Hey Jordan, this is a solid security question—exposing plaintext passwords in the DOM (even just in dev tools) is a risk we definitely want to avoid. Let's walk through how to fix this properly.

The Root Problem #

When you set the value attribute directly in your HTML <input> tag, that plaintext gets baked into the DOM. Browsers will show this value in the Inspect Element panel, no matter that the input is type="password". That's why your example with value="ciao" is visible to anyone who opens dev tools.

Step 1: Remove the Value Attribute from HTML #

First, strip out the value attribute entirely from your input tag. This ensures the plaintext never makes it into the initial DOM markup. Your cleaned-up input should look like this:

<input class="form-control valid form-control-sm " placeholder="password" id="PASS" name="PASS" maxlength="200" type="password" >

Step 2: Handle Pre-Filling Safely (If Needed) #

If you absolutely need to pre-fill the password (e.g., for a remembered user session), don't hardcode it in HTML. Instead, use JavaScript to set the input's value dynamically after the page loads. Even though the value will still show up in dev tools once set, this prevents it from being visible in the raw page source:

// Run this after the DOM is fully loaded
document.addEventListener('DOMContentLoaded', function() {
  // Only do this if you're retrieving the password securely (e.g., from an encrypted session)
  document.getElementById('PASS').value = 'your-securely-retrieved-password';
});

⚠️ Important: Never pass plaintext passwords from your backend to the frontend unless absolutely necessary. Use secure session tokens instead, and let browsers handle password auto-filling (they use encrypted storage which is far more secure than custom implementations).

Extra Security Best Practices #

• Let Browsers Handle Auto-Fill: Avoid setting autocomplete="off" unless you have a specific reason—browsers' built-in password managers are safer than rolling your own.
• Use HTTPS: Always transmit passwords over HTTPS to prevent interception during submission.
• Never Store Plaintext: Even on the frontend, avoid storing plaintext passwords in variables or local storage for longer than necessary.

内容的提问来源于stack exchange，提问作者Jordan.M