Validation

Browser Default Validation
@ 
<form class="row g-3">
    <div class="col-md-4">
        <label for="validationDefault01" class="form-label">First name</label>
        <input type="text" class="form-control" id="validationDefault01"
            value="Mark" required>
    </div>
    <div class="col-md-4">
        <label for="validationDefault02" class="form-label">Last name</label>
        <input type="text" class="form-control" id="validationDefault02"
            value="Otto" required>
    </div>
    <div class="col-md-4">
        <label for="validationDefaultUsername" class="form-label">Username</label>
        <div class="input-group">
            <span class="input-group-text" id="inputGroupPrepend2">@</span>
            <input type="text" class="form-control" id="validationDefaultUsername"
                aria-describedby="inputGroupPrepend2" required>
        </div>
    </div>
    <div class="col-md-6">
        <label for="validationDefault03" class="form-label">City</label>
        <input type="text" class="form-control" id="validationDefault03" required>
    </div>
    <div class="col-md-3">
        <label for="validationDefault04" class="form-label">State</label>
        <select class="form-select" id="validationDefault04" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
        </select>
    </div>
    <div class="col-md-3">
        <label for="validationDefault05" class="form-label">Zip</label>
        <input type="text" class="form-control" id="validationDefault05" required>
    </div>
    <div class="col-12">
        <div class="form-check">
            <input class="form-check-input" type="checkbox" value=""
                id="invalidCheck2" required>
            <label class="form-check-label" for="invalidCheck2">
                Agree to terms and conditions
            </label>
        </div>
    </div>
    <div class="col-12">
        <button class="btn btn-primary" type="submit">Submit form</button>
    </div>
</form>
Custom Validation
Looks good!
Looks good!
@
Please choose a username.
Please provide a valid city.
Please select a valid state.
Please provide a valid zip.
You must agree before submitting. 
<form class="row g-3 needs-validation" novalidate>
    <div class="col-md-4">
        <label for="validationCustom01" class="form-label">First name</label>
        <input type="text" class="form-control" id="validationCustom01" value="Mark"
            required>
        <div class="valid-feedback">
            Looks good!
        </div>
    </div>
    <div class="col-md-4">
        <label for="validationCustom02" class="form-label">Last name</label>
        <input type="text" class="form-control" id="validationCustom02" value="Otto"
            required>
        <div class="valid-feedback">
            Looks good!
        </div>
    </div>
    <div class="col-md-4">
        <label for="validationCustomUsername" class="form-label">Username</label>
        <div class="input-group has-validation">
            <span class="input-group-text" id="inputGroupPrepend">@</span>
            <input type="text" class="form-control" id="validationCustomUsername"
                aria-describedby="inputGroupPrepend" required>
            <div class="invalid-feedback">
                Please choose a username.
            </div>
        </div>
    </div>
    <div class="col-md-6">
        <label for="validationCustom03" class="form-label">City</label>
        <input type="text" class="form-control" id="validationCustom03" required>
        <div class="invalid-feedback">
            Please provide a valid city.
        </div>
    </div>
    <div class="col-md-3">
        <label for="validationCustom04" class="form-label">State</label>
        <select class="form-select" id="validationCustom04" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
        </select>
        <div class="invalid-feedback">
            Please select a valid state.
        </div>
    </div>
    <div class="col-md-3">
        <label for="validationCustom05" class="form-label">Zip</label>
        <input type="text" class="form-control" id="validationCustom05" required>
        <div class="invalid-feedback">
            Please provide a valid zip.
        </div>
    </div>
    <div class="col-12">
        <div class="form-check">
            <input class="form-check-input" type="checkbox" value=""
                id="invalidCheck" required>
            <label class="form-check-label" for="invalidCheck">
                Agree to terms and conditions
            </label>
            <div class="invalid-feedback">
                You must agree before submitting.
            </div>
        </div>
    </div>
    <div class="col-12">
        <button class="btn btn-primary" type="submit">Submit form</button>
    </div>
</form>
Supported elements
Please enter a message in the textarea.
Example invalid feedback text
More example invalid feedback text
Example invalid select feedback
Example invalid form file feedback
<form class="was-validated">
    <div class="mb-3">
        <label for="validationTextarea" class="form-label">Textarea</label>
        <textarea class="form-control is-invalid" id="validationTextarea"
            placeholder="Required example textarea" required=""></textarea>
        <div class="invalid-feedback">
            Please enter a message in the textarea.
        </div>
    </div>

    <div class="form-check mb-3">
        <input type="checkbox" class="form-check-input" id="validationFormCheck1"
            required="">
        <label class="form-check-label" for="validationFormCheck1">Check this
            checkbox</label>
        <div class="invalid-feedback">Example invalid feedback text</div>
    </div>

    <div class="form-check">
        <input type="radio" class="form-check-input" id="validationFormCheck2"
            name="radio-stacked" required="">
        <label class="form-check-label" for="validationFormCheck2">Toggle this
            radio</label>
    </div>
    <div class="form-check mb-3">
        <input type="radio" class="form-check-input" id="validationFormCheck3"
            name="radio-stacked" required="">
        <label class="form-check-label" for="validationFormCheck3">Or toggle
            this
            other radio</label>
        <div class="invalid-feedback">More example invalid feedback text</div>
    </div>

    <div class="mb-3">
        <select class="form-select" required="" aria-label="select example">
            <option value="">Open this select menu</option>
            <option value="1">One</option>
            <option value="2">Two</option>
            <option value="3">Three</option>
        </select>
        <div class="invalid-feedback">Example invalid select feedback</div>
    </div>

    <div class="mb-3">
        <input type="file" class="form-control" aria-label="file example"
            required="">
        <div class="invalid-feedback">Example invalid form file feedback</div>
    </div>

    <div class="mb-3">
        <button class="btn btn-primary" type="submit" disabled="">Submit
            form</button>
    </div>
</form>
Server side Validation
Looks good!
Looks good!
@
Please choose a username.
Please provide a valid city.
Please select a valid state.
Please provide a valid zip.
You must agree before submitting. 
<form class="row g-3">
    <div class="col-md-4">
        <label for="validationServer01" class="form-label">First
            name</label>
        <input type="text" class="form-control is-valid"
            id="validationServer01" value="Mark" required>
        <div class="valid-feedback">
            Looks good!
        </div>
    </div>
    <div class="col-md-4">
        <label for="validationServer02" class="form-label">Last
            name</label>
        <input type="text" class="form-control is-valid"
            id="validationServer02" value="Otto" required>
        <div class="valid-feedback">
            Looks good!
        </div>
    </div>
    <div class="col-md-4">
        <label for="validationServerUsername"
            class="form-label">Username</label>
        <div class="input-group has-validation">
            <span class="input-group-text" id="inputGroupPrepend3">@</span>
            <input type="text" class="form-control is-invalid"
                id="validationServerUsername"
                aria-describedby="inputGroupPrepend3 validationServerUsernameFeedback"
                required>
            <div id="validationServerUsernameFeedback"
                class="invalid-feedback">
                Please choose a username.
            </div>
        </div>
    </div>
    <div class="col-md-6">
        <label for="validationServer03" class="form-label">City</label>
        <input type="text" class="form-control is-invalid"
            id="validationServer03"
            aria-describedby="validationServer03Feedback" required>
        <div id="validationServer03Feedback" class="invalid-feedback">
            Please provide a valid city.
        </div>
    </div>
    <div class="col-md-3">
        <label for="validationServer04" class="form-label">State</label>
        <select class="form-select is-invalid" id="validationServer04"
            aria-describedby="validationServer04Feedback" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
        </select>
        <div id="validationServer04Feedback" class="invalid-feedback">
            Please select a valid state.
        </div>
    </div>
    <div class="col-md-3">
        <label for="validationServer05" class="form-label">Zip</label>
        <input type="text" class="form-control is-invalid"
            id="validationServer05"
            aria-describedby="validationServer05Feedback" required>
        <div id="validationServer05Feedback" class="invalid-feedback">
            Please provide a valid zip.
        </div>
    </div>
    <div class="col-12">
        <div class="form-check">
            <input class="form-check-input is-invalid" type="checkbox"
                value="" id="invalidCheck3"
                aria-describedby="invalidCheck3Feedback" required>
            <label class="form-check-label" for="invalidCheck3">
                Agree to terms and conditions
            </label>
            <div id="invalidCheck3Feedback" class="invalid-feedback">
                You must agree before submitting.
            </div>
        </div>
    </div>
    <div class="col-12">
        <button class="btn btn-primary" type="submit">Submit
            form</button>
    </div>
</form>
Tooltips
Looks good!
Looks good!
@
Please choose a unique and valid username.
Please provide a valid city.
Please select a valid state.
Please provide a valid zip. 
<form class="row g-3 needs-validation" novalidate>
    <div class="col-md-4 position-relative">
        <label for="validationTooltip01" class="form-label">First
            name</label>
        <input type="text" class="form-control" id="validationTooltip01"
            value="Mark" required>
        <div class="valid-tooltip">
            Looks good!
        </div>
    </div>
    <div class="col-md-4 position-relative">
        <label for="validationTooltip02" class="form-label">Last
            name</label>
        <input type="text" class="form-control" id="validationTooltip02"
            value="Otto" required>
        <div class="valid-tooltip">
            Looks good!
        </div>
    </div>
    <div class="col-md-4 position-relative">
        <label for="validationTooltipUsername"
            class="form-label">Username</label>
        <div class="input-group has-validation">
            <span class="input-group-text"
                id="validationTooltipUsernamePrepend">@</span>
            <input type="text" class="form-control"
                id="validationTooltipUsername"
                aria-describedby="validationTooltipUsernamePrepend"
                required>
            <div class="invalid-tooltip">
                Please choose a unique and valid username.
            </div>
        </div>
    </div>
    <div class="col-md-6 position-relative">
        <label for="validationTooltip03" class="form-label">City</label>
        <input type="text" class="form-control" id="validationTooltip03"
            required>
        <div class="invalid-tooltip">
            Please provide a valid city.
        </div>
    </div>
    <div class="col-md-3 position-relative">
        <label for="validationTooltip04" class="form-label">State</label>
        <select class="form-select" id="validationTooltip04" required>
            <option selected disabled value="">Choose...</option>
            <option>...</option>
        </select>
        <div class="invalid-tooltip">
            Please select a valid state.
        </div>
    </div>
    <div class="col-md-3 position-relative">
        <label for="validationTooltip05" class="form-label">Zip</label>
        <input type="text" class="form-control" id="validationTooltip05"
            required>
        <div class="invalid-tooltip">
            Please provide a valid zip.
        </div>
    </div>
    <div class="col-12">
        <button class="btn btn-primary" type="submit">Submit
            form</button>
    </div>
</form>