PDF Compression and Optimizer API

API ID 12963

Reduce PDF file size by up to 90% while preserving visual quality, using an industry-grade Ghostscript-tiered compression engine. Choose basic, medium, or maximum compression to balance size and quality. Perfect for email attachments, web uploads, document archiving, and storage optimization. Upload a PDF and receive a downloadable compressed file with before/after size metrics. Fast, reliable, and production-ready for any document workflow.

API Documentation

Endpoints

Request

Compress a single PDF file. Attach the PDF in the file field and choose a compression level. Returns a JSON object with a downloadable URL plus original_size, compressed_size, and compression_ratio.

Endpoint ID: 25880
POST https://docs.zylalabs.com/api/12963/pdf+compression+and+optimizer+api/25880/compress+pdf
INPUT PARAMETERS

Compress PDF — Endpoint Features

Object Description
level Required Compression level: basic (best quality), medium (balanced, recommended), or maximum (smallest size).
preserve_quality Required Preserve visual quality during compression: true or false.
Request Body Required File Binary

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

level
preserve_quality
API EXAMPLE RESPONSE
JSON
{"success":true,"url":"https://pub-6db99bab215e44889f46c4b2a619f8c5.r2.dev/compressed/20260619/bb30c136-f449-4428-8aee-73a1765cde47.pdf","original_size":2526695,"compressed_size":2317882,"compression_ratio":0.9173572591864075,"space_saved_percent":8.264274081359247,"quality_score":0.95,"processing_time":"7149ms"}
Compress PDF — CODE SNIPPETS

    curl --location 'https://zylalabs.com/api/12963/pdf+compression+and+optimizer+api/25880/compress+pdf?level=basic&preserve_quality=basic' \
    --header 'Content-Type: application/json' \ 
    --form 'image=@"FILE_PATH"'

API Access Key & Authentication

After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the PDF Compression and Optimizer API simply include your bearer token in the Authorization header.

Headers
Header Description
Authorization Required Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.

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Overview

The PDF Compression and Optimizer API reduces the file size of PDF documents while maintaining readability and visual appearance. The API accepts a PDF file as input, applies compression and optimization techniques, and returns a downloadable version of the compressed document along with file size statistics.

Users can select different compression levels to balance file size reduction and document quality. Available compression modes include basic, medium, and maximum, allowing developers to choose the most suitable option for their use case. The API can also preserve visual quality during compression to help maintain the appearance of text, images, graphics, and document layouts.

The API is designed for workflows that require smaller PDF files for storage, sharing, uploading, or distribution. Compressed files can reduce storage requirements, improve transfer speeds, decrease bandwidth usage, and help meet file size restrictions imposed by email systems, document portals, and cloud platforms.

Common use cases include:

  • Reducing PDF size for email attachments

  • Optimizing files before uploading to websites

  • Preparing documents for cloud storage

  • Compressing reports, invoices, and contracts

  • Reducing storage requirements for archived documents

  • Optimizing scanned PDF files

  • Processing large volumes of PDF documents

  • Automating document management workflows

  • Preparing files for document sharing platforms

  • Reducing bandwidth usage during file transfers

Features:

  • PDF file compression and optimization

  • Multiple compression levels

  • Basic, medium, and maximum compression modes

  • Optional visual quality preservation

  • File size reduction reporting

  • Original and compressed file size metrics

  • Compression ratio information

  • Downloadable compressed PDF output

  • JSON response format

  • HTTPS-based API access

The API returns structured JSON responses containing a download URL for the compressed file, along with information such as original file size, compressed file size, compression ratio, and processing details. It can be integrated into document management systems, cloud storage platforms, workflow automation tools, business applications, web services, and other systems that process PDF documents.

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