clearout
  • Products
    • ProspectSQL/MQL list building with high levels of personalization, real-time data enrichment and prospect search
    • Email FinderFind individual or bulk emails by entering the person & company name or domain
    • Email VerifierVerify emails addresses individually, in bulk or through API, with 99% accuracy
    • Clearout For SheetsVerify email addresses directly on Google Sheets with Clearout for sheets add-on
    • ClearoutPhoneValidate phone numbers across 240+ countries in bulk, quick or real time validation
  • Resource
      Support
    • Getting started
    • Developers
    • API
    • Email Verification API
    • Email Finder API
    • Blogs
    • Top 22 GoHighLevel Integrations to Improve Your Workflow in 2025
    • View All Blogs
    • Use cases
    • Lead Generation
    • Comparison Guide
    • Email Verification Tools
  • Pricing
  • Integrations
  • Enterprise
  • Login
Try it free Book a 1-to-1 demo
Aastha Shaw / October 27, 2023 March 14, 2025

Form Validation — Importance, Ways & Best Practices


Form Validation Guide: Best practices & ways to implement form validation

Have you ever tried filling out a form and not gotten the desired results?

Many forms are not designed properly, making the user feel lost or not knowing exactly what happened. This is where form validation comes into play.

It helps to design intuitive and responsive forms and tell the user precisely what went wrong. When forms are well-designed and simple, users are more likely to fill them out without any errors.

Form Validation Guide: Best practices & ways to implement form validation

So in this article, we will understand what form validation is, how to implement it, and review some form validation best practices guaranteed to increase sign-up form conversions.

Let’s begin!

Table of Contents


● What is Form Validation?
● Ways of Form Validation
● How to Implement Form Validation?
● Form Validation Errors To Avoid
● Form Validation Best Practices
● Get Started With Form Validation - The Right Way!

What is Form Validation?


Form validation is the process of making sure that the data submitted through web forms is accurate, consistent, and conforms to specific rules and requirements that are predefined. If these requirements are not met, or the data is not correctly filled out, the form data will not be accepted or stored on the server.

Since it stops users from filing wrong data or prevents malicious entities from filling in harmful code or viruses via forms, it acts as the first line of defense for businesses against erroneous data entry, malicious users, and spam.

Form validation covers a few fundamental aspects, including:

  • Data Accuracy: Form validation helps to ensure that the data collected from users is accurate and complete. This is important for businesses that rely on this data to make decisions.
  • Security: Form validation helps to prevent malicious users from submitting harmful data or code. This can help to protect your website and users from attacks.
  • User Experience: It can improve user experience by preventing users from submitting forms with errors or telling them exactly what needs to be fixed. This can save users time and frustration.

The form validation process also covers insights that help improve user interaction and enhance overall user experience. For example, if you have a product page and the user has to fill in a few details during checkout, form validation processes ensure this is error-free, simplified, and quick.

Form Validation Guide: Best practices & ways to implement form validation

Ways of Form Validation


The form validation process can be done using a variety of methods, but the most popular ones include:

1. Before Submission or Inline Validation


Before submission validation is performed on the user's device before the form is submitted. Since this type of submission happens as the user fills out the form, it is also known as inline validation. It is typically done using JavaScript.

Inline validation works by continuously monitoring user input. When a user enters data into a field, the validation process assesses that input against predefined rules or patterns. If the input is correct, no feedback is provided.

However, if there's an error, such as an invalid email address, the system immediately highlights the issue and provides feedback, often in the form of error messages.

This has great benefits for user experience, such as:

  • It prevents users from submitting forms with errors or wrong information.
  • Gives immediate feedback to users, making sure they rectify the mistake before proceeding with the form.
  • It is ideal to verify email addresses, matching passwords, dates, phone numbers, and other similar fields..

However, it lacks when it comes to more complex validation such as malicious code injection into forms.

2. After Submission Validation


After submission, validation processes all the data once the user submits the form. It is typically done using a programming language such as PHP or Python.

It examines the entire form, checking for errors, missing information, or invalid entries after the data is submitted. If any issues are identified, it generates error messages and provides feedback to the user. Users can then make corrections and resubmit the form.

Thus, the benefits of this methodology are:

  • It is more secure than inline validation..
  • It can validate complex data, such as uploaded files or code injections..
  • It can integrate with other systems, such as databases or payment processors.

However, it lacks user experience. It can lead to latency in the form submission process, as users only know what is wrong after they hit submit. It can also be a bit frustrating to go through the form again to find and fix the errors (especially if it is a long one).

Which Way is The Best Form Validation Method?


The best way to implement form validation is to look at the benefits of both methods and implement those that are ideal for your needs.

Since providing a good user experience is also very important for every business, we recommend-

✔️ Using inline validation on web forms ( like sign-ups, subscriptions, lead generation, etc.) to make it easy for the users.
✔️ Implementing after-submission form validation for payment pages that need better security.

How to Implement Form Validation?


1. Using JavaScript


To implement inline form validation using JavaScript, you will need to write some code to check the validity of the user input. This code can be as simple or as complex as you need it to be.

For example, the following code checks to make sure that a required field is not empty:

JavaScriptconst requiredField = document.getElementById("required-field"); if
(requiredField.value === "") { // Display an error message. }

Once you have written your validation code, add it to your form. You can do this by adding it to the section of your HTML document or by adding it to a JavaScript file and then referencing that file in the section of your HTML document.

2. Using Third-party Library


Several third-party libraries can be used to implement inline validation. These libraries typically provide a pre-written set of validation functions that you can use in your form.

One popular third-party library for inline form validation is jQuery Validate. To use jQuery Validate, you must include the jQuery and library on your web page. Then, you can use jQuery Validate to add validation to your form fields.

For example, the following code uses jQuery Validate to add validation to a required field:

JavaScript$(document).ready(function() { $("#required-field").validate({ required: true }); });

Once you have added validation to your form fields, you must submit the form using the submit() method. jQuery Validate will automatically validate the form fields before the form is submitted. JQuery Validate will display an error message if any form fields are invalid.

JavaScript$(document).ready(function() { $("#required-field").
validate({ required: true }); });

3. Using No-Code & Highly Accurate Options Like Clearout


You can use Clearout real-time validation for critical user information such as email address and phone number.

It is a no-code and easy-to-use solution as it integrates seamlessly with most web forms and applications. It offers plugins, widgets, and APIs that simplify the integration process, ensuring that your existing forms can benefit from inline validation without a hitch.

To use Clearout, you only have to add a few lines of code (provided by Clearout) to your HTML form, and it will start validating the form fields and displaying error messages if necessary.


👉 Learn about all clearout form integrations and how they work

Form Validation Errors To Avoid


There are a few things you should avoid when creating forms.

1. Too Many Fields & Information


Sometimes, designers and form creators tend to put in too much information, making the form seem complex. Ensure that the form is concise and that you provide only the relevant information.

Form Validation Guide: Best practices & ways to implement form validation

2. Generic Error Messages


When it comes to errors, it is important to tell users exactly what went wrong. Providing error messages that are vague, unhelpful, or overly technical can confuse users, leaving them unsure of how to correct their input.

Form Validation Guide: Best practices & ways to implement form validation

If the user fills out multiple incorrect fields, the form validation must clearly mention what went wrong and which fields require fixing. For example, if you have a B2B offering and want to set a requirement to allow only business emails, this can be easily achieved.

Form Validation Guide: Best practices & ways to implement form validation

With the 20+ validation checks and customizable settings offered by Clearout, you can allow specific addresses to enter your form, remove unwanted sub-addresses (Gmail, Yahoo, AOL, etc.), identify fake emails, and do much more to ensure good data quality.

3. Allow Users To Correct Their Mistakes


Once a user has made a mistake on your form, don't make them start over. Instead, allow them to correct their mistakes and submit the form. Starting from scratch, especially in a long-form, can be frustrating and off putting.

Form Validation Guide: Best practices & ways to implement form validation

Form Validation Best Practices


Every form is a chance to impress your users and showcase how your brand stands out from the rest. Here’s a cheat sheet to design forms that convert:

  1. Have clear headings and subheadings that clearly explain the purpose of the form and how it will be used.
  2. Divide long forms into sections and validate each section as users complete, reducing the chances of overwhelming users.
  3. If using CAPTCHA, opt for user-friendly alternatives that are less frustrating for users.
  4. Provide error messages that are easy to understand and clearly explain what went wrong.
  5. Optimize for mobile and other devices as more users access websites through smartphones.
  6. Test your form validation thoroughly before launching your website or application.

Get Started With Form Validation - The Right Way!


While designing forms, ensure the need is clear and you know what is expected. The ideal thought process should be to be concise, precise, empathetic, and flexible.

By following these tips and principles, your forms can be user-centric, making the entire form-filling experience seamless. With inline validation and advanced email verification processes, you can even fine-tune forms to be highly specific to your requirements.

Try Clearout Real-time Email Validation


Signup Now
Share this article

Recent Posts

23 May 2025
Top 22 GoHighLevel Integrations to Improve Your Workflow in 2025

Are you looking to boost your productivity with GHL? Here are top 22 GHL Integrations to streamline ...

22 May 2025
13 Best Lead Finder Tools in 2025 (Reviewed)

Explore the list of 13 best lead finders of 2025 to find high-quality leads. Learn more about their ...

20 May 2025
22 Effective Cold Email Templates That Get Replies in 2025

Going to hit send on that cold email? Before you do, check out these tips, tricks and perfectly cura ...

07 May 2025
Email Blast 2025: Best Bulk Email Sending Practices that work

Sending bulk emails in 2025? Learn best email blast practices with dos & don'ts to ensure your bulk ...

05 May 2025
13 Top Skrapp.io Alternatives Recommended in 2025

Looking for the best Skrapp.io alternatives in 2025? Explore this handpicked list of 13 tools to rea ...

Prospecting ,Email Finder & Email Verification Service

Prospecting ,Email Finder & Email Verification Service


Expand your reach by discovering and verifying the ideal prospects.

Sign up & get 100 free credits | No Credit Card required

Company

Why Clearout?

Pricing

Contact Us

Careers

Enterprise

Sitemap

FAQ

Products

Email Verifier

Email Finder

Prospect

LinkedIn Email Finder

Reverse Lookup

Google Sheets Add-on

WordPress Plugin

ClearoutPhone

What's New?

Resources

Integrations

HubSpot

Team Account

API

Compare Email Verifier

Compare Prospecting

Use Cases

Blog

Help

Legal

Privacy Policy

Terms

DPA

Security

Trust Center

Certification

ISO 27001/2022

SOC 2 Type 2

GDPR

Partnership

HubSpot Certified

Affiliates

Partners

Clearout for browser

⚡ Supercharge Your Prospect Research with Clearout's LinkedIn Chrome Extension - Find and Verify Emails with Confidence!

Clearout Chrome extension

clearout
© 2025 Clearout. All Rights Reserved. Powered by Clearout, LLC.
✨ New! Connect Kit to Clearout and verify subscribers with 99%+ accuracy. Try Now>>
X