Compress PDF API

Available

Optimize PDF documents by stripping unused XML metadata, flattening object streams, and slicing unused page ranges.

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Need general upload and polling mechanics?

See File Conversion for multipart upload (POST /api/uploads), polling intervals, and download token authentication.

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Browser Execution vs. REST API

In the web application interface (/optimize/compress-pdf), PDF compression executes entirely inside the browser using pdf-lib without server upload. When automating via the REST API, call POST /api/conversions with jobIntent: "transform" and metadata: "remove" to optimize the PDF server-side.

Optimization Mechanisms

• Metadata Stripping: PDF documents often accumulate several megabytes of redundant XML metadata packets, Adobe Photoshop editing histories, and embedded thumbnail images. The metadata: "remove" option strips these streams while preserving vector curves and text streams.

• Page Slicing: Large multi-page reports can be compressed by extracting only the required pages using the pageRange parameter.

Request Specification

POST /api/conversions HTTP/1.1

Host: api.orbconvert.com

Authorization: Bearer <API_KEY>

Content-Type: application/json

{
  "fileId": "<FILE_ID>",
  "toFormat": "pdf",
  "jobIntent": "transform",
  "options": {
    "metadata": "remove"
  }
}

Parameter	Type	Required	Description
fileId	string	Yes	The storage key returned by POST /api/uploads for the source PDF.
toFormat	string	Yes	Must be 'pdf'. Accepted: "pdf"
jobIntent	string	Yes	Must be set to 'transform' to allow same-format PDF optimization. Accepted: "transform"
options.metadata	string	No	Strips internal author, title, and creation timestamp metadata. Accepted: "remove" \| "keep"
options.pageRange	string	No	Extracts and optimizes only specified pages (e.g. '1-5' or 'all'). Accepted: Expression like "1-5" or "all"

Errors Specific to PDF Compression

HTTP	Error Code	Cause & Resolution
400	SAME_FORMAT_NOOP	Missing jobIntent: 'transform' in request body.
400	CORRUPT_FILE	Uploaded PDF file is corrupted or cannot be parsed by pdf-lib.
413	FILE_TOO_LARGE	PDF document exceeds max upload size limit for plan.

Code Examples

# Optimize and compress a PDF document by stripping metadata
curl -X POST "https://api.orbconvert.com/api/conversions" \
  -H "Authorization: Bearer <API_KEY>" \
  -H "Content-Type: application/json" \
  -d '{
    "fileId": "<FILE_ID>",
    "toFormat": "pdf",
    "jobIntent": "transform",
    "options": {
      "metadata": "remove"
    }
  }'

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Optimization Mechanisms

• Page Slicing: Large multi-page reports can be compressed by extracting only the required pages using the pageRange parameter.

Request Specification

POST /api/conversions HTTP/1.1

Host: api.orbconvert.com

Authorization: Bearer <API_KEY>

Content-Type: application/json

{
  "fileId": "<FILE_ID>",
  "toFormat": "pdf",
  "jobIntent": "transform",
  "options": {
    "metadata": "remove"
  }
}

Parameter	Type	Required	Description
fileId	string	Yes	The storage key returned by POST /api/uploads for the source PDF.
toFormat	string	Yes	Must be 'pdf'. Accepted: "pdf"
jobIntent	string	Yes	Must be set to 'transform' to allow same-format PDF optimization. Accepted: "transform"
options.metadata	string	No	Strips internal author, title, and creation timestamp metadata. Accepted: "remove" \| "keep"
options.pageRange	string	No	Extracts and optimizes only specified pages (e.g. '1-5' or 'all'). Accepted: Expression like "1-5" or "all"

HTTP

Error Code

Cause & Resolution

400

SAME_FORMAT_NOOP

Missing jobIntent: 'transform' in request body.

400

CORRUPT_FILE

Uploaded PDF file is corrupted or cannot be parsed by pdf-lib.

413

FILE_TOO_LARGE

PDF document exceeds max upload size limit for plan.

Code Examples

# Optimize and compress a PDF document by stripping metadata
curl -X POST "https://api.orbconvert.com/api/conversions" \
  -H "Authorization: Bearer <API_KEY>" \
  -H "Content-Type: application/json" \
  -d '{
    "fileId": "<FILE_ID>",
    "toFormat": "pdf",
    "jobIntent": "transform",
    "options": {
      "metadata": "remove"
    }
  }'