ESP Flasher — GUI Firmware Flashing Tool for ESP32 and ESP8266

ESP Flasher is a free, open-source desktop app for flashing firmware to Espressif ESP32, ESP32-S2/S3/C3/C6/H2, and ESP8266 microcontrollers. It wraps the official esptool in a native JavaFX GUI — no command line needed.

Works on macOS (Apple Silicon + Intel) and Windows. Flash Tasmota, ESPHome, WLED, MicroPython, Arduino, and custom ESP-IDF firmware from a single .bin file. A modern alternative to Tasmotizer and the Espressif Flash Download Tool that runs natively on Mac.

---

Features

• Native .dmg and .msi installers — no Python GUI required to launch
• Popular firmware catalog — one-click flash of Tasmota and Tasmota SML (ottelo9); auto-downloads the correct factory binary for your chip and caches it locally
• Explore Popular Projects view — browse supported firmware with logos and open project repositories directly
• Custom Binary mode for any .bin (ESPHome, WLED, MicroPython, Arduino, ESP-IDF)
• Automatic ESP32/ESP8266 serial port detection (CP210x, CH340, FTDI)
• Selectable chip type, baud rate up to 921600, and custom flash offset
• Live progress bar and real-time esptool log output
• Factory Mode — auto-flashes every ESP board the moment it is plugged in
• Inline Settings view: detected Python/esptool paths, custom path overrides, optional flash-log CSV with MAC-address audit trail
• One-click esptool install via pip if it is missing
• Automatic light / dark theme based on system appearance
• Persistent flash counter for production runs
• 100% open source — MIT license, no telemetry

---

Download

Platform	Installer
macOS (Apple Silicon & Intel)	ESP.Flasher-1.0.4.dmg
Windows	ESP.Flasher-1.0.4.msi

macOS: Drag to Applications. If Gatekeeper blocks it:

xattr -cr "/Applications/ESP Flasher.app"

Windows: Run the .msi. If SmartScreen warns you, choose More info → Run anyway.

Both installers are currently unsigned.

---

Prerequisites

• Python 3 — required by esptool. Install from python.org or Homebrew.
• esptool — the app detects it and offers to install via pip on first launch.
• USB drivers — boards with CP210x or CH340 USB-to-serial chips may need vendor drivers on Windows and older macOS.

---

How to Flash ESP32 or ESP8266 Firmware

Option A — Popular firmware (auto-download)

1. Set Source to a catalogued project (e.g. Tasmota or Tasmota SML (ottelo9)). The latest version is shown next to the dropdown.
2. Pick your Chip — the chip list is filtered to variants the project actually ships.
3. Select the Port and Baud Rate.
4. Click Flash Once. The app downloads the matching factory binary, caches it under ~/.esp-flasher/firmware-cache, and flashes. Switching chips later reuses the cache until a new version is released.

Tip: click Explore Popular Projects → next to the Source dropdown to see all supported firmware with logos and open their GitHub pages.

Option B — Custom binary

1. Set Source to Custom Binary.
2. Click Browse... and pick your firmware .bin file (ESPHome, WLED, MicroPython, Arduino, ESP-IDF, etc.).
3. Select the Chip (or leave on auto to let esptool detect it).
4. Select the Port — click Refresh if your board isn't listed.
5. Choose a Baud Rate — 460800 is a safe default; 921600 is faster if your USB-serial chip supports it.
6. Set the Flash Offset: 0x0 for merged ESP32 binaries and all ESP8266, 0x1000 for ESP32 bootloader-only, 0x10000 for application-only.
7. Click Flash Once.

Factory Mode — Mass Flash ESP Boards

For flashing the same firmware onto many boards in sequence (production runs, classroom kits, repair shops):

1. Select firmware, chip, baud rate, and offset.
2. Click Factory Mode — the app waits for a device.
3. Plug in a board. It flashes automatically.
4. Unplug when done (green bar + chime), plug in the next one.
5. Click Stop Factory when finished. The Flashed: counter tracks your total.

---

Supported Espressif Chips

auto (autodetect), ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6, ESP32-H2, ESP8266.

Works with NodeMCU, Wemos D1 Mini, ESP32 DevKitC, ESP32-S3 DevKitC, ESP32-C3 SuperMini, M5Stack, Seeed XIAO ESP32, LilyGO T-Display, Adafruit Feather ESP32, Sonoff Basic/Mini, and most generic Espressif modules.

---

Building From Source

Requires JDK 17+ and Maven (or the included mvnw wrapper).

# Run from source
./mvnw clean package
java -jar target/espflasher-1.0.4.jar

# Build native installer (DMG on macOS, MSI on Windows)
./mvnw clean package
./mvnw jpackage:jpackage
# Output: target/dist/

---

Troubleshooting

Symptom	Fix
"Python not found"	Install Python 3 from python.org and restart.
"esptool not found"	Click the status label, or run python3 -m pip install esptool.
No ports listed	Install your board's USB-serial driver (CP210x, CH340, FTDI), then click Refresh.
"Timed out connecting to ESP"	Hold BOOT while plugging in. Try a lower baud rate (e.g. 115200).
macOS: "App is damaged and can't be opened"	xattr -cr "/Applications/ESP Flasher.app"
Firmware doesn't run after flash	Check the flash offset — many ESP32 images need 0x1000 or 0x10000.

The full esptool output is visible in the log area — include it when filing an issue.

---

Contributing

Open an issue before starting work. See CONTRIBUTING.md for setup and conventions.

License

MIT — © 2026 Ajinkya Gokhale

Credits

• Espressif Systems — esptool
• Fazecast — jSerialComm
• OpenJFX — JavaFX runtime

---

Keywords: ESP32 flasher, ESP8266 flasher, esptool GUI, flash ESP32 firmware Mac, Tasmotizer alternative macOS, Tasmota flasher, ESPHome flash tool, WLED flasher, ESP32-C3 flasher, ESP32-S3 flasher, factory flash ESP32, mass flashing tool, ESP firmware upload tool.