ESP32 log analyzer

Paste the serial output of an ESP32, from the reset on, and get each known line explained: why it reset, what crashed, which error code it printed, why WiFi dropped, and what usually fixes it. Add the ELF and the backtrace is decoded too.

What it recognizes

• Reset reasons from the ROM line, such as rst:0xc (SW_CPU_RESET), rst:0x8 (TG1WDT_SYS_RESET), rst:0x10 (RTCWDT_RTC_RESET) and rst:0xf (BROWNOUT_RST), and the download boot mode.
• Crashes: every Guru Meditation Error reason on Xtensa and RISC-V chips (LoadProhibited, StoreProhibited, InstrFetchProhibited, Load access fault and the rest), NULL pointers from EXCVADDR or MTVAL, stack overflows, abort(), failed asserts and heap corruption.
• Watchdogs: the task watchdog and the interrupt watchdog.
• Power: Brownout detector was triggered.
• Boot problems: invalid header: 0xffffffff, a flash size mismatch, damaged images, a missing app partition.
• Every esp_err_t code of ESP-IDF 5.5, more than 240, by name or number, such as ESP_ERR_NVS_NO_FREE_PAGES or 0x3001, and failed ESP_ERROR_CHECK calls.
• WiFi disconnect reasons, such as 201 NO_AP_FOUND, 15 4WAY_HANDSHAKE_TIMEOUT and 202 AUTH_FAIL.

Nothing is uploaded: the log and the ELF stay in your browser.

For devices that are not on your desk

The log that explains a field failure is printed to a serial port nobody is reading. Pinscope sends the device's ESP_LOG output and crash reports over the internet, keeps the crash across the reboot, and decodes it with your ELF. Remote logging without a cable.

Try it

Three devices are free, and no card is needed. Create an account, or read the five-minute guide first.

More

• Remote access to an ESP32 without TLS: what it measured and what it costs
• Reaching an ESP32 web server from outside its network
• Updating ESP32 firmware over the internet, with rollback
• Guru Meditation Error: decoding the backtrace, and crashes from the field
• Remote logging: ESP_LOG without a serial cable
• Heap and stack monitoring in the field
• An ESP32 behind CGNAT, 4G or Starlink
• TLS memory usage on the ESP32, and how to reduce it
• Sharing an ESP32 sensor page with anyone, without port forwarding
• ArduinoOTA over the internet, with a rollback
• ESP32 remote access compared: port forwarding, ngrok, Cloudflare Tunnel, Tailscale
• esp_http_server slow? The 250 ms delay and the fix
• Before the first ESP32 ships: a field support checklist
• ESP32 exception decoder: a Guru Meditation backtrace to lines, in the browser