RGB To HEX / Hex To RGB Converter Using Javascript

Hello Everyone, In this tutorial we are going to create an RGB to HEX and HEX to RGB converter using Javascript. There are many rgb to hex converter tools using js are available but today let us make this tool ourselves with HTML, CSS and Vanilla Javascript. This is a great project for javascript intermediates. In this converter tool consists of two input fields. One for RGB and another one for Hex. If the user wants to convert his RGB colour code into HEX code, he needs to enter the colour value in the RGB field and the HEX equivalent will be displayed in the other field. Similarly, for Hex to RGB conversion the user has to enter the colour code in the HEX field and output will be displayed in the RGB field. So this is All in one RGB to HEX and HEX to RGB converter tool.


Copy - Paste the html code below into your HTML file. We start the HTML code by create a container div. Inside this container are two wrapper. Each of the wrappers encloses a label and an input field. The first label is for the RGB field while the second is for the HEX field.

<!DOCTYPE html>
<html lang="en">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>RGB-Hex Converter | Codegyan</title>
    <!--Google Font-->
    <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@400;600&display=swap" rel="stylesheet">
    <link rel="stylesheet" href="style.css">
    <div class="container">
        <div class="wrapper">
            <label for="rgb">RGB</label>
            <input type="text" id="rgb" oninput="toHex()" placeholder="Enter RGB Value">
        <div class="wrapper">
            <label for="hex">HEX</label>
            <input type="text" id="hex" oninput="toRgb()" placeholder="Enter Hex Value">
    <script src="script.js"></script>


Next, You have to paste the code provide below into the style.css file. We do a regular CSS reset by removing the default margins and paddings of all the elements. Next we add #976efa colour to the document body. After that we have add css for container div. We place and arrange the wrapper by using the flex layout. We use the flex-wrap property to make it responsive.

    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: "Poppins",sans-serif;
    width: 100%;
    background-color: #976efa;
    background-color: #ffffff;
    width: 80vmin;
    min-width: 250px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 50px;
    position: absolute;
    transform: translate(-50%,-50%);
    top: 50%;
    left: 50%;
    padding: 50px 10px;
    border-radius: 5px;
    width: 230px;
    font-weight: 600;
    width: 100%;
    padding: 5px 0;
    outline: none;
    border: none;
    border-bottom: 2px solid #404050;
    font-size: 20px;
    font-weight: 400;
    margin-top: 5px;


Lastly, we add functionality to this converter tool using javascript. You have to Copy Paste the code below into your script.js file. On window load, we clear both the input fields. When the user inputs something in the Hex field, the toRGB() is called. First the input from the input field is validated. If the input is invalid the invalid() is called.

Regular Expressions:

^#{0,1}: 0 or 1 # in the start(i.e # is optional). [A-Fa-f0-9]{6}$: 6 characters from A to F or a to f or any number till the end of the input. The user can either use the format with ‘#’ or no ‘#’ for the HEX Code. That is both ‘2345ac’ and ‘#2345ac’ are valid. The parseInt(value,16) would convert the hexadecimal input to number.

let hexInput = document.getElementById("hex");
let rgbInput = document.getElementById("rgb");

    hexInput.value = "";
    rgbInput.value = "";

function valid(element){
    element.style.color = "#202040";

function invalid(element,otherElement){
    element.style.color = "#f04624";
    otherElement.value = 0;

function toRgb(){
    let hexCode = hexInput.value;
    let rgbArr = [];
        hexCode = hexCode.split("#")[1] || hexCode;
        for(let i=0; i<hexCode.length;i+=2){
            rgbArr.push(parseInt(hexCode[i] + hexCode[i+1], 16));
        rgbInput.value = "rgb(" + rgbArr + ")";
        document.body.style.backgroundColor = "rgb(" + rgbArr + ")";

When the user enters the colour code in the RGB field, the toHex() is called. This function first validates the input code using the regular expressions.

Regular Expressions:

^rgb\(: Start with ‘rgb(‘. [0-9]{1,3},[0-9]{1,3},[0-9]{1,3}: Three values seperated by commas.Each value would be 1/2/3 digit. \)$: ends with ‘)’.

function toHex(){
    let rgbCode = rgbInput.value;
    let rgbRegex1 = /^rgb\([0-9]{1,3},[0-9]{1,3},[0-9]{1,3}\)$/;
    let rgbRegex2 = /^[0-9]{1,3},[0-9]{1,3},[0-9]{1,3}$/
    let hex = "#";
    if(rgbRegex1.test(rgbCode) || rgbRegex2.test(rgbCode)){
        rgbCode = rgbCode.replace(/[rgb()]+/g,"") || rgbCode;
        rgbCode = rgbCode.split(",");
        let condition = rgbCode.every((value) => {
            return parseInt(value) <= 255;
            rgbCode.forEach(value => {
                value = parseInt(value).toString(16);
                hex += value.length == 1? "0"+value : value;
            hexInput.value = hex;
            document.body.style.backgroundColor = hex;

Also Read : How To Create Minion Eyes That Follows Mouse Cursor

If you wann to check the demo of this code, then you can check using below demo button.

Click on the following download button to download all source code files of converter tools directly on your computer.

Final Word

In this way, we can create rgb to hex converter tool using html, css & JavaScriptI hope you all like this tutorial. Keep with us for next tutorial. if you wann the source code of this code you can get this on our github account. If you have any query please free to contact us Or comment below.