Open HEX files in your browser
The firmware files of Arduino, STM32, PIC and countless other chips. See what one writes right here, and turn it into a .bin. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your firmware opens as the program it holds, the chip it's for and where it writes in flash.
- The chip it's for • RP2040, RP2350, ESP32, nRF and more
- The program • Its name, version and build date, when it says
- Where it writes • Each region and its size
- Save the flash image as a .bin
About HEX
Intel made the HEX format in the 1970s to send programs to EPROM programmers as plain text, and microcontrollers still use it: the Arduino IDE builds a .hex for each sketch, and STM32CubeIDE, MPLAB, Keil and the micro:bit's editors save them for flashing.
Each line is a record starting with a colon: a length, an address, a type and the bytes as hex digits, then a checksum. Extended records reach past 64 KB, and a last record ends the file.
Filepeek reads every record, checks every checksum and shows each region it writes, its size and the start address, and saves the flash image as a .bin, with gaps filled as erased flash. Text shows the lines as they are.
Intel HEX
.hex • .ihex • .ihx
Format
- MIME type
- text/x-hex
- Made by
- Intel
Inside the file
- Text
- A record a line
- Each line
- Address, bytes and checksum
- Reaches
- 4 GB, with extended records
- Made by
- Compilers and IDEs
Opens in every browser
Browsers show a .hex as text at best. Filepeek reads what it writes in Chrome, Edge, Firefox and Safari.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open HEX
- WindowsSTM32CubeProgrammer and avrdude, free
- Macavrdude, free • STM32CubeProgrammer
- iPhone and iPadNo app opens it
- AndroidNo app opens it
Questions
How do I convert HEX to BIN?
Open it here and save the flash image as a .bin: every byte from the first address on, with gaps filled as erased flash, 0xFF.
What does a checksum error in a .hex mean?
A line was changed or cut short, often by an editor or a bad copy. Filepeek counts the lines whose checksums fail, so you know the file is damaged before you flash it.
How do I flash a .hex file?
With your chip's own tool: avrdude or the Arduino IDE for AVR chips, STM32CubeProgrammer for STM32, MPLAB IPE for PIC, or by copying it to a micro:bit's drive.
Is a .hex file ever a font?
GNU Unifont's .hex files are fonts, and they open in the font viewer. Intel HEX lines start with a colon and open here.