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Linearize PDFs to enable Fast Web View and byte-streaming in browsers. Our API restructures PDF files so the first page renders instantly while remaining pages stream in the background. No more waiting for entire files to download before viewing, improving user experience for online document viewing. Standard PDFs require the entire file to download before displaying any content linearly. Linearized PDFs reorganize internal structure to support byte-range requests, letting browsers fetch and display pages on demand. Users can start reading immediately and scroll through documents as they load.
Built for web applications serving PDFs, content management systems (CMS), online document viewers, e-learning platforms, and any service where documents are viewed in browsers. Automate linearization in your pipelines to optimize all PDFs for web delivery with asynchronous processing and webhook notifications to ensure all documents load quickly for end users.
Restructures PDFs for progressive streaming in web browsers. Users can read the first page instantly while remaining pages load in the background, turning multi-megabyte documents into instantly accessible content even on slower connections.
Reorganizes PDF internal structure to enable byte-range requests and incremental access. Page data and metadata are reordered so browsers can render content before downloading the full file, supporting true page-by-page streaming over network connections.
Enables true page-by-page streaming in modern browsers and PDF viewers. Users can start reading immediately and navigate through documents while they're still loading.
If you don't want to poll for task status, you can simply provide the webhook data in your request. Instead of manually checking status, we will automatically notify your endpoint the moment the task processing is completed.
destroy parameter, your files are permanently wiped from our servers immediately after processing finishes, ensuring complete data security. If destroy is not set, files are retained up to 30 days based on user's plan.Handle heavy documents and high-resolution assets with ease. Our API supports a massive 1GB payload size per request, allowing you to process even the largest PDF files without worrying about size restrictions.
$ pip install requests
File uploads must use multipart/form-data format. PDF API accepts a single file upload.
| Parameter | Required | Type | Default | Description |
|---|---|---|---|---|
| file | No | multipart/form-data | - | The PDF file to process. Only used if you're uploading a file instead of using file_id. |
Input Priority Rule:
If both file and file_id are provided, the multipart file upload takes priority and file_id is ignored.
All parameters must be included as query parameters. Any parameters sent in the form data will be ignored.
| Parameter | Required | Type | Default | Description |
|---|---|---|---|---|
| file_id | No | String | - | The unique ID of a PDF file already present on our server. Use this instead of uploading the file again. Either file or file_id must be provided. |
| output | No | String | linearized_pdf | Name of the output PDF (without extension). |
| destroy | No | Boolean | false | If true, we delete the input file immediately after generating the linearized output. |
| Parameter | Required | Type | Default | Description |
|---|---|---|---|---|
| webhook_url | No | String | - | The URL where we'll send the webhook notification after the task completes. Authentication parameters in the URL (e.g., ?auth=token123) are passed as-is. |
| webhook_failure_notification | No | Boolean | false | If true, we'll send an email notification if the webhook request fails after 3 retries. The email goes to the requesting user or their org admin if user is part of an organization. |
| Header | Required | Type | Default | Description |
|---|---|---|---|---|
| X-Webhook-Authorization | No | String | - | Custom authorization header sent with the webhook request. Format: Key:Value (e.g., Authorization:Bearer token123). |
Explore detailed response fields including field names, data types, requirements, and descriptions in the interactive Response Table below. For complete response documentation click here.
Use these endpoints to manage files and check task status.
task_id. The response includes creation and expiry timestamps to help you track result availability, along with specific error details if a task fails. Results are retained for up to 7 days, depending on the operation.file_id. Returns details including file name, size, type, and creation/deletion timestamps. Generated or uploaded files are retained up to 30 days based on user's plan, unless destroy is enabled to delete them immediately. You can use this endpoint to check if the file has expired using its file_id.multipart/form-data request. Each file receives a unique file_id that can be used with the PDF APIs.file_id for uses with the PDF APIs.| HTTP Status | Reasons |
|---|---|
| 400 | Invalid PDF File: Please provide a valid PDF file. We don't support other types. |
| 400 | Missing File or ID: You must provide either a file or a file ID. |
| 400 | Invalid Parameter: The value for 'param_name' is invalid. |
| 404 | File ID Not Found: Please provide a valid file ID. |
| 500 | File Saving Exception: An unknown error occurred while saving. Try again later. |
| 500 | Internal Server Error: Internal Server Error Occurred. |
These errors might appear in the task-status response if the background job fails.
| Error | Description |
|---|---|
Invalid PDF File | The provided file is not a valid PDF file. |
File Saving Exception | An unknown error occurred while saving the file. Try again later. |
PDF Generation Exception | An unknown error occurred while generating the PDF. Try again later. |
Internal Server Error | Internal Server Error Occurred. |
Encrypted PDF Provided | The provided PDF file is encrypted. Please decrypt it first to perform operations. |
Upload a PDF and linearize it to enable fast web view. The API restructures the file so browsers can display the first page immediately.
# Standard Response { "taskId": "04a06cd5-158d-4191-a45b-6f58249c599d", "inputIds": [ "7a9e4b12-f3c8-4d56-b7e1-8c2f9d0a3e6f" ] } # Response with destroy=true (No File IDs as they are deleted right away) { "taskId": "04a06cd5-158d-4191-a45b-6f58249c599d" }curl -X 'POST' \ 'https://api.apifreaks.com/v1.0/pdf/linearize?output=web_optimized' \ -H 'X-apiKey: YOUR_API_KEY' \ -F 'file=@/path/to/document.pdf'
Notes:
destroy=true to automatically delete the source file after linearizationAfter submitting a linearization task, check its progress using the Task Status API with your taskId. The task goes through these statuses: queued, processing, completed, and failed.
# Response (completed) { "taskId": "a1b2c3d4-e5f6-7890-a1b2-c3d4e5f67890", "status": "completed", "outputFileId": "9b2e7f3a-5c8d-4e1b-a6f9-0d3c8e7b2a5f", "outputFileName": "processed_document.pdf", "createdAt": "2025-01-26 10:30:00", "expiresAt": "2025-01-27 10:30:00" } # Response (failed) { "taskId": "a1b2c3d4-e5f6-7890-a1b2-c3d4e5f67890", "status": "failed", "error": "Invalid PDF File", "message": "The provided file is not a valid PDF file.", "createdAt": "2025-01-26 10:30:00" }curl -X GET "https://api.apifreaks.com/v1.0/pdf/task-status?taskId=a1b2c3d4-e5f6-7890-a1b2-c3d4e5f67890" \ -H "X-apikey: YOUR_API_KEY"
Once the task status shows “completed”, download your linearized PDF using the File Download API with the outputFileId from the task status response.
curl -X GET "https://api.apifreaks.com/v1.0/pdf/download?fileId=a7b8c9d0-e1f2-3456-a7b8-c9d0e1f23456" \ -H "X-apikey: YOUR_API_KEY" \ --output output.pdf
Get automatic notifications when your task completes instead of polling the task status endpoint. Good for event-driven applications and real-time document processing.
Add webhook_url to your request. We'll send a POST request to this URL when the task finishes (either completed or failed).
Example Request:
# Response { "taskId": "04a06cd5-158d-4191-a45b-6f58249c599d", "inputIds": [ "566dc743-d8fe-4943-8cef-61e5d3d6096c" ] }curl -X 'POST' \ 'https://api.apifreaks.com/v1.0/pdf/linearize?output=web_optimized&webhook_url=https://yourdomain.com/webhook/pdf-linearize&webhook_failure_notification=true' \ -H 'X-apiKey: YOUR_API_KEY' \ -F 'file=@/path/to/document.pdf'
Webhook delivery will be attempted up to 3 times. If all retries fail and webhook_failure_notification is enabled, we'll send an email notification to the requesting user or their organization admin.
Use X-Webhook-Authorization to add a custom header to webhook requests for endpoint security.
Format: Key:Value
Example: If you send Authorization:Bearer token123, the webhook request will include: Authorization: Bearer token123
Example with custom authorization:
curl -X 'POST' \ 'https://api.apifreaks.com/v1.0/pdf/linearize?webhook_url=https://yourdomain.com/webhook/pdf-linearize&webhook_failure_notification=true' \ -H 'X-apiKey: YOUR_API_KEY' \ -H 'X-Webhook-Authorization: Authorization:Bearer token123' \ -F 'file=@/path/to/document.pdf'
When your task completes, we send a POST request to your webhook_url with these headers:
| Header | Description | Example |
|---|---|---|
Content-Type | Always application/json | application/json |
X-Signature | HMAC-SHA256 signature of the request body using your API key. Use this to verify the payload is authentic. | 4a7d1ed414474e4033ac29ccb8653d9b |
| Custom Header | (If provided) Your custom header from X-Webhook-Authorization | Authorization: Bearer token123 |
The webhook payload contains the same response structure as the Task Status API endpoint when checked for the task ID. For a comprehensive view of the webhook response structure and detailed field descriptions, explore the interactive Response Table.
Use the X-Signature header to verify webhook requests actually came from API Freaks and weren't tampered with.
How the signature works:
X-Signature header valueTo verify the webhook:
X-Signature header valueImportant: Don't transform or process the raw request body before verification. Adding whitespace or other formatting creates a different signature and verification will fail.
To use the PDF Linearize API, API credits are required. Charges apply only for successful queries, defined by a 2xx status code. If a request results in a 4xx or 5xx status code, no credits will be deducted, and any credits already charged will be refunded.
For each successful request, 200 credit will be charged. 1 extra credit will be charged per MB beyond 50 MB.
Utilize the Credits Usage API to efficiently monitor your recent consumption of both one-off and subscription credits. This API provides a streamlined way to track and manage your credit usage, ensuring you stay informed about your remaining balance and can optimize your resource allocation effectively.