Resize PDF API & SDK

Programmatic Document Dimension Control

Powerful Document Dimension Control at Your Fingertips

The Resize PDF API provides developers with programmatic control over PDF document dimensions, enabling precise adjustments to meet specific output requirements. This API is built for development teams who need to integrate robust PDF resizing capabilities into their applications, workflows, or document management systems.

Whether you're building document processing pipelines, creating publishing platforms, or developing enterprise document management solutions, our API offers the technical foundation to implement custom PDF resizing with minimal code. The API maintains document clarity and formatting integrity while allowing granular control over dimensions, margins, and page selection.

Unlike general-purpose PDF libraries that require extensive configuration or cloud-based solutions with limited customization options, our Resize PDF API delivers a focused, high-performance solution for document dimension manipulation with predictable results across all document types.

Technical Features and Capabilities

Precision Dimension Control

Set exact document dimensions with decimal-point precision from 0.1 to 200 inches for both width and height. The API defaults to standard A4 dimensions (8.3 × 11.7 inches) but accepts custom values to accommodate any output requirement. This flexibility allows for resizing documents to match specific printer requirements, digital display formats, or standardized document templates.

width: number($float)
The width in inches. Value range: 0.1-200 inches. Default: 8.3 inches

height: number($float)
The height in inches. Value range: 0.1-200 inches. Default: 11.7 inches

Selective
Page Processing

Process specific pages within multi-page documents by defining exact page ranges and individual pages. The API supports comma-separated page numbers and hyphenated ranges (e.g., "1,3,5-7"), giving you precise control over which pages to resize. This targeted approach is particularly valuable when working with documents where only certain sections require dimension adjustments.

pages: string
Format examples:"1,3,5"or"1-3,7"or"1,3-5,7-9"

Pages appear in ascending order in the output regardless of input order

Password-Protected Document Support

Seamlessly process secured PDFs by providing the document password as a parameter. This feature eliminates workflow interruptions when handling protected documents and maintains security protocols throughout the processing pipeline. The API handles authentication transparently, allowing your application to maintain continuous document processing.

password: string
The password to open the protected PDF file

Asynchronous Processing Architecture

The API implements an asynchronous processing model, returning an operation ID immediately while processing continues in the background. This architecture prevents blocking operations and enables efficient handling of larger documents. Monitor operation status through the /operation/v1/{operationId}/status endpoint to determine when processing is complete.

{
"id":"3fa85f64-5717-4562-b3fc-2c963f66afa6"
}
        

Custom Margin Management

Define non-uniform margins to create documents with specific layout requirements. Set different measurements for top, bottom, left, and right margins independently, accommodating specialized document formats or printing requirements. This granular control enables precise document formatting that meets exact specifications for professional output.

For example, you can create documents with:
Extra binding space on the left margin
Balanced margins for centered content
Minimal margins for maximum content area
Custom header/footer space with expanded top/bottom margins

The batch processing engine maintains consistent performance regardless of the number of input files, with predictable memory usage that scales linearly with document complexity.

Document Integrity Preservation

The API maintains visual fidelity during resizing operations, preserving text clarity, image quality, and vector graphics precision. This technical approach ensures that resized documents remain professional and readable regardless of the dimension changes applied. Font rendering, image resolution, and element positioning are all carefully preserved during the transformation process.

Implementation Guide

RESTful API Integration

The Resize PDF API follows RESTful principles with a straightforward endpoint structure:

POST/resize-pdf/v1

The API accepts multipart/form-data with the following parameters:

file: The PDF file to resize (binary, max 10MB)

password: Optional password for protected documents

pages: Optional page selection (e.g., "1,3,5-7")

width: Optional width in inches (0.1-200, default 8.3)

height: Optional height in inches (0.1-200, default 11.7)

Response codes provide clear status information:

202: Success, returns operation ID

400: Invalid request parameters

401: Authentication failure

413: File exceeds size limit

SDK Implementation

For developers who prefer direct library integration over API calls, our SDK provides the same functionality with native language bindings. The SDK offers additional benefits including:

  • Reduced network overhead for high-volume processing

  • Progress monitoring for long-running operations

  • Simplified error handling and retry logic

  • Consistent cross-platform behavior

  • Automatic parameter validation

How the Resize PDF Process Works

1. Document Upload

Select a PDF file to resize by uploading from your local system or cloud storage service (Google Drive, Dropbox, etc.). The API accepts direct file uploads or file references, supporting documents up to 10MB in size. For programmatic integration, implement a standard multipart form upload or provide a file stream directly to the API endpoint.

2. Configure Resize Parameters

Specify your desired document dimensions and processing options:
Set exact width and height measurements (in inches)
Define custom margins for precise layout control
Specify which pages to process (all pages by default)
Provide password for secured documents if needed

3. Process and Retrieve

The API processes your document according to the specified parameters and makes the resized PDF available for download. For asynchronous operations, monitor the operation status endpoint until processing is complete, then retrieve the finished document. All processed files are automatically removed after download to maintain document security.

Did You Know?

Margins aren't a modern invention. Even our ancestors used margins to help them format their text! Margins were first used in ancient Egyptian papyrus scrolls. Because scrolls were unrolled horizontally, columns of text were separated by margins to indicate to the reader when to move down to the next line.

Technical Advantages

SDK vs. SaaS Comparison

Capability
Processing Location
Resize PDF SDK
On-premises or private cloud
SaaS Alternatives
Vendor servers
Capability
Document Privacy
Resize PDF SDK
Files never leave your infrastructure
SaaS Alternatives
Documents transmitted to third-party
Capability
Integration Depth
Resize PDF SDK
Direct library calls
SaaS Alternatives
API requests over HTTP
Capability
Offline Operation
Resize PDF SDK
Fully functional without internet
SaaS Alternatives
Requires constant connectivity
Capability
Customization
Resize PDF SDK
Full access to processing pipeline
SaaS Alternatives
Limited to provided API parameters
Capability
Performance
Resize PDF SDK
No network latency for file transfer
SaaS Alternatives
Dependent on internet connection
Capability
Volume Processing
Resize PDF SDK
Limited only by local resources
SaaS Alternatives
Often subject to rate limiting

Deployment Flexibility

The Resize PDF solution supports multiple deployment models to fit your infrastructure requirements:

  • Container-based deployment for microservices architectures
  • Server integration for traditional application servers
  • Serverless function implementation for cloud platforms
  • Desktop application embedding for client-side processing
  • CI/CD pipeline integration for automated document workflows

This flexibility ensures that you can implement PDF resizing capabilities in the environment that best matches your technical stack and security requirements.

Complementary PDF Capabilities

PDF Compression

Combine resizing with compression to further reduce file size while maintaining document quality. Our compression tools intelligently reduce PDF file size by optimizing internal structures, removing redundancies, and applying content-aware compression algorithms. This combination is particularly effective for preparing documents for web distribution or email transmission.

Format Conversion

Transform documents between PDF and other formats as part of your document workflow. Our conversion tools support bidirectional transformation between PDF and Microsoft Office formats (Word, Excel, PowerPoint) as well as common image formats. This capability enables comprehensive document processing pipelines that can accept multiple input formats and produce standardized output.

Frequently Asked Questions

How do I change my PDF dimensions?

After uploading your PDF through the API, specify the new dimensions using the width and height parameters (in inches). The API will resize the document according to these specifications while maintaining content quality and formatting.

How can I reduce the size of a PDF while maintaining high quality?

The Resize PDF API adapts your PDF dimensions while preserving the quality of images, fonts, and other content. For file size reduction, combine dimension adjustment with our PDF Compress API, which reduces the actual file size through content-aware compression techniques.

How secure is it to resize PDF files through the API?

We prioritize document security throughout the processing pipeline. All files are processed in isolated environments, transmitted using secure protocols, and automatically removed after processing. For maximum security, consider the SDK deployment option, which keeps all documents within your infrastructure.

Size and daily usage limitations may apply based on your service tier.