When it comes to form validation, it’s hard to have a versatile solution that works with every form. Figuring out how to display errors is not a simple task. This is something I tried to remedy with this script. When an error needs to be displayed, the script creates a div and positions it in the top right corner of the input. This way you don’t have to worry about your HTML form structure. The rounded corner and shadow are done with CSS3 and degrade well in non compliant browsers. There is no images needed.

Download the source code View demo

Validations range from email, phone, url to more complex calls such as ajax processing.
Bundled in several locales, the error prompts can be translated in the locale of your choice.

**Important**: v2 is a significant rewrite of the original 1.7 branch. Please read the documentation as the API has changed! Also the documentation is always more up to date on the github README

Legacy 1.7 documentation and download can be found under package when you hit download on github


1. Unpack the archive
2. Include the script jquery.validationEngine.closure.js in your page
3. Pick the locale of the choice, include it in your page: jquery.validationEngine-XX.js
4. **Read this manual** and understand the API

Running the Demos

Most demos are functional by opening their respective HTML file. However, the Ajax demos require the use of Java6 to launch a lightweight http server.

1. Run the script `runDemo.bat` (Windows) or `runDemo.sh` (Unix) from the folder
2. Open a browser pointing at [http://localhost:9173](http://localhost:9173)


First link jQuery to the page

    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.js" type="text/javascript"></script>

Attach *jquery.validationEngine* and its locale

    <script src="js/jquery.validationEngine-en.js" type="text/javascript" charset="utf-8"></script>
    <script src="js/jquery.validationEngine.js" type="text/javascript" charset="utf-8"></script>

Finally link the desired theme

    <link rel="stylesheet" href="css/validationEngine.jquery.css" type="text/css"/>

Field validations

Validations are defined using the field’s **class** attribute. Here are a few examples showing how it happens:

    <input value="someone@nowhere.com" class="validate[required,custom[email]]" type="text" name="email" id="email" />
    <input value="2010-12-01" class="validate[required,custom[date]]" type="text" name="date" id="date" />
    <input value="too many spaces obviously" class="validate[required,custom[onlyLetterNumber]]" type="text" name="special" id="special" />

For more details about validators, please refer to the section below.


The validator is typically instantiated by using a call of the following form:

    $("#form.id").validationEngine(action or options);

The method takes one or several optional parameters, either an action (and parameters) or a list of options to customize the behavior of the engine.

Here comes a glimpse: say you have a form is this kind

    <form id="formID" method="post" action="submit.action">
        <input value="2010-12-01" class="validate[required,custom[date]]" type="text" name="date" id="date" />

The following code would instance the validation engine:




Initializes the engine with default settings

    $("#formID1").validationEngine({promptPosition : "centerRight", scroll: false});
    $("#formID1").validationEngine('init', {promptPosition : "centerRight", scroll: false});
Attaches jQuery.validationEngine to form.submit and field.blur events.
<pre lang="html">
Unregisters any bindings that may point to jQuery.validaitonEngine.
<pre lang="html">


Validates the form and displays prompts accordingly. Returns *true* if the form validates, *false* if it contains errors. Note that if you use an ajax form validator, the actual result will be delivered asynchronously to the function *options.onAjaxFormComplete*.

    alert( $("#formID1").validationEngine('validate') );

showPrompt (promptText, type, promptPosition, showArrow)

Displays a prompt on a given element. Note that the prompt can be displayed on any element an id.

The method takes four parameters:
1. the text of the prompt itself
2. a type which defines the visual look of the prompt: ‘pass’ (green), ‘load’ (black) anything else (red)
3. an optional position: either “topLeft”, “topRight”, “bottomLeft”, “centerRight”, “bottomRight”. Defaults to *”topRight”*
4. an optional boolean which tells if the prompt should display a directional arrow

       <legend id="legendid">Email</legend>
       <a href="#" onclick="$('#legendid').validationEngine('showPrompt', 'This a custom msg', 'load')">Show prompt</a>


Closes error prompts in the current form (in case you have more than one form on the page)

    $('#formID1').validationEngine('hide')">Hide prompts


Closes **all** error prompts on the page.



Options are typically passed to the init action as a parameter.
$(“#formID1”).validationEngine({promptPosition : “centerRight”, scroll: false});


Name of the event triggering field validation, defaults to *blur*.

Tells if we should scroll the page to the first error, defaults to *true*.


Where should the prompt show ? Possible values are “topLeft”, “topRight”, “bottomLeft”, “centerRight”, “bottomRight”. Defaults to *”topRight”*.

If set to true, turns Ajax form validation logic on. defaults to *false*.
form validation takes place when the validate() action is called or when the form is submitted.

onBeforeAjaxFormValidation(form, options)
When ajaxFormValidation is turned on, function called before the asynchronous AJAX form validation call. May return false to stop the Ajax form validation

onAjaxFormComplete: function(form, status, errors, options)
When ajaxFormValidation is turned on, function is used to asynchronously process the result of the validation.

Set to true when the form shows in a scrolling div, defaults to *false*.

Selector used to pick the overflown container, defaults to *””*.


Validators are encoded in the field’s class attribute, as such


Speaks by itself, fails if the element has no value. this validator can apply to pretty much any kind of input field.

    <input value="" class="validate[required]" type="text" name="email" id="email" />
    <input class="validate[required]" type="checkbox" id="agree" name="agree"/>
    <select name="sport" id="sport" class="validate[required]" id="sport">
       <option value="">Choose a sport</option>
       <option value="option1">Tennis</option>
       <option value="option2">Football</option>
       <option value="option3">Golf</option>


Validates the element’s value to a predefined list of regular expressions.

<input value="someone@nowhere.com" class="validate[required,custom[email]]" type="text" name="email" id="email" />

Please refer to the section Custom Regex for a list of available regular expressions.


Validates a field using a third party function call. If a validation error occurs, the function must return an error message that will automatically show in the error prompt.

    function checkHELLO(field, rules, i, options){
      if (field.val() != "HELLO") {
         // this allows the use of i18 for the error msgs
         return options.allrules.validate2fields.alertText;

The following declaration will do

<input value="" class="validate[required,funcCall[checkHELLO]]" type="text" id="lastname" name="lastname" />


Delegates the validation to a server URL using an asynchronous Ajax request. The selector is used to identify a block of properties in the translation file, take the following example.

    <input value="" class="validate[required,custom[onlyLetterNumber],maxSize[20],ajax[ajaxUserCall]] text-input" type="text" name="user" id="user" />
    "ajaxUserCall": {
        "url": "ajaxValidateFieldUser",
        "extraData": "name=eric",
        "alertText": "* This user is already taken",
        "alertTextOk": "All good!",
        "alertTextLoad": "* Validating, please wait"

* url – is the remote restful service to call
* extraData – optional parameters to sent
* alertText – error prompt message is validation fails
* alertTextOk – optional prompt is validation succeeds (shows green)
* alertTextLoad – message displayed while the validation is being performed

This validator is explained in further details in the Ajax section.

Check if the current field’s value equals the value of the specified field.

Validates when the field’s value if less or equal to the given parameter.

Validates when the field’s value if more or equal to the given parameter.

Validates if the element content size (in characters) is more or equal to the given *integer*. integer <= input.value.length maxSize[integer]
Validates if the element content size (in characters) is less or equal to the given *integer*. input.value.length <= integer past[NOW or a date]

Checks if the element’s value (which is implicitly a date) is earlier than the given *date*. When “NOW” is used as a parameter, the date will be calculate in the browser. Note that this may be different that the server date. Dates use the ISO format YYYY-MM-DD

    <input value="" class="validate[required,custom[date],past[now]]" type="text" id="birthdate" name="birthdate" />
    <input value="" class="validate[required,custom[date],past[2010-01-01]]" type="text" id="appointment" name="appointment" />

future[NOW or a date]

Checks if the element’s value (which is implicitly a date) is greater than the given *date*. When “NOW” is used as a parameter, the date will be calculate in the browser. Note that this may be different that the server date. Dates use the ISO format YYYY-MM-DD

    <input value="" class="validate[required,custom[date],future[now]]" type="text" id="appointment" name="appointment" /> // a date in 2009
    <input value="" class="validate[required,custom[date],future[2009-01-01],past[2009-12-31]]" type="text" id="d1" name="d1" />


Validates when a minimum of *integer* checkboxes are selected.
The validator uses a special naming convention to identify the checkboxes part of the group.

The following example, enforces a minimum of two selected checkboxes

    <input class="validate[minCheckbox[2]]" type="checkbox" name="group1" id="maxcheck1" value="5"/>
    <input class="validate[minCheckbox[2]]" type="checkbox" name="group1" id="maxcheck2" value="3"/>
    <input class="validate[minCheckbox[2]]" type="checkbox" name="group1" id="maxcheck3" value="9"/>

Note how the input.name is identical across the fields.


Same as above but limits the maximum number of selected check boxes.


We’ve introduced the notion of selectors without giving much details about them: A selector is a string which is used as a key to match properties in the translation files.
Take the following example:

    "onlyNumber": {
        "regex": /^[0-9\ ]+$/,
        "alertText": "* Numbers only"
    "ajaxUserCall": {
        "url": "ajaxValidateFieldUser",
        "extraData": "name=eric",
        "alertText": "* This user is already taken",
        "alertTextLoad": "* Validating, please wait"
    "validate2fields": {
        "alertText": "* Please input HELLO"

onlyNumber, onlyLetter and validate2fields are all selectors. jQuery.validationEngine comes with a standard set but you are welcome to add you own to define AJAX backend services, error messages and/or new regular expressions.


Ajax validation comes in two flavors:

1. Field Ajax validations, which takes place when the user inputs a value in a field and moves away.
2. Form Ajax validation, which takes place when the form is submitted or when the validate() action is called.

Both options are optional.


The client sends the form fields and values as a GET request to the form.action url.

Client calls url?fieldId=id1&fieldValue=value1&…etc ==> Server (form.action)

Server responds with a list of arrays: [fieldid, status, errorMsg].

* fieldid is the name (id) of the field
* status is the result of the validation, true if it passes, false if it fails
* errorMsg is an error string (or a selector) to the prompt text

Client receives <== [["id1", boolean,"errorMsg"],["id2", false, "there is an error "],["id3", true, "this field is good"]] Server Note that only errors (status=false) shall be returned from the server. However you may also decide to return an entry with a status=true in which case the errorMsg will show as a green prompt.


Since the form validation is asynchronously delegated to the form action, we provide two callback methods:

**onBeforeAjaxFormValidation(form, options)** is called before the ajax form validation call, it may return false to stop the request

**onAjaxFormComplete: function(form, status, json_response_from_server, options)** is called after the ajax form validation call

Custom Regex

jQuery.validationEngine comes with a lot of predefined expressions. Regex are specified as such:

<input value="" class="validate[custom[email]]" type="text" name="email" id="email" />

Note that the selector identifies a given regular expression in the translation file, but also its associated error prompt messages and optional green prompt message.

a typical phone number with an optional country code and extension. Note that the validation is **relaxed**, please add extra validations for your specific country.

49-4312 / 777 777
+1 (305) 613-0958 x101
(305) 613 09 58 ext 101
+33 1 47 37 62 24 extension 3
(016977) 1234
04312 – 777 777
+58 295416 7216

matched a url such as http://myserver.com, https://www.crionics.com or ftp://myserver.ws

easy, an email : username@hostname.com

an ISO date, YYYY-MM-DD

floating points with an optional sign. ie. -143.22 or .77 but also +234,23

integers with an optional sign. ie. -635 +2201 738

an IP address (v4) ie.

Only numbers and spaces characters

Only letters and space characters

Only letters and numbers, no space

Using the engine in a overflown div

The big change in this method is that normally the engine will append every error boxes to the body. In this case it will append every error boxes before the input validated. This add a bit of complexity, if you want the error box to behave correctly you need to wrap the input in a div being position relative, and exactly wrapping the input width and height. The easiest way to do that is by adding float:left, like in the example provided.


What would be a good library without customization ?

Adding regular expressions

Adding new regular expressions is easy: open your translation file and add a new entry to the list

    "onlyLetter": {
        "regex": /^[a-zA-Z\ \']+$/,
        "alertText": "* Letters only"

* “onlyLetter” is a sample selector name
* “regex” is a javascript regular expression
* “alertText” is the message to display when the validation fails

You can now use the new regular expression as such

<input type="text" id="myid" name="myid" class="validation[custom[onlyLetter]]"/>

Don’t forget to contribute!

Customizing the look and feel

Edit the file *validationEngine.jquery.css* and customize the stylesheet to your likings. it’s trivial if you know CSS.

Adding more locales

You can easy add a locale by taking *jquery.validationEngine-en.js* as an example.
Feel free to share the translation 😉

Rules of thumb

* field.id are **unique** across the page
* for simplicity and consistency field.id and field.name should match (except with minCheckbox and maxCheckbox validators)
* spaces or special chars should be avoided in field.id or field.name
* use lower cases for input.type ie. *text, password, textarea, checkbox, radio*
* use the Ajax validator last ie. validate[custom[onlyLetter],length[0,100],**ajax[ajaxNameCall]**]
* use only one Ajax validator per field!
* JSON services should live on the same server (or you will get into browser security issues)
* in a perfect RESTful world, http **GET** is used to *READ* data, http **POST** is used to *WRITE* data: which translates into -> Ajax validations should use GET, the actual form post should use a POST request.


Contributions are always welcome, you may refer to the latest stable project at [GitHub](https://github.com/posabsolute/jQuery-Validation-Engine)
We use [Aptana](http://www.aptana.com/) as a Javascript editor and the Rockstart JSLint & Closure plugins http://update.rockstarapps.com/site.xml


Licensed under the MIT License


Copyright(c) 2010 Cedric Dugas
v2.0 Rewrite by Olivier Refalo

If you like and use this script, please consider buying me a beer, it’s cheap and a simple way to give back!

Version 1.7.1 Online
October 20 2010, release v1.7.1: Compatibility release for jQUery 1.4.3
July 1 2010, release v1.7: div overflown support + small fix to inline ajax validation + small code overhaul
Feb 1 2010, release v.1.6.3: bugfixs from forum + exempString rule addition, update to jQuery 1.4
November 23, release v.1.6.2: bugfix script loaded via ajax,
November 23, release v.1.6.1: Refactoring, external loadvalidation() is back working, languages are now ALL loaded externally, added setting to not unbind form on success,
October 29, release v.1.6: unbind validation when success function is called, option returnIsValid added
October 27, release v.1.5: Added debug mode, event triggerer can be specified in setting and checkbox bug with cakephp corrected
September 17, release v.1.4: More frameworks support, changes with the minCheckbox and maxCheckbox
August 25, release v. Ajax submit, prompt positioning, bug correction with multiple forms
August 13, release v.1.3: Ajax validation, prompts usable outside the plugin, minor CSS corrections
July 12, release v.1.3: Validation with ids instead of name, minor CSS corrections, optional inline validation.
June 5, release v.1.2.1: Added optional validation
June 5, release v.1.2: Less error prone reg Ex, corrected an error with multiple form on the same page
June 4, release v.1.1: added date validation and select required validation, corrected errors with group radio input
June 1, release v.1.0

Comments are closed due to the overwhelming number, please use the forums for support.


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491 thoughts on “A jQuery inline form validation, because validation is a mess

  1. Look at your documen ready, you now have to validate to your form instead of directly to you class

    success : false,
    failure : function() { callFailFunction() }

  2. Hi. Very good thing you did. But some bad things is there i think.

    I will try to redo your function in future, if you will not to do this.

    1) What if user want to exclude some bad words from sending.
    Your thing should have way to execute some custom rule in not reg ex, but something like this if(jQuery(“#field”).val()==’bad expression’) { eror =1; }

    2) i think is bad that all error shows at one time. I think it should breaks if one erorr cathed.. like in queue.

    My input have text inside this so i should check is standart value is inside or user’s text … and don’t know how to do this.

    If something will be cahnged in your script, please email me. rantie86@gmail.com

    But this very cool thing.

  3. Hello there , again 😀

    I have found some minor problem, if the input is fixed near the top side on the page when the error message appear it is partly hidden. I tried to change the callerTopPosition by
    “callerTopPosition = callerTopPosition – (callerHeight/2) -10” it fits perflecty. But when you display another message it return to his previous location or if the message is too long it appear under the input :s
    i do not know what to do :'(

  4. Hey Lifty,

    You need to change the update function too, I really never encounter a website where I had to do this, I guess I could write a condition for it in the ”near’ future

  5. how can i make radio button be a required field co’z when I use validate required, the form still submits. tnx,

  6. it validate it first, but when I submit again.. the validation does not work please post the solution tnx..

  7. Hi there. Thanks for the nice validation plugin. However, I’ve been trying to get this simple regex to work to no avail for hours now. Any help perhaps please? Here is the custom regex I’m trying to use: “regex”:”/^(?=.*\d)(?=.*[A-Z]).{8,20}$/”

  8. hi Cedric,
    firstavail, thank you for this plugin, very nice job!
    I’m trying to use the language file (jquery.validationEngine-fr.js), including it just before jquery.validationEngine.js , but it doesn’t work. Here is the error in firebug:
    “$.validationEngine.settings.allrules is undefined”.
    I’m using jquery 1.3.2
    What am I doing wrong?

  9. thx for your support, Cedric.
    I’ll be waiting for your comments. Meanwhile I keep looking.
    By the way, I’m working with Zend Framework, if that matters.

  10. Salut excuse moi j’ai un problème tout mon jquery est bien lancé et le css aussi = executé mais je n’ai pas de message d’erreur qui s’affiche 🙁

  11. @osdave, ok just check my download version, if I uncomment the french js file its work, now, if you added rules, please make sure you followed the good structure. Its kind of hard to know the problem without seeing the code

    @shinzo as tu vien mis le valide[] en permier dans ton attrivut class? c<est deja arriver à quelqu’un d’autre aussi et c’étais le probleme

  12. well, i found my problem: ZF is working LIFO (Last In First Out), that means that I need to write first what needs to be called last.
    For example, for what I’m doing right now, here is what’s in the beginning of my view:
    headLink()->appendStylesheet($this->baseUrl() . ‘/public/css/validationEngine.jquery.css’);
    $this->headScript()->appendFile($this->baseUrl() . ‘/public/js/jquery/jquery.validationEngine.js’);
    $this->headScript()->appendFile($this->baseUrl() . ‘/public/js/jquery/jquery.validationEngine-es.js’);
    $this->headScript()->appendFile($this->baseUrl() . ‘/public/js/forms/registrar.js’);

    Sorry for wasting your time, Cedric, and thanks again for your support.
    see you

  13. Hi, i think this is a cool jquery plugin. Wondering how to hide the submit button upon submission once all the fields pass the checking. I manage to hide the submit button but the form is not submitted. I add the function to hide the submit button in the success property. Any idea?

  14. j ai remarquer une chose quand je clique sur un autre form et en mettant le mauvais contenue, mon element . styl me marque top: -1643px donc j ai tout a -1643 oO

    et quand je marque le bon contenue sa me recharge ma page et pouf sa merde…

  15. @schturdark well the success fonction stop the submit , there is no call back this way, but I will be implimenting one shortly, for now you can go in the scress where teh success function is called and add you callback juste before the return false

    @Ahmet no it’s not implimented,

    @shinzo lance tu mon script dans un iframe?

  16. Non du tout

    En fait j’ai un plugin qui va transformer creer ma class suivant les element typ)text ou type=checkbox…..

    Après je crèe un formulaire = autre plugin ou je met la fonction $document.ready.

    Et là tout merdouille mon css et JS bien chargé mais bon je comprend pas pourquoi sa me fait ça. Surtout que là ouvel erreur => uncaught exception: Syntax error, unrecognized expression: .
    il reconnais pas le . oO

  17. What can I say except the thing that others already said. Brilliant plugin, brilliant work.
    And I have some tricky problem.
    This plugin works as expected in IE but not in Mozilla.
    Both browsers show baloons when some fields loose focus and here is the difference. When I click submit button IE doesnt do that if the rules arent met. However, Mozilla show ballons quickly and then submit no matter what.

    Here is the piece of my code:

    $(document).ready(function() {

    // SUCCESS AJAX CALL, replace “success: false,” by: success : function() { callSuccessFunction() },
    success : function() { Posalji_formu() },
    failure : function() { Neuspesno() }

    It is located on top of jquery.validationEngine.js file.
    In my asp page I have functions Posalji_formu and Neuspesno.

    function Posalji_formu()
    frm = document.formID;

    Do You have any hint what could be a problem?
    Thanks in advance.

  18. Try using lowercase for the first letter of you function, it seems like this function do not exist, this function should be outside of my prototype and outside of document ready,

    Also, you should use my last version, I changed lots of thing and fixed some bugs.

    but it’s not working exactly the same, in the new version you call directly the form to validate in the dom.ready and every input need an ID

  19. Will inform You on results Cedric. Thanks.
    Can You please edit my previous post about error and replace the address with something generic. Cant find Your email here, I would send You this request by email.
    Thanks again.

  20. Salut désolé de te redéranger. J’ai un soucis ^^

    Mon JS et CSS sont bien appelé mais j’ai cela : uncaught exception: Syntax error, unrecognized expression: .

    sur cette ligne

    Aurais tu une idée?

    ps: La fonction existe bien

  21. I finally found out what was the problem.
    My from is nested in table like this:

    When I put it like this:

    It works like a charm.
    Cedric, is there anything I can change in js file to be able to overcome this?
    Thanks in advance.

  22. Awesome awesome script 🙂 Ok well this newer version screwed what I was doing 🙂 Right now I have it so that there is no action in the form. If your validation works, and then I do a couple other validation routines, check image upload fields since it doesnt look like your script works with those, and then I do another test, then I assign the action attribute to the form and return true. It used to then submit the form, but now, its’ not submitting the form and Im not sure why.. any help would be appreciated.. by anyone! 🙂

  23. @Bosko: thanks for your response.. looks like it might have rejected my last post with the script content. If you go here: http://www.mppumayri.org/security-form.htm

    View the source code, the important stuff is down at the bottom. If I remove the success callback then it works, but I really would like that code to fire on success of the validation routine.

  24. Why is this line commented:


    Did You try to use $(‘#form’) instead of $(‘form’)?

  25. That’s commented out because it basically kept submitting the form, which then alerted me that the form should have submitted and then kept looping. It was ugly 🙂

    And yeah I tried #form, I made sure that $(‘form’) would work by setting the css(‘background-color’,’red’) and then also viewing the generated source code and it was definitely working. Whenever I have something besides succes: false, or success: function(){} it will fail, so there is something wrong with the success method.

  26. And what about this line:

    var formAction = ‘security-form.htm?action=submit’;

    The form is submitting to itself over and over once You fill all the fields and click submit button. Since You placed it in document.ready… this is the result.
    Did You try to submit Your data to some other page which would process form field values?

  27. It’s actually not in document.ready. And yep I even removed the formAction and set it explicitly in the form tag and still no go. Seriously the problem is in the success method, it seems to always be returning false.

  28. Do you know what is going on here?

    if($.validationEngine.submitValidation(this,settings) == false){
    if($.validationEngine.submitForm(this,settings) == true) {return false;}

    $.validationEngine.submitForm(this,settings) == true always seems to evaluate to true, which then returns false…

Comments are closed.