINE;
+        if (!wasOnline && isOnline) {
+            wasOnline = true;
+            // Start telnet server
+            telnet.begin(23);
+        } else if (wasOnline && !isOnline) {
+            wasOnline = false;
+            // Stop telnet server
+            telnet.stop();
+        }
+        if (isOnline) {
+            telnet.loop();
+        } else {
+            vTaskDelay(500 / portTICK_PERIOD_MS);
+        }
+    }
+}
diff --git a/firmware/keira/src/services/telnet.h b/firmware/keira/src/services/telnet.h
new file mode 100644
index 00000000..5039f689
--- /dev/null
+++ b/firmware/keira/src/services/telnet.h
@@ -0,0 +1,12 @@
+#include <ESPTelnet.h>
+
+#include "service.h"
+
+class TelnetService : public Service {
+public:
+    TelnetService();
+    ~TelnetService();
+
+private:
+    void run() override;
+};
diff --git a/sdk/lib/lilka/src/lilka/fileutils.cpp b/sdk/lib/lilka/src/lilka/fileutils.cpp
index 06124d19..afcbb3f5 100644
--- a/sdk/lib/lilka/src/lilka/fileutils.cpp
+++ b/sdk/lib/lilka/src/lilka/fileutils.cpp
@@ -1,6 +1,8 @@
 #include "fileutils.h"
 #include "serial.h"
 #include "spi.h"
+#include "config.h"
+
 namespace lilka {
 FileUtils::FileUtils() : sdMutex(xSemaphoreCreateMutex()) {
     sdfs = &SD;
@@ -205,12 +207,12 @@ const String FileUtils::getSDRoot() {
 const String FileUtils::getSPIFFSRoot() {
     return LILKA_SPIFFS_ROOT;
 }
-const String FileUtils::getHumanFriendlySize(const size_t size) {
+const String FileUtils::getHumanFriendlySize(const size_t size, bool compact) {
     // Max length of file size
 
     const char* suffixes[] = {"B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"};
     const int numSuffixes = sizeof(suffixes) / sizeof(suffixes[0]);
-    if (size == 0) return "0B";
+    if (size == 0) return String("0") + (compact ? "" : "  ") + suffixes[0];
 
     int exp = 0;
     double dsize = (double)(size);
@@ -221,13 +223,13 @@ const String FileUtils::getHumanFriendlySize(const size_t size) {
     }
 
     char buffer[50];
-    snprintf(buffer, sizeof(buffer), "%.0f%s", dsize, suffixes[exp]);
-    String hFileSize(buffer);
-    while (hFileSize.length() != H_FILE_SIZE) {
-        hFileSize = hFileSize + " ";
+    if (compact) {
+        snprintf(buffer, sizeof(buffer), "%.0f%s", dsize, suffixes[exp]);
+    } else {
+        snprintf(buffer, sizeof(buffer), "%.0f %2s", dsize, suffixes[exp]);
     }
 
-    return hFileSize;
+    return String(buffer);
 }
 
 bool FileUtils::createSDPartTable() {
diff --git a/sdk/lib/lilka/src/lilka/fileutils.h b/sdk/lib/lilka/src/lilka/fileutils.h
index 67ca148a..2bf91e39 100644
--- a/sdk/lib/lilka/src/lilka/fileutils.h
+++ b/sdk/lib/lilka/src/lilka/fileutils.h
@@ -1,16 +1,13 @@
 #pragma once
 #include <ff.h>
-#include "config.h"
 #include <SPIFFS.h>
 #include <SD.h>
-#include "config.h"
 #include <dirent.h>
 #include <sd_diskio.h>
 
 #define LILKA_SD_ROOT      "/sd"
 #define LILKA_SPIFFS_ROOT  "/spiffs"
 #define LILKA_SLASH        "/"
-#define H_FILE_SIZE        6
 #define LILKA_SD_FREQUENCY 20000000
 
 namespace lilka {
@@ -137,12 +134,13 @@ class FileUtils {
     /// Повернути розмір в читабельному форматі (наприклад, 101 MB).
     ///
     /// @param size Розмір (в байтах)
+    /// @param compact Чи виводити розмір компактно (наприклад, 1.23MB замість 1.23 MB)
     /// @return Рядок, що містить читабельний розмір з суфіксами одиниць виміру
     ///
     /// @code
     /// fileutils.getHumanFriendlySize(1234567); // Поверне "1.23 MB"
     /// @endcode
-    const String getHumanFriendlySize(const size_t size);
+    const String getHumanFriendlySize(const size_t size, bool compact = false);
 
 private:
     SemaphoreHandle_t sdMutex = NULL;