How to remove all Non-ASCII characters from the string using JavaScript ?

In this article, we are given a string containing some Non-ASCII characters and the task is to remove all Non-ASCII characters from the given string. There are two methods to solve this problem which are discussed below: 

Approaches to remove all Nom-ASCII Characters from String:

• using ASCII values in JavaScript regEx
• using Unicode in JavaScript regEx
• using ASCII values with Array filter method

Approach 1: Using ASCII values in JavaScript regEx

• This approach uses a Regular Expression to remove the Non-ASCII characters from the string.
• Only characters that have values from zero to 127 are valid. (0x7F is 127 in hex).
• Use the .replace() method to replace the Non-ASCII characters with the empty string.

Example: This example implements the above approach. 

Javascript

// Input String
let str = "Hidd©©©en??Ascii ©©®®®Charac££ter";
// Display input string
console.log(str);

// Function to remove ASCII characters
// and display the output
function gfg_Run() {

    // Using RegEx and replace method
    // with Ascii values
    str = str.replace(/[^\x00-\x7F]/g, "");

    // Display output
    console.log(str);
}

// Funcion call
gfg_Run();

Output

Hidd©©©en??Ascii ©©®®®Charac££ter
Hidden??Ascii Character

Approach 2: Using Unicode in JavaScript regEx

• This approach uses a Regular Expression to remove the Non-ASCII characters from the string like in the previous example.
• It specifies the Unicode for the characters to remove. The range of characters between (0080 – FFFF) is removed.
• Use .replace() method to replace the Non-ASCII characters with the empty string.

Example: This example implements the above approach. 

Javascript

// Input String
let str = "Hidd©©©en??Ascii ©©®®®Charac££ter";
// Display input string
console.log(str);

// Function to remove ASCII characters
// and display the output
function gfg_Run() {

    // Using RegEx and replace method with Unicodes
    str = str.replace(/[\u{0080}-\u{FFFF}]/gu, "");

    // Display output
    console.log(str);
}

// Funcion call
gfg_Run();

Output

Hidd©©©en??Ascii ©©®®®Charac££ter
Hidden??Ascii Character

Approach 3: Using ASCII values with the Array filter method

This approach uses the Array filter along with the JavaScript split method to filter out the ASCII-valid characters from the input string.

Example: This example demonstrates the above approach.

Javascript

// Input String
let str = "Hidd©©©en??Ascii ©©®®®Charac££ter";
// Display input string
console.log(str);

// Funciot to remove ASCII characters
// and display the output
function gfg_Run() {

    // Using array.filter with ASCII values
    str = str
    .split("")
    .filter(function (char) {
      return char.charCodeAt(0) <= 127;
    })
    .join("");

    // Display output
    console.log(str);
}

// Funcion call
gfg_Run();

Output

Hidd©©©en??Ascii ©©®®®Charac££ter
Hidden??Ascii Character