Form Validation - Filament

Introduction

Filament provides both frontend and backend validation for forms. Unlike traditional Laravel validation that uses string-based rules like 'required|max:255', Filament uses chainable methods that provide IDE autocompletion and immediate feedback to users.

Adding validation rules

Validation rules are added to fields using dedicated methods:

use Filament\Forms\Components\TextInput;

TextInput::make('name')
    ->required()
    ->maxLength(255)
    ->minLength(3)

Available validation rules

Required

Make a field required:

TextInput::make('email')
    ->required()

By default, required fields show an asterisk. You can hide it:

TextInput::make('name')
    ->required()
    ->markAsRequired(false)

Conditional required

TextInput::make('tax_id')
    ->requiredIf('is_company', true)

String length

TextInput::make('username')
    ->minLength(3)
    ->maxLength(20)
    ->length(10) // Exactly 10 characters

Numeric values

TextInput::make('age')
    ->numeric()
    ->minValue(18)
    ->maxValue(120)

String formats

TextInput::make('email')
    ->email()
    ->required()

IP addresses

TextInput::make('ip_address')
    ->ip() // IPv4 or IPv6

TextInput::make('ip_address')
    ->ipv4()

TextInput::make('ip_address')
    ->ipv6()

MAC address

TextInput::make('mac_address')
    ->macAddress()

Hex color

TextInput::make('color')
    ->hexColor()

JSON

TextInput::make('settings')
    ->json()

Date validation

DatePicker::make('end_date')
    ->after('start_date')

DatePicker::make('event_date')
    ->after('tomorrow')

String patterns

TextInput::make('code')
    ->startsWith(['PRD-', 'DEV-'])

Regex patterns

TextInput::make('phone')
    ->regex('/^[0-9]{10}$/')

TextInput::make('username')
    ->notRegex('/[^a-z0-9_]/')

Field comparison

TextInput::make('password_confirmation')
    ->same('password')

List validation

Select::make('status')
    ->in(['draft', 'published', 'archived'])

Select::make('status')
    ->notIn(['deleted', 'banned'])

Database validation

TextInput::make('email')
    ->unique()
    ->required()

// Specify table and column
TextInput::make('slug')
    ->unique(table: 'posts', column: 'slug')

// Ignore current record when editing
TextInput::make('email')
    ->unique(ignoreRecord: true)

Enum validation

use App\Enums\Status;

Select::make('status')
    ->enum(Status::class)

Prohibited fields

// Field must be empty
Hidden::make('honeypot')
    ->prohibited()

// Prohibited if another field has specific value
TextInput::make('other_reason')
    ->prohibitedIf('reason', 'none')

// Prohibited unless
TextInput::make('custom_domain')
    ->prohibitedUnless('plan', 'enterprise')

// Prohibits other fields
Toggle::make('use_default_settings')
    ->prohibits(['custom_setting_1', 'custom_setting_2'])

Custom validation rules

You can add custom Laravel validation rules:

Using rule classes

use App\Rules\ValidDomain;

TextInput::make('domain')
    ->rules([new ValidDomain()])

Using closure rules

use Closure;

TextInput::make('username')
    ->rules([
        fn (): Closure => function (string $attribute, $value, Closure $fail) {
            if (strtolower($value) === 'admin') {
                $fail('The username "admin" is reserved.');
            }
        },
    ])

Accessing other field values

use Filament\Schemas\Components\Utilities\Get;
use Closure;

TextInput::make('discount_amount')
    ->rules([
        fn (Get $get): Closure => function (string $attribute, $value, Closure $fail) use ($get) {
            $price = $get('price');
            if ($value > $price) {
                $fail('The discount cannot exceed the price.');
            }
        },
    ])

Using Laravel validation rules

You can use any Laravel validation rule:

TextInput::make('password')
    ->rules(['required', 'min:8', 'regex:/[a-z]/', 'regex:/[A-Z]/', 'regex:/[0-9]/'])

Customizing validation messages

Custom error messages

TextInput::make('email')
    ->email()
    ->unique()
    ->validationMessages([
        'unique' => 'This email is already registered.',
        'email' => 'Please enter a valid email address.',
    ])

Custom validation attributes

Change the field name used in error messages:

TextInput::make('dob')
    ->required()
    ->validationAttribute('date of birth')
// Error: "The date of birth field is required."

Allowing HTML in messages

TextInput::make('password')
    ->required()
    ->rules([new ComplexPasswordRule()])
    ->allowHtmlValidationMessages()

Real-time validation patterns

Validate on blur

TextInput::make('email')
    ->email()
    ->unique()
    ->live(onBlur: true)

Validate while typing (debounced)

TextInput::make('username')
    ->unique()
    ->live(debounce: 500)

Validate immediately

Select::make('country')
    ->options([...])
    ->live()
    ->afterStateUpdated(function (Select $component) {
        $component->validate();
    })

Common validation patterns

Password confirmation

TextInput::make('password')
    ->password()
    ->required()
    ->minLength(8)
    ->same('password_confirmation')

TextInput::make('password_confirmation')
    ->password()
    ->required()
    ->saved(false)

Email with confirmation

TextInput::make('email')
    ->email()
    ->required()
    ->confirmed()

TextInput::make('email_confirmation')
    ->email()
    ->required()
    ->saved(false)

Conditional validation based on other fields

use Filament\Schemas\Components\Utilities\Get;

TextInput::make('company_name')
    ->required(fn (Get $get) => $get('is_company') === true)

TextInput::make('tax_id')
    ->required(fn (Get $get) => $get('is_company') === true)
    ->length(9)

Date range validation

DatePicker::make('start_date')
    ->required()
    ->maxDate(now()->addYear())

DatePicker::make('end_date')
    ->required()
    ->after('start_date')
    ->maxDate(now()->addYears(2))

File upload validation

FileUpload::make('avatar')
    ->image()
    ->maxSize(1024) // 1MB
    ->imageResizeMode('cover')
    ->imageCropAspectRatio('1:1')
    ->acceptedFileTypes(['image/png', 'image/jpeg'])

FileUpload::make('documents')
    ->multiple()
    ->maxFiles(5)
    ->acceptedFileTypes(['application/pdf', 'application/msword'])
    ->maxSize(5120) // 5MB per file

Price validation

TextInput::make('price')
    ->numeric()
    ->required()
    ->minValue(0.01)
    ->step(0.01)
    ->prefix('$')

TextInput::make('discount_price')
    ->numeric()
    ->lt('price')
    ->minValue(0)

URL validation

TextInput::make('website')
    ->url()
    ->prefix('https://')
    ->suffixIcon('heroicon-o-globe-alt')

Disabling validation

Prevent validation on fields that aren’t saved:

TextInput::make('calculated_field')
    ->saved(false)
    ->validatedWhenNotDehydrated(false)

Best practices

Frontend vs backend validation

Use Filament’s validation methods for immediate user feedback
Always validate on the backend as well for security
Use live() strategically to balance UX and performance

Error messages

Provide clear, actionable error messages
Customize messages for better UX
Be specific about what’s wrong and how to fix it

Performance

Use live(onBlur: true) for text inputs to avoid excessive requests
Use live(debounce: 500) for real-time validation with typing
Avoid validating on every keystroke unless necessary

Accessibility

Required fields should be clearly marked
Error messages should be descriptive
Use validationAttribute() for user-friendly field names

Next steps

Advanced Features - Learn about reactive and dependent fields
Fields - Explore all available form fields

Getting Started

Panel Builder

Core Concepts

Building Blocks

Advanced

​Introduction

​Adding validation rules

​Available validation rules

​Required

​Conditional required

​String length

​Numeric values

​String formats

​IP addresses

​MAC address

​Hex color

​JSON

​Date validation

​String patterns

​Regex patterns

​Field comparison

​List validation

​Database validation

​Enum validation

​Prohibited fields

​Custom validation rules

​Using rule classes

​Using closure rules

​Accessing other field values

​Using Laravel validation rules

​Customizing validation messages

​Custom error messages

​Custom validation attributes

​Allowing HTML in messages

​Real-time validation patterns

​Validate on blur

​Validate while typing (debounced)

​Validate immediately

​Common validation patterns

​Password confirmation

​Email with confirmation

​Conditional validation based on other fields

​Date range validation

​File upload validation

​Price validation

​URL validation

​Disabling validation

​Best practices

​Frontend vs backend validation

​Error messages

​Performance

​Accessibility

​Next steps

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