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Compressing a Stream

Updated on Jun 16, 2026

RadZipLibrary helps you compress a stream, for example, to send it over the internet. The library provides the CompressedStream class that compresses and decompresses streams.

This article covers the following topics:

API Overview
Compressing a Stream
Decompressing a Stream
CompressedStream Properties

API Overview

The CompressedStream class allows you to compress and decompress a stream. Initialize the class with one of the constructor overloads:

CompressedStream(Stream baseStream, StreamOperationMode mode, CompressionSettings settings)
CompressedStream(Stream baseStream, StreamOperationMode mode, CompressionSettings settings, bool useCrc32, EncryptionSettings encryptionSettings)

The parameters accepted by the constructors serve the following functions:

Stream baseStream—A reference to a stream where the compressed result is written when compressing data or the compressed stream that needs to be decompressed when decompressing data.
StreamOperationMode mode—Specifies the operation mode of the compressed stream. Use Write for compressing data and Read for decompressing.
CompressionSettings settings—The settings used for the compression. The compression settings can be of type DeflateSettings, LzmaSettings, and StoreSettings. You can read more on the topic in the Compression Settings article.
bool useCrc32—Indicates whether to use CRC32 (true) or Adler32 (false) checksum algorithm.
EncryptionSettings encryptionSettings—Specifies the encryption settings that are used. If a null value is passed, encryption is not performed. More information on the topic is available in the Protect ZipArchive article.

You can create a compressed stream by initializing a new instance of the CompressedStream class. Pass as a parameter the stream in which the compressed data is written. Set the operation mode to Write and the compression settings that the operation uses.

Example 1: Write to a compressed stream

using (CompressedStream compressedStream = new CompressedStream(outputStream, StreamOperationMode.Write, new DeflateSettings()))
			{
				//write to compressed stream
			}

If you want to compress a specific stream (inputStream), you need to copy it to the compressed stream that you created.

Example 2: Write a stream to a compressed stream

using (CompressedStream compressedStream = new CompressedStream(outputStream, StreamOperationMode.Write, new DeflateSettings()))
{
	inputStream.CopyTo(compressedStream);
	compressedStream.Flush();
}

Decompressing a Stream

Decompressing a stream follows the same pattern as compressing it. Create a new instance of the CompressedStream class and pass it the stream from which the compressed data is extracted, operation mode Read, and the compression settings that need to be used.

Example 3: Decompress a stream

using (CompressedStream compressedStream = new CompressedStream(inputStream, StreamOperationMode.Read, new DeflateSettings()))
{
	compressedStream.CopyTo(outputStream);
}

CompressedStream Properties

CompressedStream derives from the Stream class and supports all its properties. It also exposes a set of properties that provide further information about the compressed stream:

BaseStream—Property of type Stream, which obtains the stream that is compressed.
Checksum—Numeric value representing the checksum of the compressed stream.
CompressedSize—The size of the compressed stream.
Length—The uncompressed size of the stream.

Compressing a Stream

API Overview