A lightweight Arduino/embedded library to expose a device filesystem over FTP, allowing uploads, downloads and remote file management from standard FTP clients (FileZilla, WinSCP, Explorer, etc.). This version supports a single FTP session.

Author: Renzo Mischianti Website: www.mischianti.org GitHub: xreef/SimpleFTPServer

Complete tutorials and platform-specific guides by the author are available on mischianti.org.

• 🌐 Simple FTP Server Library Home - Main library page with articles and examples
• 📖 FTP server on ESP8266 and ESP32 - Getting started guide
• 📖 Simple FTP server library now with support for Wio Terminal and SD

• Features
• Supported Platforms
• Supported Network Interfaces
• Supported Storage Systems
• Installation
• Basic Usage
• Configuration
• Included Examples
• Changelog
• License
• Contributing
• Support & Contact

• Expose device filesystem via a single FTP session (upload, download, delete, rename, list)
• Resume support (REST) and RFC-like commands (ALLO, STAT, SYST, HELP)
• UTF-8 filename support (configurable)
• Configurable buffers and timeouts via FtpServerKey.h
• Works with internal flash filesystems (SPIFFS, LittleFS, FFAT) and external SD (SD, SdFat)
• Small footprint and simple API: begin() and handleFTP()

⚠️ Note: Some older AVR boards (Uno/Mega) have limited RAM and may not support large transfers.

• WiFi (ESP32, ESP8266, RP2040-W, WiFiNINA)
• Ethernet (W5x00, W5500, ENC28J60, ESP32-ETH)
• Seeed RTL8720DN

• SPIFFS (ESP8266/ESP32)
• LittleFS (ESP8266/ESP32/RP2040)
• FFAT (ESP32)

• SD (Arduino SD library)
• SdFat / SdFat2 (recommended)
• SD_MMC (ESP32)
• Adafruit_SPIFlash

1. Open Arduino IDE
2. Sketch > Include Library > Manage Libraries
3. Search for "SimpleFTPServer" and install

1. Copy the repository folder into your Arduino libraries/ folder
2. Restart Arduino IDE

Add to platformio.ini:

lib_deps = xreef/SimpleFTPServer

#include <WiFi.h>
#include "SPIFFS.h"
#include <SimpleFTPServer.h>

const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASS";

FtpServer ftpSrv;

void setup(){
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Connected. IP: ");
  Serial.println(WiFi.localIP());

  // Mount filesystem before starting FTP
  if (SPIFFS.begin(true)) {
      Serial.println("SPIFFS opened!");
      // username, password for ftp.
      ftpSrv.begin("esp32","esp32");
  }
}

void loop(){
  ftpSrv.handleFTP();
}

See FtpServerKey.h for config defines and defaults. Key settings:

• FTP_BUF_SIZE — transfer buffer size
• FTP_TIME_OUT — inactivity timeout (seconds)
• FTP_AUTH_TIME_OUT — authentication timeout (seconds)
• DEBUG_PRINTER — debug output stream (defaults to Serial)
• UTF8_SUPPORT — enable/disable UTF-8 support

See the examples/ folder for ready-to-use sketches for many platforms (ESP32, ESP8266, RP2040, STM32, Wio Terminal, Arduino). Adapt SSID, credentials and SD pins as needed.

• 2025-10-13 3.0.0 Fix:
  • updated SdFat2 initialization for Arduino Mega; integrated W5500 initialization (example Arduino_Mega_W5500_SdFat2)
  • Fix READ WRITE APPEND problem
  • Fix ram usage
  • Set correct buffer size (Dynamic and Static)
  • Add FTP callbacks for connection events and file transfers; update data types for free space and transferred size
  • Improve file-open handling (ensure reads start at file beginning), increase passive data connection wait time, add robust FFat dir create/remove (fallback to /ffat and POSIX), add configurable minimum free-space check before uploads
  • Refactor FTP callback functions to use uint32_t for space parameters, improve serial output, and register callbacks for FTP events
• 2025-02-11 2.1.11 Management of relative and absolute path in command prompt (./ ../ /)
• 2025-01-28 2.1.11 Fix REST and add ALLO, and STAT commands
• 2025-01-13 2.1.11 Add addictional LOG to prevent multiple user issues
• 2025-01-12 2.1.11 Add REST (resume) command
• 2025-01-11 2.1.10 Multiple minor fix and optimization
• 2024-09-16 2.1.9 Fix LittleFS filename size.
• 2024-07-16 2.1.8 Add SYST command.
• 2023-10-07 2.1.7 Fix ESP32 rename on SD (thanks @scuba-hacker) #44
• 2023-02-02 2.1.6 Fix esp8266 Ethernet (w5x00) issue and explain solution for ESP32 Ethernet (w5x00), add new Networks management
• 2023-01-13 2.1.5 Fix SPIFM external SPI Flash date management (add SPIFM esp32 example)
• 2022-09-21 2.1.4 Add support for Raspberry Pi Pico W and rp2040 boards, Fix SD card config
• 2022-09-20 2.1.3 Soft AP IP management, more disconnect event and SD_MCC
• 2022-05-21 2.1.2 Fix SD path (#19)
• 2022-05-21 2.1.1 Minor fix
• 2022-03-30 2.1.0 Add UTF8 support and enabled It by default (Thanks to @plaber)
• 2022-03-30 2.0.0 Complete support for STM32 with SD and SPI Flash minor bux fix and HELP command support
• 2022-03-17 1.3.0 Fix enc28j60 and w5500 support and restructuring for local settings
• 2022-02-25 1.2.1 Fix anonymous user begin and fix SPIFFS wrong display
• 2022-02-22 1.2.0 Add anonymous user and implement correct RFC (#9 now work correctly with File Explorer)
• 2022-02-01 1.1.1 Add workaround to start FTP server before connection, add end and setLocalIP method.

MIT License — see LICENSE.md for details.

Copyright (c) 2017-2025 Renzo Mischianti

Contributions are welcome! Fork the repo, create a feature branch, commit and submit a Pull Request. Please ensure examples build on target platforms before opening a PR.

• Website: https://www.mischianti.org/category/my-libraries/simple-ftp-server/
• GitHub Issues: https://github.com/xreef/SimpleFTPServer/issues
• Forum / Articles: https://www.mischianti.org/

Renzo Mischianti Website: https://www.mischianti.org Email: [email protected] GitHub: @xreef

⭐ If this library helped your project, please star the repository on GitHub!