ESP32 Web Flasher

Flash ESP32 firmware directly from your browser using Web Serial API. No drivers or desktop tools needed.

How to flash multiple .bin files (bootloader + partition + firmware)

ESP32 firmware can be flashed in two ways: as separate files or as a single merged file.

Option 1: Merged Firmware (Recommended)

  • • Use our Firmware Merger tool first
  • • Upload the single merged .bin file
  • • Set offset to 0x0
  • • Flash - all components are written to correct positions

Option 2: Separate Files (Traditional)

ESP32 firmware typically consists of three separate files:

OffsetFileDescription
0x0bootloader.binFirst-stage bootloader
0x8000partitions.binPartition table layout
0x10000firmware.binApplication firmware

For Merged Firmware:

  1. Click Connect Device and select your ESP32
  2. Upload your merged .bin file at offset 0x0
  3. Click Flash Firmware

For Separate Files:

  1. Click Connect Device and select your ESP32
  2. Click + Add file to create rows for each .bin file (3 total)
  3. Set the offset and select the matching .bin for each row
  4. Click Flash Firmware

These are the default offsets for ESP-IDF and Arduino. If your project uses a custom partition table, check your build output or partitions.csv for the correct addresses.

PRO

Batch Flashing

Flash multiple ESP32 devices with guided workflows, progress tracking, and quality assurance reporting.

Manual Mode:

• Guided device swapping

• Quality control checkpoints

• Batch progress tracking

Auto Mode:

• Automatic device detection

• Serial number injection

• Production reporting

Web Serial API not supported

Use Chrome, Edge, or Opera on desktop to access Web Serial.

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