![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/10\/ESP32-Credentials-Separate-File.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nThis tutorial was written by one of our readers, Ron Brinkman, and edited by Sara Santos.<\/p>\n\n\n\n
Why Save Your Credentials in a Separate File?<\/h2>\n\n\n\n
Many projects you create require account names, passwords, tokens, or other sensitive information in order for them to work. <\/p>\n\n\n\n
These may be secure if they never leave your desktop, but it can be all too easy to forget and publish or distribute a script file with your personal credentials in it rather than the intended placeholder “REPLACE_WITH_YOUR_PASSWORD”<\/span>. <\/p>\n\n\n\n You can address this by placing your credentials in a separate file in your libraries<\/span> <\/em>folder and including a reference to that file in your sketch initiation. That way, your private credentials will not accidentally escape your desktop and will automatically be included when you compile your sketch.<\/p>\n\n\n\n Additionally, this method removes the need to hardcode credentials or API tokens every time you compile a new sketch that requires them.<\/p>\n\n\n\n You may also like reading: ESP32 Useful Wi-Fi Library Functions (Arduino IDE)<\/a><\/p>\n\n\n\n Here is a quick overview of how our approach works:<\/p>\n\n\n\n We’ll create a library called MyLogin<\/span> that will hold the credentials. You can give it any other name. Follow the next steps to install a skeleton MyLogin<\/em><\/span> file in your library:<\/p>\n\n\n\n 1. Go to the Arduino libraries<\/em> folder. You can find the path for your Arduino libraries<\/em><\/span> folder, by going to File <\/strong>> Preferences<\/strong>. The path in the Sketchbook location<\/em> field is where your libraries<\/em><\/span> folder is located.<\/p>\n\n\n 2. Create a folder named\u00a0MyLogin<\/span>\u00a0<\/em>in your Arduino IDE libraries<\/span>\u00a0<\/em>folder.<\/p>\n\n\n\n 3. Finally, copy the following skeleton code to a file named\u00a0MyLogin.h<\/em><\/span>\u00a0in the MyLogin<\/em><\/span> folder and save it.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Open the skeleton MyLogin.h<\/em><\/span> file in your Arduino IDE installation libraries <\/em>folder. Follow the next steps to isolate personal account, password, and token information in this private file:<\/p>\n\n\n\n 1)<\/strong> Edit the Credentials currently in effect<\/em> section. Write your network credentials in the following definition statements, so that applications can connect to your local network.<\/p>\n\n\n\n 2) <\/strong>Continue editing or adding any other credentials your applications use. This may include SMTP email, SMS messaging, Telegram messaging, WhatsApp instant messaging, Duck DNS, NoIP, DynDNS, or other dynamic DNS support, etc.<\/p>\n\n\n\n For this tutorial, we’ll only be testing the network credentials, but this gives you an idea if you want to add more sensitive information.<\/p>\n\n\n\n 3)<\/strong> Optionally place credentials in the commented-out section of the file so that you don’t need to look them up each time you travel to another location and want to work on your application.<\/p>\n\n\n\n Start with a copy of your home credentials for the case where the Current credentials<\/em> are temporarily overwritten while “on the road”.<\/p>\n\n\n\n 4)<\/strong> Continue customizing with any other family, friend, or business locations’ credentials as needed.<\/p>\n\n\n\n Save the file, now containing your private information. It’s ready to be used by your scripts to keep private information out of the scripts.<\/p>\n\n\n\n Each script file you want to protect from inadvertent disclosure of your credentials will require two simple edits. Follow the next steps:<\/p>\n\n\n\n 1)<\/strong> Place the following statement in your list of #include<\/span> files to include the “library” we created previously:<\/p>\n\n\n\n 2)<\/strong> Find the place in your script file where your account name, password, token, or other credentials would normally be entered. For your WiFi account, it will look something like:<\/p>\n\n\n\n 3) <\/strong>Replace the text with the following:<\/p>\n\n\n\n Don’t fill in your credentials here. They will be incorporated automatically via the MyLogin.h<\/span> file and #include<\/span> statement. This will use the values of the STASSID<\/span> and STAPSK<\/span> variables defined in the MyLogin.h<\/em><\/span> file.<\/p>\n\n\n\n 4) <\/strong>Continue looking for other places in your script where account names, passwords, or tokens are needed for applications such as SMTP email, SMS messaging, Telegram messaging, WhatsApp instant messaging, Duck DNS, NoIP, DynDNS, or other dynamic DNS support, etc.<\/p>\n\n\n\n Update these sections of code, similar to the WiFi credentials, to keep personal information out of the script.<\/p>\n\n\n\n Let’s test what we’ve learned so far with a simple Wi-Fi example.<\/p>\n\n\n\n The following code will connect to your local network and print the RRSI (signal strength) once the connection is established.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n If you’ve successfully created the MyLogin.h<\/em><\/span> file as we explained previously, you don’t need to add any credentials to this code. It will get them through the MyLogin.h<\/em><\/span> file.<\/p>\n\n\n\n The MyLogin.h<\/em><\/span> file, that you have customized per the instructions above, now contains all your personal credentials. It is no longer necessary to enter these credentials anywhere else, because they will be included automatically when the script is compiled.<\/p>\n\n\n\n The MyLogin.h<\/em><\/span> library file is now securely incorporated into your script when it is included at the beginning of your script, and it contains all your personal credentials.<\/p>\n\n\n\n Because your credentials are already incorporated into your script from the included MyLogin.h<\/em><\/span> file, now the credentials are actually incorporated into the script for use in your program.<\/p>\n\n\n\n If other accounts, passwords or tokens are utilized in subsequent sections of your script, they will be securely incorporated as well if you have customized and tailored them as described in the previous sections.<\/p>\n\n\n\n Upload your project to your ESP32 board. It will connect to your local network and print the signal strength.<\/p>\n\n\n As you can see, there’s no need to hardcode your network credentials in the code because they will be included when you include the MyLogin.h<\/em><\/span> file. You can do this with any other code that uses Wi-Fi credentials, or if you need to save other sensitive information like tokens, APIs, passwords, etc.<\/p>\n\n\n\n Your private information will be protected from inadvertent disclosure.<\/p>\n\n\n\n We hope you’ve found this project useful and easy to implement on all of your projects. Enjoy the peace of mind knowing that you can publish or distribute the code for your projects without the fear of “OOPS, I forgot to remove my personal information”. <\/p>\n\n\n\n Additionally, it avoids having to look for the credentials or API keys every time you need them, so you don’t have to hardcode them.<\/p>\n\n\n\n We have other tutorials about Wi-Fi that might be useful:<\/p>\n\n\n\n We hope you\u2019ve found this tutorial useful.<\/p>\n\n\n\n Special thanks to our reader Ron Brinkman<\/strong> who created and wrote the layout for this tutorial.<\/p>\n\n\n\n Ron Brinkman is a retired engineer and project manager who desires to keep current in his career technologies. He has utilized RNT and W3Schools materials to great advantage to give back to others by implementing an animated Christmas display in his front yard, and to advocate for better outcomes in his country.<\/p>\n\n\n\n Learn more about the ESP32 with our resources:<\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" Learn how to securely store Wi-Fi credentials and other sensitive information in a separate file for your ESP32 projects (also works for other Arduino based projects). This approach eliminates the … <\/p>\nProject Overview<\/h2>\n\n\n\n
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Creating\/Installing the MyLogin library<\/h2>\n\n\n\n
![\"Arduino](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/11\/Arduino-IDE-libraries-folder-location.jpg?resize=747%2C487&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n<\/ol>\n\n\n\n
![\"Install](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/11\/Install-MyLogin-File-Arduino-Libraries-Folder.png?resize=639%2C292&quality=100&strip=all&ssl=1\")
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\/*********\n Created by Ron Brinkman\n Complete instructions at https:\/\/RandomNerdTutorials.com\/esp32-save-credentials-separate-file\/\n Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.\n The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.\n*********\/\n\n\/\/ Keep account names, passwords, tokens, etc. current in this file\n\/\/ When visiting another location put their credentials in the "currently in effect" section\n\n\/\/ Credentials currently in effect\n#define STASSID "REPLACE_WITH_YOUR_SSID" \/\/ WiFi\n#define STAPSK "REPLACE_WITH_YOUR_PASSWORD"\n\n#define emailSenderAccount "YOUR_SENDER_EMAIL@gmail.com" \/\/ Email\n#define emailSenderPassword "YOUR_EMAIL_APP_PASSWORD"\n#define emailRecipient "YOUR_EMAIL_RECIPIENT@example.com"\n\n#define DuckDNStoken "YOUR_DUCKDNS_TOKEN" \/\/ DuckDNS\n\n\/*********Saved credentials for substitution above when "on the road"\n\/\/Credentials used at home\n#define STASSID "my_wifi_ssid"\n#define STAPSK "my_wifi_password"\n#define emailSenderAccount "my_sender_email@gmail.com"\n#define emailSenderPassword "my_email_app_password"\n#define emailRecipient "my_email_recipient@example.com"\n#define DuckDNStoken "my_duckdns_token"\n\n\/\/ Credentials used at Mom and Dad's house\n#define STASSID "parents_wifi_ssid"\n#define STAPSK "parents_wifi_password"\n\n\/\/ Credentials used at wife's Mom and Dad's house\n#define STASSID "wifes_parents_wifi_ssid"\n#define STAPSK "wifes_parents_wifi_password"\n\n\/\/ Credentials used at our daughter's house\n#define STASSID "daughter_wifi_ssid"\n#define STAPSK "daughter_wifi_password"\n\n\/\/ Credentials used at our son's house\n#define STASSID "son_wifi_ssid"\n#define STAPSK "son_wifi_password"\n\n\/\/ Credentials used at our friends Joe and Sally's house\n#define STASSID "friend_wifi_ssid"\n#define STAPSK "friend_wifi_password"\n*********\/\n<\/code><\/pre>\n\tCustomize the MyLogin.h<\/em> file with your credentials<\/h3>\n\n\n\n
\/\/ Credentials currently in effect\n#define STASSID \"REPLACE_WITH_YOUR_SSID\" \/\/ WiFi\n#define STAPSK \"REPLACE_WITH_YOUR_PASSWORD\"<\/code><\/pre>\n\n\n\n#define emailSenderAccount \"YOUR_SENDER_EMAIL@gmail.com\" \/\/ Email\n#define emailSenderPassword \"YOUR_EMAIL_APP_PASSWORD\"\n#define emailRecipient \"YOUR_EMAIL_RECIPIENT@example.com\"\n\n#define DuckDNStoken \"YOUR_DUCKDNS_TOKEN\" \/\/ DuckDNS<\/code><\/pre>\n\n\n\n\/\/ Saved credentials for substitution above when \"on the road\"\n\/\/ Credentials used at home\n#define STASSID \"my_wifi_ssid\"\n#define STAPSK \"my_wifi_password\"\n#define emailSenderAccount \"my_sender_email@gmail.com\"\n#define emailSenderPassword \"my_email_app_password\"\n#define emailRecipient \"my_email_recipient@example.com\"\n#define DuckDNStoken \"my_duckdns_token<\/code><\/pre>\n\n\n\n\/\/ Credentials used at Mom and Dad's house\n#define STASSID \"wifes_parents_wifi_ssid\"\n#define STAPSK \"wifes_parents_wifi_password\"\n .\n .\n .<\/code><\/pre>\n\n\n\nTailoring Your Script Files<\/h2>\n\n\n\n
#include <MyLogin.h><\/code><\/pre>\n\n\n\n\/\/ Replace with your network credentials\nconst char* ssid = \"REPLACE_WITH_YOUR_SSID\";\nconst char* password = \"REPLACE_WITH_YOUR_PASSWORD\";<\/code><\/pre>\n\n\n\nconst char* ssid = STASSID;\nconst char* password = STAPSK;<\/code><\/pre>\n\n\n\nTesting with a Wi-Fi Connection Code<\/h2>\n\n\n\n
\/*********\n Created by Ron Brinkman\n Complete instructions at https:\/\/RandomNerdTutorials.com\/esp32-save-credentials-separate-file\/\n*********\/\n\n#include <WiFi.h>\n#include <MyLogin.h>\n\n\/\/ Replace with your network credentials (STATION)\nconst char* ssid = STASSID;\nconst char* password = STAPSK;\n\nvoid initWiFi() {\n WiFi.mode(WIFI_STA);\n WiFi.begin(ssid, password);\n Serial.print("Connecting to WiFi ..");\n while (WiFi.status() != WL_CONNECTED) {\n Serial.print('.');\n delay(1000);\n }\n Serial.println(WiFi.localIP());\n}\n\nvoid setup() {\n Serial.begin(115200);\n initWiFi();\n Serial.print("RSSI: ");\n Serial.println(WiFi.RSSI());\n}\n\nvoid loop() {\n \/\/ put your main code here, to run repeatedly:\n}\n<\/code><\/pre>\n\tHow Does the Code Work?<\/h3>\n\n\n\n
#include <MyLogin.h><\/code><\/pre>\n\n\n\nconst char* ssid = STASSID;\nconst char* password = STAPSK;<\/code><\/pre>\n\n\n\nDemonstration<\/h3>\n\n\n\n
![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/10\/ESP32-connects-to-Wi-Fi-RSSI-Serial-Monitor.png?resize=666%2C674&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nWrapping Up<\/h2>\n\n\n\n
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