Binary serialization

Serialization is the process of storing the state of an object to a storage medium. In binary serialization, the public and private fields of the object and the name of the class, including the assembly containing the class, are converted to a stream of bytes, which is then written to a data stream. When the object is subsequently deserialized, an exact clone of the original object is created.

When implementing a serialization mechanism in an object-oriented environment, you often need to make tradeoffs between ease of use and flexibility. The process can be automated to a large extent, provided you are given sufficient control over the process. For example, situations may arise where simple binary serialization is not sufficient, or there might be a specific reason to decide which fields in a class need to be serialized. The following sections examine the robust serialization mechanism provided with .NET and highlight a number of important features that allow you to customize the process to meet your needs.

Note

The state of a UTF-8 or UTF-7 encoded object is not preserved if the object is serialized and deserialized using different .NET versions.

Warning

Binary serialization can be dangerous. For more information, see BinaryFormatter security guide.

Binary serialization allows modifying private members inside an object and therefore changing the state of it. Because of this, other serialization frameworks, like System.Text.Json, that operate on the public API surface are recommended.

.NET Core

.NET Core supports binary serialization for a subset of types. You can see the list of supported types in the Serializable types section that follows. The listed types are guaranteed to be serializable between .NET Framework 4.5.1 and later versions and between .NET Core 2.0 and later versions. Other .NET implementations, such as Mono, aren't officially supported but should also work.

Serializable types

Type	Notes
Microsoft.CSharp.RuntimeBinder.RuntimeBinderException	Starting in .NET Core 2.0.4.
Microsoft.CSharp.RuntimeBinder.RuntimeBinderInternalCompilerException	Starting in .NET Core 2.0.4.
System.AccessViolationException	Starting in .NET Core 2.0.4.
System.AggregateException	Starting in .NET Core 2.0.4.
System.AppDomainUnloadedException	Starting in .NET Core 2.0.4.
System.ApplicationException	Starting in .NET Core 2.0.4.
System.ArgumentException	Starting in .NET Core 2.0.4.
System.ArgumentNullException	Starting in .NET Core 2.0.4.
System.ArgumentOutOfRangeException	Starting in .NET Core 2.0.4.
System.ArithmeticException	Starting in .NET Core 2.0.4.
System.Array
System.ArraySegment<T>
System.ArrayTypeMismatchException	Starting in .NET Core 2.0.4.
System.Attribute
System.BadImageFormatException	Starting in .NET Core 2.0.4.
System.Boolean
System.Byte
System.CannotUnloadAppDomainException	Starting in .NET Core 2.0.4.
System.Char
System.Collections.ArrayList
System.Collections.BitArray
System.Collections.Comparer
System.Collections.DictionaryEntry
System.Collections.Generic.Comparer<T>
System.Collections.Generic.Dictionary<TKey,TValue>
System.Collections.Generic.EqualityComparer<T>
System.Collections.Generic.HashSet<T>
System.Collections.Generic.KeyNotFoundException	Starting in .NET Core 2.0.4.
System.Collections.Generic.KeyValuePair<TKey,TValue>
System.Collections.Generic.LinkedList<T>
System.Collections.Generic.List<T>
System.Collections.Generic.Queue<T>
System.Collections.Generic.SortedDictionary<TKey,TValue>
System.Collections.Generic.SortedList<TKey,TValue>
System.Collections.Generic.SortedSet<T>
System.Collections.Generic.Stack<T>
System.Collections.Hashtable
System.Collections.ObjectModel.Collection<T>
System.Collections.ObjectModel.KeyedCollection<TKey,TItem>
System.Collections.ObjectModel.ObservableCollection<T>
System.Collections.ObjectModel.ReadOnlyCollection<T>
System.Collections.ObjectModel.ReadOnlyDictionary<TKey,TValue>
System.Collections.ObjectModel.ReadOnlyObservableCollection<T>
System.Collections.Queue
System.Collections.SortedList
System.Collections.Specialized.HybridDictionary
System.Collections.Specialized.ListDictionary
System.Collections.Specialized.OrderedDictionary
System.Collections.Specialized.StringCollection
System.Collections.Specialized.StringDictionary
System.Collections.Stack
System.Collections.Generic.NonRandomizedStringEqualityComparer	Starting in .NET Core 2.0.4.
System.ComponentModel.BindingList<T>
System.ComponentModel.DataAnnotations.ValidationException	Starting in .NET Core 2.0.4.
System.ComponentModel.Design.CheckoutException	Starting in .NET Core 2.0.4.
System.ComponentModel.InvalidAsynchronousStateException	Starting in .NET Core 2.0.4.
System.ComponentModel.InvalidEnumArgumentException	Starting in .NET Core 2.0.4.
System.ComponentModel.LicenseException	Starting in .NET Core 2.0.4. Serialization from .NET Framework to .NET Core is not supported.
System.ComponentModel.WarningException	Starting in .NET Core 2.0.4.
System.ComponentModel.Win32Exception	Starting in .NET Core 2.0.4.
System.Configuration.ConfigurationErrorsException	Starting in .NET Core 2.0.4.
System.Configuration.ConfigurationException	Starting in .NET Core 2.0.4.
System.Configuration.Provider.ProviderException	Starting in .NET Core 2.0.4.
System.Configuration.SettingsPropertyIsReadOnlyException	Starting in .NET Core 2.0.4.
System.Configuration.SettingsPropertyNotFoundException	Starting in .NET Core 2.0.4.
System.Configuration.SettingsPropertyWrongTypeException	Starting in .NET Core 2.0.4.
System.ContextMarshalException	Starting in .NET Core 2.0.4.
System.DBNull	Starting in .NET Core 2.0.2 and later versions.
System.Data.Common.DbException	Starting in .NET Core 2.0.4.
System.Data.ConstraintException	Starting in .NET Core 2.0.4.
System.Data.DBConcurrencyException	Starting in .NET Core 2.0.4.
System.Data.DataException	Starting in .NET Core 2.0.4.
System.Data.DataSet
System.Data.DataTable	If you set RemotingFormat to SerializationFormat.Binary, it can only be exchanged with .NET Core 2.1 and later versions.
System.Data.DeletedRowInaccessibleException	Starting in .NET Core 2.0.4.
System.Data.DuplicateNameException	Starting in .NET Core 2.0.4.
System.Data.EvaluateException	Starting in .NET Core 2.0.4.
System.Data.InRowChangingEventException	Starting in .NET Core 2.0.4.
System.Data.InvalidConstraintException	Starting in .NET Core 2.0.4.
System.Data.InvalidExpressionException	Starting in .NET Core 2.0.4.
System.Data.MissingPrimaryKeyException	Starting in .NET Core 2.0.4.
System.Data.NoNullAllowedException	Starting in .NET Core 2.0.4.
System.Data.Odbc.OdbcException	Starting in .NET Core 2.0.4.
System.Data.OperationAbortedException	Starting in .NET Core 2.0.4.
System.Data.PropertyCollection
System.Data.ReadOnlyException	Starting in .NET Core 2.0.4.
System.Data.RowNotInTableException	Starting in .NET Core 2.0.4.
System.Data.SqlClient.SqlException	Starting in .NET Core 2.0.4. Serialization from .NET Framework to .NET Core is not supported
System.Data.SqlTypes.SqlAlreadyFilledException	Starting in .NET Core 2.0.4.
System.Data.SqlTypes.SqlBoolean
System.Data.SqlTypes.SqlByte
System.Data.SqlTypes.SqlDateTime
System.Data.SqlTypes.SqlDouble
System.Data.SqlTypes.SqlGuid
System.Data.SqlTypes.SqlInt16
System.Data.SqlTypes.SqlInt32
System.Data.SqlTypes.SqlInt64
System.Data.SqlTypes.SqlNotFilledException	Starting in .NET Core 2.0.4.
System.Data.SqlTypes.SqlNullValueException	Starting in .NET Core 2.0.4.
System.Data.SqlTypes.SqlString
System.Data.SqlTypes.SqlTruncateException	Starting in .NET Core 2.0.4.
System.Data.SqlTypes.SqlTypeException	Starting in .NET Core 2.0.4.
System.Data.StrongTypingException	Starting in .NET Core 2.0.4.
System.Data.SyntaxErrorException	Starting in .NET Core 2.0.4.
System.Data.VersionNotFoundException	Starting in .NET Core 2.0.4.
System.DataMisalignedException	Starting in .NET Core 2.0.4.
System.DateTime
System.DateTimeOffset
System.Decimal
System.Diagnostics.Contracts.ContractException	Starting in .NET Core 2.0.4.
System.Diagnostics.Tracing.EventSourceException	Starting in .NET Core 2.0.4.
System.IO.DirectoryNotFoundException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.MultipleMatchesException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.NoMatchingPrincipalException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.PasswordException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.PrincipalException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.PrincipalExistsException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.PrincipalOperationException	Starting in .NET Core 2.0.4.
System.DirectoryServices.AccountManagement.PrincipalServerDownException	Starting in .NET Core 2.0.4.
System.DirectoryServices.ActiveDirectory.ActiveDirectoryObjectExistsException	Starting in .NET Core 2.0.4.
System.DirectoryServices.ActiveDirectory.ActiveDirectoryObjectNotFoundException	Starting in .NET Core 2.0.4.
System.DirectoryServices.ActiveDirectory.ActiveDirectoryOperationException	Starting in .NET Core 2.0.4.
System.DirectoryServices.ActiveDirectory.ActiveDirectoryServerDownException	Starting in .NET Core 2.0.4.
System.DirectoryServices.ActiveDirectory.ForestTrustCollisionException	Starting in .NET Core 2.0.4.
System.DirectoryServices.ActiveDirectory.SyncFromAllServersOperationException	Starting in .NET Core 2.0.4.
System.DirectoryServices.DirectoryServicesCOMException	Starting in .NET Core 2.0.4.
System.DirectoryServices.Protocols.BerConversionException	Starting in .NET Core 2.0.4.
System.DirectoryServices.Protocols.DirectoryException	Starting in .NET Core 2.0.4.
System.DirectoryServices.Protocols.DirectoryOperationException	Starting in .NET Core 2.0.4.
System.DirectoryServices.Protocols.LdapException	Starting in .NET Core 2.0.4.
System.DirectoryServices.Protocols.TlsOperationException	Starting in .NET Core 2.0.4.
System.DivideByZeroException	Starting in .NET Core 2.0.4.
System.DllNotFoundException	Starting in .NET Core 2.0.4.
System.Double
System.Drawing.Bitmap	Starting in .NET Core 3.0
System.Drawing.Color
System.Drawing.Icon	Starting in .NET Core 3.0
System.Drawing.Image	Starting in .NET Core 3.0
System.Drawing.Imaging.Metafile	Starting in .NET Core 3.0
System.Drawing.Point
System.Drawing.PointF
System.Drawing.Rectangle
System.Drawing.RectangleF
System.Drawing.Size
System.Drawing.SizeF
System.DuplicateWaitObjectException	Starting in .NET Core 2.0.4.
System.EntryPointNotFoundException	Starting in .NET Core 2.0.4.
System.Enum
System.EventArgs	Starting in .NET Core 2.0.6.
System.Exception
System.ExecutionEngineException	Starting in .NET Core 2.0.4.
System.FieldAccessException	Starting in .NET Core 2.0.4.
System.FormatException	Starting in .NET Core 2.0.4.
System.Globalization.CompareInfo
System.Globalization.CultureNotFoundException	Starting in .NET Core 2.0.4.
System.Globalization.SortVersion
System.Guid
System.IO.Compression.ZLibException	Starting in .NET Core 2.0.4.
System.IO.DriveNotFoundException	Starting in .NET Core 2.0.4.
System.IO.EndOfStreamException	Starting in .NET Core 2.0.4.
System.IO.FileFormatException	Starting in .NET Core 2.0.4.
System.IO.FileLoadException	Starting in .NET Core 2.0.4.
System.IO.FileNotFoundException	Starting in .NET Core 2.0.4.
System.IO.IOException	Starting in .NET Core 2.0.4.
System.IO.InternalBufferOverflowException	Starting in .NET Core 2.0.4.
System.IO.InvalidDataException	Starting in .NET Core 2.0.4.
System.IO.IsolatedStorage.IsolatedStorageException	Starting in .NET Core 2.0.4.
System.IO.PathTooLongException	Starting in .NET Core 2.0.4.
System.IndexOutOfRangeException	Starting in .NET Core 2.0.4.
System.InsufficientExecutionStackException	Starting in .NET Core 2.0.4.
System.InsufficientMemoryException	Starting in .NET Core 2.0.4.
System.Int16
System.Int32
System.Int64
System.IntPtr
System.InvalidCastException	Starting in .NET Core 2.0.4.
System.InvalidOperationException	Starting in .NET Core 2.0.4.
System.InvalidProgramException	Starting in .NET Core 2.0.4.
System.InvalidTimeZoneException	Starting in .NET Core 2.0.4.
System.MemberAccessException	Starting in .NET Core 2.0.4.
System.MethodAccessException	Starting in .NET Core 2.0.4.
System.MissingFieldException	Starting in .NET Core 2.0.4.
System.MissingMemberException	Starting in .NET Core 2.0.4.
System.MissingMethodException	Starting in .NET Core 2.0.4.
System.MulticastNotSupportedException	Starting in .NET Core 2.0.4.
System.Net.Cookie
System.Net.CookieCollection
System.Net.CookieContainer
System.Net.CookieException	Starting in .NET Core 2.0.4.
System.Net.HttpListenerException	Starting in .NET Core 2.0.4.
System.Net.Mail.SmtpException	Starting in .NET Core 2.0.4.
System.Net.Mail.SmtpFailedRecipientException	Starting in .NET Core 2.0.4.
System.Net.Mail.SmtpFailedRecipientsException	Starting in .NET Core 2.0.4.
System.Net.NetworkInformation.NetworkInformationException	Starting in .NET Core 2.0.4.
System.Net.NetworkInformation.PingException	Starting in .NET Core 2.0.4.
System.Net.ProtocolViolationException	Starting in .NET Core 2.0.4.
System.Net.Sockets.SocketException	Starting in .NET Core 2.0.4.
System.Net.WebException	Starting in .NET Core 2.0.4.
System.Net.WebSockets.WebSocketException	Starting in .NET Core 2.0.4.
System.NotFiniteNumberException	Starting in .NET Core 2.0.4.
System.NotImplementedException	Starting in .NET Core 2.0.4.
System.NotSupportedException	Starting in .NET Core 2.0.4.
System.NullReferenceException	Starting in .NET Core 2.0.4.
System.Nullable<T>
System.Numerics.BigInteger
System.Numerics.Complex
System.Object
System.ObjectDisposedException	Starting in .NET Core 2.0.4.
System.OperationCanceledException	Starting in .NET Core 2.0.4.
System.OutOfMemoryException	Starting in .NET Core 2.0.4.
System.OverflowException	Starting in .NET Core 2.0.4.
System.PlatformNotSupportedException	Starting in .NET Core 2.0.4.
System.RankException	Starting in .NET Core 2.0.4.
System.Reflection.AmbiguousMatchException	Starting in .NET Core 2.0.4.
System.Reflection.CustomAttributeFormatException	Starting in .NET Core 2.0.4.
System.Reflection.InvalidFilterCriteriaException	Starting in .NET Core 2.0.4.
System.Reflection.ReflectionTypeLoadException	Starting in .NET Core 2.0.4. Serialization from .NET Framework to .NET Core is not supported.
System.Reflection.TargetException	Starting in .NET Core 2.0.4.
System.Reflection.TargetInvocationException	Starting in .NET Core 2.0.4.
System.Reflection.TargetParameterCountException	Starting in .NET Core 2.0.4.
System.Resources.MissingManifestResourceException	Starting in .NET Core 2.0.4.
System.Resources.MissingSatelliteAssemblyException	Starting in .NET Core 2.0.4.
System.Runtime.CompilerServices.RuntimeWrappedException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.COMException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.ExternalException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.InvalidComObjectException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.InvalidOleVariantTypeException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.MarshalDirectiveException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.SEHException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.SafeArrayRankMismatchException	Starting in .NET Core 2.0.4.
System.Runtime.InteropServices.SafeArrayTypeMismatchException	Starting in .NET Core 2.0.4.
System.Runtime.Serialization.InvalidDataContractException	Starting in .NET Core 2.0.4.
System.Runtime.Serialization.SerializationException	Starting in .NET Core 2.0.4.
System.SByte
System.Security.AccessControl.PrivilegeNotHeldException	Starting in .NET Core 2.0.4.
System.Security.Authentication.AuthenticationException	Starting in .NET Core 2.0.4.
System.Security.Authentication.InvalidCredentialException	Starting in .NET Core 2.0.4.
System.Security.Cryptography.CryptographicException	Starting in .NET Core 2.0.4.
System.Security.Cryptography.CryptographicUnexpectedOperationException	Starting in .NET Core 2.0.4.
System.Security.Cryptography.Xml.CryptoSignedXmlRecursionException	Starting in .NET Core 2.0.4.
System.Security.HostProtectionException	Starting in .NET Core 2.0.4.
System.Security.Policy.PolicyException	Starting in .NET Core 2.0.4.
System.Security.Principal.IdentityNotMappedException	Starting in .NET Core 2.0.4.
System.Security.SecurityException	Starting in .NET Core 2.0.4. Limited serialization data.
System.Security.VerificationException	Starting in .NET Core 2.0.4.
System.Security.XmlSyntaxException	Starting in .NET Core 2.0.4.
System.ServiceProcess.TimeoutException	Starting in .NET Core 2.0.4.
System.Single
System.StackOverflowException	Starting in .NET Core 2.0.4.
System.String
System.StringComparer
System.SystemException	Starting in .NET Core 2.0.4.
System.Text.DecoderFallbackException	Starting in .NET Core 2.0.4.
System.Text.EncoderFallbackException	Starting in .NET Core 2.0.4.
System.Text.RegularExpressions.RegexMatchTimeoutException	Starting in .NET Core 2.0.4.
System.Text.StringBuilder
System.Threading.AbandonedMutexException	Starting in .NET Core 2.0.4.
System.Threading.BarrierPostPhaseException	Starting in .NET Core 2.0.4.
System.Threading.LockRecursionException	Starting in .NET Core 2.0.4.
System.Threading.SemaphoreFullException	Starting in .NET Core 2.0.4.
System.Threading.SynchronizationLockException	Starting in .NET Core 2.0.4.
System.Threading.Tasks.TaskCanceledException	Starting in .NET Core 2.0.4.
System.Threading.Tasks.TaskSchedulerException	Starting in .NET Core 2.0.4.
System.Threading.ThreadAbortException	Starting in .NET Core 2.0.4.
System.Threading.ThreadInterruptedException	Starting in .NET Core 2.0.4.
System.Threading.ThreadStartException	Starting in .NET Core 2.0.4.
System.Threading.ThreadStateException	Starting in .NET Core 2.0.4.
System.Threading.WaitHandleCannotBeOpenedException	Starting in .NET Core 2.0.4.
System.TimeSpan
System.TimeZoneInfo.AdjustmentRule
System.TimeZoneInfo
System.TimeZoneNotFoundException	Starting in .NET Core 2.0.4.
System.TimeoutException	Starting in .NET Core 2.0.4.
System.Transactions.TransactionAbortedException	Starting in .NET Core 2.0.4.
System.Transactions.TransactionException	Starting in .NET Core 2.0.4.
System.Transactions.TransactionInDoubtException	Starting in .NET Core 2.0.4.
System.Transactions.TransactionManagerCommunicationException	Starting in .NET Core 2.0.4.
System.Transactions.TransactionPromotionException	Starting in .NET Core 2.0.4.
System.Tuple
System.TypeAccessException	Starting in .NET Core 2.0.4.
System.TypeInitializationException	Starting in .NET Core 2.0.4.
System.TypeLoadException	Starting in .NET Core 2.0.4.
System.TypeUnloadedException	Starting in .NET Core 2.0.4.
System.UInt16
System.UInt32
System.UInt64
System.UIntPtr
System.UnauthorizedAccessException	Starting in .NET Core 2.0.4.
System.Uri
System.UriFormatException	Starting in .NET Core 2.0.4.
System.ValueTuple	Not serializable in .NET Framework 4.7 and earlier versions.
System.ValueType
System.Version
System.WeakReference<T>
System.WeakReference
System.Xml.Schema.XmlSchemaException	Starting in .NET Core 2.0.4.
System.Xml.Schema.XmlSchemaInferenceException	Starting in .NET Core 2.0.4.
System.Xml.Schema.XmlSchemaValidationException	Starting in .NET Core 2.0.4.
System.Xml.XPath.XPathException	Starting in .NET Core 2.0.4.
System.Xml.XmlException	Starting in .NET Core 2.0.4.
System.Xml.Xsl.XsltCompileException	Starting in .NET Core 2.0.4.
System.Xml.Xsl.XsltException	Starting in .NET Core 2.0.4.

See also

• System.Runtime.Serialization
  Contains classes that can be used for serializing and deserializing objects.

• XML and SOAP Serialization
  Describes the XML serialization mechanism that is included with the common language runtime.