Class CompressionMode
Specifies the compression strategy to use when reducing PDF file size.
Inheritance
Namespace: IronPdf
Assembly: IronPdf.dll
Syntax
public sealed class CompressionMode : EnumRemarks
Different compression modes balance file size, processing speed, and system resource requirements. Choose the mode that best fits your use case and system constraints.
Fields
Automatic
Automatically selects the optimal compression method based on system capabilities. This is the default and recommended option for most scenarios.
Declaration
public const CompressionMode AutomaticField Value
| Type | Description |
|---|---|
| CompressionMode |
Remarks
Behavior:
When to Use:
Recommended for most applications where you want optimal compression but need to handle varying system environments gracefully.
FastMemory
Performs compression entirely in memory without any disk I/O operations.
Declaration
public const CompressionMode FastMemoryField Value
| Type | Description |
|---|---|
| CompressionMode |
Remarks
Characteristics:
- Speed: Fastest compression method
- Security: No temporary files written to disk
- File Size: Produces larger files compared to HighQuality (no image resampling/downsampling)
- Disk I/O: Zero disk access required
When to Use:
Limitations:
Image optimization and JPEG quality settings are not applied in this mode.
HighQuality
Applies maximum compression using advanced optimization techniques. Requires temporary disk access but produces the smallest possible file size.
Declaration
public const CompressionMode HighQualityField Value
| Type | Description |
|---|---|
| CompressionMode |
Remarks
Characteristics:
- File Size: Smallest output files (maximum compression)
- Image Optimization: Applies JPEG resampling and downsampling based on quality settings
- Stream Compression: Uses maximum zlib compression on content streams
- Disk I/O: Requires writing temporary files to the system temp directory
When to Use:
System Requirements:
Requires write permissions to the system temporary directory. If disk access fails, an exception will be thrown in explicit mode, or automatic fallback to FastMemory occurs in Automatic mode.
value__
Declaration
public int value__Field Value
| Type | Description |
|---|---|
| System.Int32 |