Using Phone Number Look up Free to Autofill Web Forms

by | Aug 16, 2023

Today, businesses can face many situations that can create data vulnerabilities. Data vulnerability is when unauthorized persons access data due to security gaps or especially errors in computer systems or software. Businesses generally aim to prevent such important situations without experiencing data loss. Many businesses integrate phone number lookup web services into their applications as the first and simplest step to prevent data compromise. In particular, they integrate a phone number look up free service. They first test the limits and usage of the free phone number lookup APIs and then switch to the paid version.

A free phone number lookup API does not only provide phone number verification services to businesses. In fact, businesses use this API for many purposes. Today, there are not many good phone number lookup APIs to meet the needs of businesses. In this article, we will first discuss the importance of reverse phone number look up. Then we will introduce the most popular phone number look up API that many businesses prefer today, and we will realize the most common use case with this API.

What is the Importance of the Reverse Phone Number Lookup?

Reverse phone number lookup is a very popular process performed with a reverse phone lookup tool. With this tool, businesses can get detailed information about the phone numbers they want. This information is very important as they use it for many purposes. Some of the use cases that businesses perform with this data are as follows:

  • Obtaining User Information Automatically: This use case is the most common. With this use case, businesses can access detailed information from the phone numbers of their users. For example, in a web application’s user registration process, the user’s country and location are obtained from a reverse phone number lookup tool.
  • Number Verification: It is also very popular for businesses to use this API as number verification for data security. In particular, businesses validate the user’s phone number before sending or emailing sensitive information to the user’s phone number.
  • Extra Cost Prevention: With a reverse phone lookup service, businesses can easily reduce their costs such as calling or sending SMS. With this service, businesses can detect non-valid cell phone numbers in bulk SMS sending and not send SMS to those cell phones.

The numverify API: The Best Phone Number Look Up Free Web Service

home page of the numverify phone number look up free web service

The numverify API is one of the most popular reverse phone lookup sites on the market today. It supports phone numbers from 232 countries and is actively used by major companies such as Huawei and HomeAdvisor.

The main reason why the numverify API is known as the best reverse phone lookup API is the high accuracy of the data it provides. It processes phone numbers from 232 countries in real-time and cross-checks them against the latest international numbering plan databases. The response it provides to its users is also very detailed. It provides useful information about a phone number such as country prefix, country name, country code, location, carrier, and line type.

Discover all the differences between the numverify API and!

Finally, this API offers an incredible dashboard to its users. With this dashboard, users can track their API usage on a daily or monthly basis. They even receive automatic notifications if their API usage decreases.

What are the Subscription Plans of the numverify Free Reverse Phone Lookup API?

One of the most important features of the numverify API is its pricing policy. It is one of the free reverse phone lookups on the market.

The numverify API has one free subscription plan with a low usage limit. This free plan is limited to 1,000 API calls per month. In addition, this plan does not include any technical support and is not available in HTTPS.

The numverify API has three paid subscription plans. With these plans, users can choose between flexible and high-limit plans depending on the size of their project. The basic paid plan charges users $14.99 for 5,000 API calls per month. The most comprehensive paid plan is only $129.99 for 250,000 API calls per month. The numverify paid plans all offer standard technical support and HTTPS connectivity.

How to Use the numverify Phone Number Look Up Free API to Autofill Web Forms?

In this section, we will see how to autofill web form fields with the numverify API, the best phone number lookup free API today. Autofilling web form fields automatically is the most popular use case today. This is a method that directly increases the user experience. In this way, users do not waste much time on operations such as use registration.

We will develop this application step by step using HTML, CSS, JavaScript, and Bootstrap.

Learn how to build a phone validator app using the numverify API with PHP!

Get a Free API Key

Before we start developing the application, we need an API key to use the numverify API. For this, let’s press the ‘Sign Up’ button under the free plan, among the flexible plans offered by the numverify API, and get our API key by registering without any credit card information.

subscription plans of the numverify phone number look up free web service

After registration, we can see the API key obtained from the ‘Dashboard’ page, along with our API usage information.


In this step, we can start developing the codes of our application. For this, first of all, let’s create a file named ‘autofill-web-forms-with-numverify.html’ in the file path where we will develop the application. Then let’s put the following codes in this file.

<!DOCTYPE html>
<html lang="en">
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Autofill Web Forms App</title>
  <link rel="stylesheet" href="">
    body {
      background-color: #f8f9fa;
    .container {
      margin-top: 50px;
  <div class="container">
    <div class="row justify-content-center">
      <div class="col-md-6">
        <h2 class="mb-4">User Registration</h2>
        <form id="verificationForm">
          <div class="form-group">
            <label for="firstName">First Name:</label>
            <input type="text" class="form-control" id="firstName" required>
          <div class="form-group">
            <label for="lastName">Last Name:</label>
            <input type="text" class="form-control" id="lastName" required>
          <div class="form-group">
            <label for="phoneNumber">Phone Number:</label>
            <input type="tel" class="form-control" id="phoneNumber" required>
          <button type="button" class="btn btn-primary" id="continueBtn">Continue</button>

  <div class="container mt-5 d-none" id="registrationForm">
      <div class="form-group">
        <label for="location">Location:</label>
        <input type="text" class="form-control" id="location">
      <div class="form-group">
        <label for="countryName">Country Name:</label>
        <input type="text" class="form-control" id="countryName">
      <div class="form-group">
        <label for="countryCode">Country Code:</label>
        <input type="text" class="form-control" id="countryCode">
      <div class="form-group">
        <label for="lineType">Line Type:</label>
        <input type="text" class="form-control" id="lineType">
      <button type="button" class="btn btn-success">Save</button>

    document.getElementById('continueBtn').addEventListener('click', function () {
      const firstName = document.getElementById('firstName').value;
      const lastName = document.getElementById('lastName').value;
      const phoneNumber = document.getElementById('phoneNumber').value;

        .then(response => response.json())
        .then(data => {
          document.getElementById('location').value = data.location;
          document.getElementById('countryName').value = data.country_name;
          document.getElementById('countryCode').value = data.country_prefix;
          document.getElementById('lineType').value = data.line_type;
        .catch(error => {
          console.error('Error fetching data:', error);
          alert('An error occurred during phone number validation. Please try again.');

When we run the application with this code, we will get the user’s name, surname, and phone number information from the user at the user registration stage. After entering this information, the user will press the ‘Continue’ button and will see that the fields in the other form that opens are automatically filled.

Before running the application, let’s write our own API key in the ‘YOUR-API-KEY’ field and start the application.


When we run the application, the following default form will meet us.

default form of the user registration app

Let’s fill out the form on this page according to the user registration process.

completed form of the user registration app

After pressing the ‘Continue’ button, we see that the fields such as location, country name, country code, and line type are automatically filled in the new form opened. In this way, the user did not waste extra time to enter this information.

auto-filled form of the user registration app


The phone number lookup service is known as an effective tool for auto-filling web forms. It is of great importance to businesses. It provides a personal and effective service to users by increasing user satisfaction. It’s also a valuable resource for detecting spam and scam calls, keeping customer data up-to-date and complete, and optimizing marketing strategies. An accurate and reliable phone number lookup service helps businesses run a more efficient business process.

Use the best phone number lookup API of 2023 and get detailed information on phone numbers of 232 countries in JSON format!


Q: Does the numverify API Provide a Comprehensive Reverse Phone Lookup Site?

A: Yes, the numverify API provides users with the best phone number lookup site. It provides information on the phone numbers of 232 countries to its users with high accuracy and speed. Also, its unique documentation contains many detailed information for phone number lookup.

Q: What are the Differences Between the numverify API and Other Reverse Phone Lookup Services?

A: The numverify API has many important features that distinguish it from its competitors. First of all, it supports phone numbers from more than 230 countries. It then provides fields such as line type, carrier, country name, and country code for valid phone numbers. Finally, it has a free subscription plan and this plan is limited to 1,000 API calls per month.

Q: Is numverify a Phone Number Look Up Free API?

A: Yes, it is. The numverify API has multiple subscription plans. The first one is the free plan. It does not require any credit card information to sign up for that free plan. The monthly limit for the free plan is 1,000 API calls.

Q: What are the Best Use Cases of the numverify API?

A: Some popular use cases of the numverify API are as follows:

  • Phone Number Verification
  • Autofill WebForms
  • Spam Detection
  • Analysis and Marketing
  • Developing Marketing Strategies