AT Command Set


Here is a list of AT commands. Some of them can only work on the ESP32 series, so they are marked as [ESP32 Only] at the beginning; those without any mark can work on all ESP series, including ESP32, ESP8266, ESP32-S2, and ESP32-C3.

It is strongly recommended to read the following sections for some common information on AT commands before you dive into the details of each command.

AT Command Types

Generic AT command has four types:


Command Format


Test Command


Query the Set Commands’ internal parameters and their range of values.

Query Command


Return the current value of parameters.

Set Command


Set the value of user-defined parameters in commands, and run these commands.

Execute Command


Run commands with no user-defined parameters.

  • Not all AT commands support all of the four types mentioned above.

  • Currently, only strings and integer numbers are supported as input parameters in AT commands.

  • Angle brackets < > designate parameters that can not be omitted.

  • Square brackets [ ] designate optional parameters that can be omitted. The default value of the parameter will be used instead when you omit it. Below are examples of entering the command AT+CWJAP with some parameters omitted.

  • If the parameter you want to omit is followed by a parameter(s), you must give a , to indicate it.

  • String values need to be included in double quotation marks.

  • Escape character syntax is needed if a string contains special characters, such as ,, ", or \:

    • \\: escape the backslash itself

    • \,: escape comma which is not used to separate each parameter

    • \": escape double quotation mark which is not used to mark string input

    • \<any>: escape <any> character means that drop backslash symbol and only use <any> character

  • Escape is needed in AT commands only, not elsewhere. For example, when AT command port prints > and wait for your input, the input does not need to be escaped.

  • The default baud rate of AT command is 115200.

  • The length of each AT command should be no more than 256 bytes.

  • AT commands end with a new-line (CR-LF), so the serial tool should be set to “New Line Mode”.

  • Definitions of AT command error codes are provided in AT API Reference:

AT Commands with Configuration Saved in the Flash

Configuration settings entered by the following AT Commands will always be saved in the flash NVS Area, so they can be automatically restored on reset:

Saving of configuration settings by several other commands can be switched on or off with AT+SYSSTORE command, which is mentioned in the Note section of these commands.

AT Messages

There are two types of ESP-AT messages returned from the ESP-AT command port:

  • ESP-AT Response Messages (passive)

    Each ESP-AT command input returns response messages to tell the sender the result of the ESP-AT command.

    ESP-AT Response Messages

    AT Response Messages



    AT command process done and return OK


    AT command error or error occurred during the execution


    Data has been sent to the protocol stack (specific to AT+CIPSEND and AT+CIPSENDEX command). It doesn’t mean that the data has been sent to the opposite end


    Error occurred during sending the data to the protocol stack (specific to AT+CIPSEND and AT+CIPSENDEX command

    +<Command Name>:...

    Response to the sender that describes AT command process results in details

  • ESP-AT Message Reports (active)

    ESP-AT will report important state changes or messages in the system.

    ESP-AT Message Reports

    ESP-AT Message Report



    The ESP-AT firmware is ready

    busy p…

    Busy processing. The system is in process of handling the previous command, thus CANNOT accept the new input

    ERR CODE:<0x%08x>

    Error code for different commands

    Will force to restart!!!

    Module restart right now

    smartconfig type:<xxx>

    Smartconfig type

    Smart get wifi info

    Smartconfig has got the SSID and PASSWORD information

    smartconfig connected wifi

    Smartconfig done. ESP-AT has connected to the Wi-Fi


    Wi-Fi station interface has connected to an AP


    Wi-Fi station interface has got the IPv4 address


    Wi-Fi station interface has got the IPv6 LinkLocal address


    Wi-Fi station interface has got the IPv6 Global address


    Wi-Fi station interface has disconnected from an AP


    Ethernet interface has connected


    Ethernet interface has got the IPv4 address


    Ethernet interface has disconnected


    A network connection of which ID is <conn_id> is established (ID=0 by default)


    A network connection of which ID is <conn_id> ends (ID=0 by default)


    Detailed connection information of TCP/UDP/SSL

    +STA_CONNECTED: <sta_mac>

    A station has connected to the Wi-Fi softAP interface of ESP-AT

    +DIST_STA_IP: <sta_mac>,<sta_ip>

    The Wi-Fi softAP interface of ESP-AT distributes an IP address to the station

    +STA_DISCONNECTED: <sta_mac>

    A station disconnected from the Wi-Fi softAP interface of ESP-AT


    ESP-AT is waiting for more data to be received

    Recv <xxx> bytes

    ESP-AT has already received <xxx> bytes from the ESP-AT command port


    ESP-AT received the data from the network

    SEND Canceled

    Cancel to send in Wi-Fi normal sending mode

    Have <xxx> Connections

    Has reached the maximum connection counts for server


    ESP-AT quits from the Wi-Fi Passthrough Mode


    No valid device certificate found in custom partition


    No valid private key found in custom partition


    No valid CA certificate found in custom partition


    MQTT connected to the broker


    MQTT disconnected from the broker


    MQTT received the data from the broker


    MQTT failed to publish data


    MQTT publish data done


    A Bluetooth LE connection established


    A Bluetooth LE connection ends


    A read operation from Bluetooth LE connection


    A write operation from Bluetooth LE connection


    A notification from Bluetooth LE connection


    An indication from Bluetooth LE connection


    Bluetooth LE SMP key


    Received encryption request which index is <conn_index>


    Bluetooth LE SMP pairing completed