Toolsο
idf.py flash default behavior (fast reflash)ο
The default behavior of idf.py flash has changed. When *_flashed.bin files exist in the build directory (e.g. from a previous successful flash), idf.py flash now performs fast reflashing: it only writes the flash regions that changed, which speeds up repeated flashing during development. After flashing, it verifies that the device flash content matches the expected binaries; if verification fails, a full flash is performed.
If you prefer the previous behavior where all binaries are always written in full (regardless of existing *_flashed.bin files), you can force a complete flash by using the full flash mode: run idf.py flash -a or idf.py flash --all. This ensures that every binary is re-written to the device, which is recommended when working with brand-new, empty, or erased chips, or whenever you want to disable fast reflash and incremental flashing.
For more details, see Flash the Project: flash in the IDF Python Tools guide.