Thermometer Slider Widget Using JavaScript

This code creates a thermometer slider widget using JavaScript. It lets you adjust temperature ranges visually. The slider modifies temperature values between -20°C to 50°C or Fahrenheit. You can change the temperature units between Celsius and Fahrenheit. Adjust the slider or click on the temperature values to modify them easily.

This code for a thermometer slider widget is handy for websites needing temperature adjustment tools. It’s useful for weather apps, climate-related sites, or any platform requiring temperature settings. One major benefit is its intuitive visual interface for easy temperature control.

How to Create a Thermometer Slider Widget Using JavaScript

1. Start by creating the HTML structure. Copy the following code within the <div id="wrapper"> tags. This includes the thermometer container, temperature slider, input fields, and information paragraph.

<div id="wrapper">	
	<div id="termometer">
		<div id="temperature" style="height:0" data-value="0°C"></div>
		<div id="graduations"></div>
	</div>
	
	<div id="playground">		
		<div id="range">
			<input id="minTemp" type="text" value="-20">
			<input type="range" min="-20" max="50" value="42">
			<input id="maxTemp" type="text" value="50">
		</div>
		<p id="unit">Celcius C°</p>
	</div>
	
	<p id="info">Click on the values to change them!</p>
</div>

2. Copy the following CSS code to style the thermometer and its components. This code ensures a visually appealing and responsive design. You can customize colors and dimensions to match your website’s theme.

@import url("https://fonts.googleapis.com/css?family=Jaldi&display=swap");
body {
  display: flex;
  height: 100vh;
  margin: 0;
  font-family: "Jaldi", sans-serif;
  font-size: 14px;
}

#wrapper {
  margin: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}

p {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

#info {
  opacity: 0.2;
  margin: 0;
  text-align: center;
}

#termometer {
  width: 25px;
  background: #38383f;
  height: 240px;
  position: relative;
  border: 9px solid #2a2a2e;
  border-radius: 20px;
  z-index: 1;
  margin-bottom: 50px;
}
#termometer:before, #termometer:after {
  position: absolute;
  content: "";
  border-radius: 50%;
}
#termometer:before {
  width: 100%;
  height: 34px;
  bottom: 9px;
  background: #38383f;
  z-index: -1;
}
#termometer:after {
  transform: translateX(-50%);
  width: 50px;
  height: 50px;
  background-color: #3dcadf;
  bottom: -41px;
  border: 9px solid #2a2a2e;
  z-index: -3;
  left: 50%;
}
#termometer #graduations {
  height: 59%;
  top: 20%;
  width: 50%;
}
#termometer #graduations, #termometer #graduations:before {
  position: absolute;
  border-top: 2px solid rgba(0, 0, 0, 0.5);
  border-bottom: 2px solid rgba(0, 0, 0, 0.5);
}
#termometer #graduations:before {
  content: "";
  height: 34%;
  width: 100%;
  top: 32%;
}
#termometer #temperature {
  bottom: 0;
  background: linear-gradient(#f17a65, #3dcadf) no-repeat bottom;
  width: 100%;
  border-radius: 20px;
  background-size: 100% 240px;
  transition: all 0.2s ease-in-out;
}
#termometer #temperature, #termometer #temperature:before, #termometer #temperature:after {
  position: absolute;
}
#termometer #temperature:before {
  content: attr(data-value);
  background: rgba(0, 0, 0, 0.7);
  color: white;
  z-index: 2;
  padding: 5px 10px;
  border-radius: 5px;
  font-size: 1em;
  line-height: 1;
  transform: translateY(50%);
  left: calc(100% + 1em / 1.5);
  top: calc(-1em + 5px - 5px * 2);
}
#termometer #temperature:after {
  content: "";
  border-top: 0.4545454545em solid transparent;
  border-bottom: 0.4545454545em solid transparent;
  border-right: 0.6666666667em solid rgba(0, 0, 0, 0.7);
  left: 100%;
  top: calc(-1em / 2.2 + 5px);
}

#playground {
  font-size: 1.1em;
}
#playground #range {
  display: flex;
}
#playground #range input[type=text] {
  width: 2em;
  background: transparent;
  border: none;
  color: inherit;
  font: inherit;
  margin: 0 5px;
  padding: 0px 5px;
  border-bottom: 2px solid transparent;
  transition: all 0.2s ease-in-out;
}
#playground #range input[type=text]:focus {
  border-color: #3dcadf;
  outline: none;
}
#playground #range input[type=text]:first-child {
  text-align: right;
}
#playground #unit {
  width: 100%;
  margin: 0;
  text-align: center;
}
#playground #unit:hover {
  cursor: pointer;
}

input[type=range] {
  -webkit-appearance: none;
  background: transparent;
  margin: 5.5px 0;
  width: 100%;
}
input[type=range]::-moz-focus-outer {
  border: 0;
}
input[type=range]:hover {
  cursor: pointer;
}
input[type=range]:focus {
  outline: 0;
}
input[type=range]:focus::-webkit-slider-runnable-track {
  background: #313137;
  border-color: #313137;
}
input[type=range]:focus::-ms-fill-lower {
  background: #2a2a2e;
}
input[type=range]:focus::-ms-fill-upper {
  background: #313137;
  border-color: #313137;
}
input[type=range]::-webkit-slider-runnable-track {
  cursor: default;
  height: 10px;
  transition: all 0.2s ease;
  width: 100%;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  box-shadow: 1px 1px 1px transparent, 0 0 1px rgba(13, 13, 13, 0);
  background: #2a2a2e;
  border: 2px solid #2a2a2e;
  border-radius: 5px;
}
input[type=range]::-webkit-slider-thumb {
  box-shadow: 4px 4px 4px transparent, 0 0 4px rgba(13, 13, 13, 0);
  background: #3dcadf;
  border: 0px solid #3d3d44;
  border-radius: 12px;
  cursor: pointer;
  height: 11px;
  width: 18px;
  -webkit-appearance: none;
  margin-top: -2.5px;
}
input[type=range]::-moz-range-track {
  box-shadow: 1px 1px 1px transparent, 0 0 1px rgba(13, 13, 13, 0);
  cursor: default;
  height: 10px;
  transition: all 0.2s ease;
  width: 100%;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  background: #2a2a2e;
  border: 2px solid #2a2a2e;
  border-radius: 5px;
  height: 5px;
}
input[type=range]::-moz-range-thumb {
  box-shadow: 4px 4px 4px transparent, 0 0 4px rgba(13, 13, 13, 0);
  background: #3dcadf;
  border: 0px solid #3d3d44;
  border-radius: 12px;
  cursor: pointer;
  height: 7px;
  width: 14px;
}
input[type=range]::-ms-track {
  cursor: default;
  height: 10px;
  transition: all 0.2s ease;
  width: 100%;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  background: transparent;
  border-color: transparent;
  border-width: 5.5px 0;
  color: transparent;
}
input[type=range]::-ms-fill-lower {
  box-shadow: 1px 1px 1px transparent, 0 0 1px rgba(13, 13, 13, 0);
  background: #222226;
  border: 2px solid #2a2a2e;
  border-radius: 10px;
}
input[type=range]::-ms-fill-upper {
  box-shadow: 1px 1px 1px transparent, 0 0 1px rgba(13, 13, 13, 0);
  background: #2a2a2e;
  border: 2px solid #2a2a2e;
  border-radius: 10px;
}
input[type=range]::-ms-thumb {
  box-shadow: 4px 4px 4px transparent, 0 0 4px rgba(13, 13, 13, 0);
  background: #3dcadf;
  border: 0px solid #3d3d44;
  border-radius: 12px;
  cursor: pointer;
  height: 7px;
  width: 14px;
  margin-top: 2.5px;
}
input[type=range]:disabled::-webkit-slider-thumb {
  cursor: not-allowed;
}
input[type=range]:disabled::-moz-range-thumb {
  cursor: not-allowed;
}
input[type=range]:disabled::-ms-thumb {
  cursor: not-allowed;
}
input[type=range]:disabled::-webkit-slider-runnable-track {
  cursor: not-allowed;
}
input[type=range]:disabled::-ms-fill-lower {
  cursor: not-allowed;
}
input[type=range]:disabled::-ms-fill-upper {
  cursor: not-allowed;
}

3. Finally, copy the JavaScript code. This code enables dynamic temperature adjustments and unit switching. It calculates the temperature’s visual representation based on the slider’s position.

const units = {
  Celcius: "°C",
  Fahrenheit: "°F" };


const config = {
  minTemp: -20,
  maxTemp: 50,
  unit: "Celcius" };


// Change min and max temperature values

const tempValueInputs = document.querySelectorAll("input[type='text']");

tempValueInputs.forEach(input => {
  input.addEventListener("change", event => {
    const newValue = event.target.value;

    if (isNaN(newValue)) {
      return input.value = config[input.id];
    } else {
      config[input.id] = input.value;
      range[input.id.slice(0, 3)] = config[input.id]; // Update range
      return setTemperature(); // Update temperature
    }
  });
});

// Switch unit of temperature

const unitP = document.getElementById("unit");

unitP.addEventListener("click", () => {
  config.unit = config.unit === "Celcius" ? "Fahrenheit" : "Celcius";
  unitP.innerHTML = config.unit + ' ' + units[config.unit];
  return setTemperature();
});

// Change temperature

const range = document.querySelector("input[type='range']");
const temperature = document.getElementById("temperature");

function setTemperature() {
  temperature.style.height = (range.value - config.minTemp) / (config.maxTemp - config.minTemp) * 100 + "%";
  temperature.dataset.value = range.value + units[config.unit];
}

range.addEventListener("input", setTemperature);
setTimeout(setTemperature, 1000);

That’s all! hopefully, you have successfully created the Thermometer Slider Widget Using JavaScript. If you have any questions or suggestions, feel free to comment below.

Asif Mughal

I code and create web elements for amazing people around the world. I like work with new people. New people new Experiences.
I truly enjoy what I’m doing, which makes me more passionate about web development and coding. I am always ready to do challenging tasks whether it is about creating a custom CMS from scratch or customizing an existing system.