Password Strength Indicator using REGEX

In the digital age, where personal and sensitive information is constantly being shared online, ensuring the security of user accounts has become paramount. Hackers have devised numerous tactics, such as brute force attacks, dictionary attacks, and social engineering, to gain unauthorized access to accounts. As a result, online security has never been more critical. While there are several strategies to fortify your defenses, one of the most effective measures is the use of complex passwords. In this article, we'll delve into the significance of using complex passwords and how they serve as a robust shield against potential cyber threats.

What is a strong Password?

Defining a strong or complex password might vary depending on individual opinions, but there are some essential criteria that universally determine password strength. When evaluating what constitutes a strong password, one can take inspiration from tools like the Avast random password generator, which employs several factors to create strong passwords. These factors include:

  1. Capital Letters
  2. Lowercase Letters
  3. Digits
  4. Special Characters
  5. Length

The above-mentioned elements collectively contribute to a password's complexity, making it exponentially harder for malicious actors to guess or crack. Leveraging these components, we can develop an algorithm to gauge the strength of a password and ensure its resilience against various hacking methods. I mean Avast is a security software company, they should have more say on this than my grandma.

Let's dive in

Developing a Password Strength Algorithm with JavaScript

To implement a reliable password strength algorithm, we can draw insights from the provided JavaScript code snippet below. This snippet utilizes Vue.js to create an interactive interface that assesses the strength of a given password. The algorithm considers factors such as the presence of capital letters, digits, lowercase letters, special characters, and the overall length of the password.

The algorithm classifies passwords into four categories based on their strength:

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  1. Too Weak
  2. Could be Stronger
  3. Strong Password
  4. Very Strong Password

The strength assessment is dynamic and is updated in real-time as the user types. The algorithm ensures that the password meets certain requirements, including a minimum length threshold, before even considering its other characteristics. This approach promotes a well-rounded password that is not solely dependent on complexity, but also on essential aspects like length.

The provided code is a Vue.js component that aims to assess the strength of a password entered by a user and display a visual indication of the password's strength. It utilizes regular expressions to analyze various aspects of the password and then provides feedback on its strength. Let's break down the different parts of the code:

1. Imports and Setup: The script starts by importing necessary functions from the Vue.js library (`ref` and `watch`) and sets up a reactive variable called `password` and a reference to the password strength container.

2. Watch for Password Changes: The code uses the `watch` function to monitor changes to the `password` variable. Whenever the password value changes, the `StrengthChecker` function is called to assess the password strength.

3. StrengthChecker Function: This function takes the user's password as a parameter and is responsible for determining the strength of the password based on various criteria.

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   - The function starts by obtaining a reference to the nodes inside the password strength container.
   - It then clears any existing strength messages and resets the background colors of the strength indicator bars.
   - The function checks if the provided password is not empty.
   - It calls the `useAnalyzeRegex` function to analyze the password using a regular expression.
   - Depending on the strength level determined by the analysis, the function updates the strength message and applies appropriate styling to the indicator bars.

4. useAnalyzeRegex Function: This function takes a password string as input and analyzes it using regular expressions to determine its strength based on the presence of different character types (capital letters, digits, lowercase letters, and special characters).

   - The function initializes a `matches` object to keep track of the counts of different character types and an initial `strength` value.
   - It defines a regular expression `regexExpression` that matches alphanumeric characters and common special characters.
   - It uses the regular expression to find matches in the password string and then iterates over these matches to classify characters into different categories.
   - The `sumStrength` variable is calculated by counting the number of non-zero character type counts.
   - If the password length is less than 6 characters, the strength is set to 1 (very weak password).
   - Finally, the `matches.strength` value is set to `sumStrength`, and the function returns the `matches` object.

5. Template: The template section of the component contains an input field where users can enter their password. Below the input field is a password strength container that consists of four rounded bars and a text span for displaying strength messages.

6. CSS Classes: The code uses CSS classes to indicate the strength of the password visually. It adds the class `!bg-black` to the appropriate indicator bar based on the password strength determined by the `StrengthChecker` function.

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Our final results will look like the the image below:

Password strength JavaScript

In summary, the solution above is designed to provide real-time feedback to users as they type a password, indicating its strength based on the presence of different character types. The strength is assessed using a combination of regular expressions and character type counts. The visual representation of the strength is reflected in the background color of the indicator bars in the password strength container.


The digital landscape is rife with security challenges, and safeguarding sensitive information demands a proactive approach. While implementing various cybersecurity measures is essential, using complex passwords remains a cornerstone of online security.

By incorporating elements such as capital letters, lowercase letters, digits, special characters, and an optimal length, individuals can thwart common hacking methods like brute force and dictionary attacks. The provided JavaScript code snippet illustrates how an algorithm can dynamically evaluate password strength, helping users create robust defenses against potential cyber threats. As we navigate the ever-evolving world of technology, prioritizing strong passwords is a simple yet potent way to fortify our online presence and protect our valuable data.

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