---
title: Validate object instances
slug: cms-13/docs/validate-object-instances
docTags: 
createdAt: 2026-07-30T20:22:06.928Z
---

The validation service implements the `EPiServer.Validation.IValidationService` interface to validate object instances. Retrieve the service instance from the IoC container. The service has a single method: `IEnumerable<ValidationError> Validate(object instance);`.

:::hint{type="info"}
**Note**
In CMS 13, validators must be explicitly registered using dependency injection. Register validators with `services.AddCmsValidator<T>()` in the application startup.
:::

The service locates implementations of `EPiServer.Validation.IValidate<T>` during initialization. When a validation request comes for an object instance, the service checks which registered validators are assigned from the passed-in object, and those validators are then called to perform validation.

## IValidate\<T> interface

Create a class that implements the `EPiServer.Validation.IValidate<T>` interface, which has a single method defined as: `IEnumerable<ValidationError> Validate(T instance);`.

In CMS 13, validators must be explicitly registered using dependency injection. The validation service locates classes that implement the interface during initialization. When `EPiServer.Validation.IValidationService` validates an object instance, it calls each validator to which the object instance is assignable. Implement a validator for an interface or a base class, and that validator is called whenever an object that implements or inherits the registered type is validated.

## IContentSaveValidate\<TContent>

To validate content only during save operations, implement `IContentSaveValidate<TContent>`. This interface extends `IValidate<T>` and adds contextual information, such as which `SaveAction` was used.

:::hint{type="info"}
**Note**
Validation timing has changed in CMS 13. `ValidationAttribute` implementations are triggered during content creation scenarios such as inline block creation in `ContentArea`.
Use `IContentSaveValidate<TContent>` when validation depends on the save action or runs only during save operations.
:::

## DataAnnotationsValidator

Use the `EPiServer.Validation.DataAnnotationsValidator<T>` base class when implementing a validator that validates against attributes that inherit `System.ComponentModel.DataAnnotations.ValidationAttribute`.

## Content validation

`EPiServer.IContentRepository.Save` validates a content instance before saving to verify that required properties are set. It also validates the properties of the model class (the class inheriting `PageData` or `BlockData` or that implements `IContent`) against any attributes inheriting from `System.ComponentModel.DataAnnotations.ValidationAttribute`.

Prevent validation by using the save action `EPiServer.DataAccess.SaveAction.SkipValidation` flag during save. The following example assumes an instance of `EPiServer.IContentRepository` was retrieved from the IoC container and assigned to the variable `contentRepository`:

`contentRepository.Save(page, SaveAction.Publish | SaveAction.SkipValidation);`