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Octavalidate - JS V1.3.2 Verified on Openbase

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This JavaScript library helps to validate your frontend (HTML) forms using validation rules, sophisticated regular expressions and form input attributes.

We have included a demo.html file which you can play with to see how this library really works.

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Octavalidate - ReactJS

Use the ReactJS release of this library to validate your front-end forms client-side.

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Octavalidate - PHP

Use the PHP release of this library to validate your forms server-side.

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Octavalidate - NodeJS

Use the NodeJS release of this library to validate your forms server-side.

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Visit the DOCUMENTATION to learn more about this GREAT Library!



Place this script before the </head> tag.

<script src=""></script>


React JS

Visit this Link to the Documentation to learn how you can install & use this Library in React JS.

How to Use

Create a form tag with input elements and set the attribute octavalidate with a list of validation rules on the form input(s) that you want to validate.

<form id="form_register">

    <input id="inp_email" name="email" type="email" octavalidate="R,EMAIL">

    <input id="inp_age" name="age" type="number" octavalidate="R,DIGITS">

    <button type="submit">submit</button>


Make sure that all input elements have a unique identifier.

Now you need to create a new instance of the function and pass in the form id as the first argument, and any configuration options as the second argument.

Then begin validation on that particular form by invoking the validate() method.

It is recommended to invoke the validate() method when the form is submitted.

The return type of the validate() method is Boolean.

//create new instance of the function
const myForm = new octaValidate('FORM_ID');
//listen for submit event
document.getElementById('FORM_ID').addEventListener('submit', function(e){
    //invoke the method
    if(myForm.validate() === true)
      //validation successful
      //process form data here
    } else {
      //validation failed


Here is the list of default validation rules.

Can’t see a validation rule that you need for your form? Don’t worry!

With octaValidate, you have the power to define a custom rule and it will be processed as if it were a default rule.


In some cases where you need a custom rule, use the method below to define one for your form.

//syntax for custom rule

Here’s a custom rule to validate an email address.

//custom email validation
const rule_title = "EML";
const reg_exp = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
const err_txt = "Please povide a valid Email Address";
//create new instance of the function
const myForm = new octaValidate('form_register');
//define the custom rule
myForm.customRule(rule_title, reg_exp, err_txt);

Then on your Input Element, provide the rule title [ EML ].

<input type="email" id="inp_email" octavalidate="EML">

Note: All Rule Titles are case-sensitive!


What if you want to define more validation rules?

All you need to do is to create an object with your validation rule, regular expression and error text separated by a comma, then invoke the moreCustomRules() method.

var rules = {
    "EML": [/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/, "A Valid email address is required"],
    "URI": [/^((?:http:\/\/)|(?:https:\/\/))(www.)?((?:[a-zA-Z0-9]+\.[a-z]{3})|(?:\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1(?::\d+)?))([\/a-zA-Z0-9\.]*)$/i, "Please provide a valid URL"]

//create new instance of the function
const myForm = new octaValidate('form_register');
//define more custom rules

Note: You do not need to pass in your regular expression as a string! This is because the JavaScript engine natively recognizes regular expressions.


We’ve added an extra attribute that will enable you to provide your custom error message incase a validation fails.

The table below shows the default validation rules and their attibutes for a custom error message.

Validation Rule Description Validation Text Attribute
R Required ov-required-msg
EMAIL EMAIL ov-email-msg
ALPHA_ONLY Alphabets Only ov-alpha-only-msg
ALPHA_SPACES Alphabets and Spaces ov-alpha-spaces-msg
ALPHA_NUMERIC Alphabets with Numbers ov-alpha-numeric-msg
LOWER ALPHA Lowercase letters ov-lower-alpha-msg
UPPER_ALPHA Uppercase letters ov-upper-alpha-msg
PWD Password ov-pwd-msg
DIGITS Digits ov-digits-msg
URL URL ov-url-msg
URL_QP URL with Query Parameters ov-url-qp-msg
DATE_MDY Date in the format MM/DD/YYYY ov-date-mdy-msg
USERNAME Username ov-username-msg
TEXT General Text ov-text-msg

Here’s how to use the custom error message

<input type="text" octavalidate="R,USERNAME" ov-required-msg="Your username is required" ov-username-msg="Username should contain letters or numbers" name="username" id="inp_uname">

The R validation rule validates a CHECKBOX, FILE INPUT ELEMENT, or a TEXT input by marking them as required fields and you may provide a custom validation error text using the attribute ov-required-msg.


Currently we have 4 attributes validation:

You can validate: maxlength, minlength and length by providing it as an attribute to the form input.

<input type="text" id="inp_maxlength" maxlength="5">

<input type="text" id="inp_minlength" minlength="5">

<input type="text" id="inp_length" length="5">


You can check if two inputs contain the same values, using the attribute equalto on the input element, with a value containing the ID of the other input element to check against.

<input type="password" id="inp_pwd1" octavalidate="R,PWD" ov-required-msg="Your Password is required">
<!--check if both values match -->
<input type="password" id="inp_pwd2" equalto="inp_pwd1" ov-equalto-msg="Both passwords do not match">


You can validate: accept, accept-mime, size, minsize, maxsize by providing it as an attribute to the file input element.

Please refer to the documentation to learn more about file validation.


You can validate a range of numbers using this attribute. Say I want a user to provide a number between 1 to 5, I will set up the validation like this on my input element

<input type="text" id="inp_range" range="1 - 5">



Invoke the status() method anytime to check the number of validation errors present on the form.

//Your validation instance
const myForm = new octaValidate('form_register');
//check validation errors


You can define a function that will execute if there are validation errors or a function that will execute if there are no validation errors.

To define a callback, invoke the method below then pass in your function as an argument.

//create new instance of the function
const myForm = new octaValidate('form_register');
//success callback
let successCB = function(){
    alert("No validation error");
//error callback
let errorCB = function(){
    alert(myForm.status()+" validation error(s)")
//invoke the method
myForm.validateCallBack(successCB, errorCB);

If there are no validation errors, successCB will be executed but if there are validation errors, the errorCB will be executed.

Note: This callback feature will only work if validation has started on the form. Make sure to start validating the form by invoking the validate() method when the form is being submitted.


We have 3 configuration options:

To use any of these options, provide it as an object and pass it as the second argument when creating an instance of octaValidate.

//config options
const options = {
  strictMode : true, 
  strictWords : ["error", "false", "invalid", "fake", "admin"],
  errorElem : {
//my function instance
const myForm = new octaValidate('FORM_ID', options);


After creating an instance of the function, the methods below becomes available for use.

//create instance of the function
const myForm = new octaValidate('FORM_ID');

There are more methods in the documentation, please visit the documentation to learn more.


Do you need a detailed explanation on how to use this library? Read the article on Medium




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