POSThttps://app.alternapdf.com/api/v1/convert/pdf-to-image

PDF to Image

Render PDF pages as high-quality images. Supports PNG, JPEG, and WebP output formats with configurable DPI, quality, and dimensions. Request a single page to receive an image file directly, or a page range to receive a ZIP archive containing all rendered pages.

Content-Type: multipart/form-data

Parameters

Parameter	Type	Default	Description
`file` required	file	—	The PDF file to render as images.
`page_number`	integer	`1`	Render a single specific page. Use this for single-page output.
`start_page`	integer	—	First page of a range to render. Used with `end_page` for multi-page output (ZIP).
`end_page`	integer	—	Last page of a range to render. Used with `start_page` for multi-page output (ZIP).
`image_format`	string	`PNG`	Output image format. Options: `PNG`, `JPEG`, `WEBP`.
`dpi`	integer	`150`	Resolution in dots per inch. Options: `72`, `150`, `300`.
`quality`	integer	`85`	Image quality (1-100). Applies to JPEG and WebP formats.
`transparent_background`	boolean	`false`	Use a transparent background instead of white. PNG format only.
`custom_width`	integer	—	Custom output width in pixels. Aspect ratio is maintained if only width is set.
`custom_height`	integer	—	Custom output height in pixels. Aspect ratio is maintained if only height is set.

Code Examples

cURL

# Single page - returns an image file
curl -X POST "https://app.alternapdf.com/api/v1/convert/pdf-to-image" \
  -H "X-API-Key: YOUR_API_KEY" \
  -F "file=@document.pdf" \
  -F "page_number=1" \
  -F "image_format=PNG" \
  -F "dpi=300" \
  --output page1.png

# Multiple pages - returns a ZIP archive
curl -X POST "https://app.alternapdf.com/api/v1/convert/pdf-to-image" \
  -H "X-API-Key: YOUR_API_KEY" \
  -F "file=@document.pdf" \
  -F "start_page=1" \
  -F "end_page=5" \
  -F "image_format=JPEG" \
  -F "quality=90" \
  --output pages.zip

Python

import requests

url = "https://app.alternapdf.com/api/v1/convert/pdf-to-image"
headers = {"X-API-Key": "YOUR_API_KEY"}

# Single page rendering
with open("document.pdf", "rb") as f:
    files = {"file": ("document.pdf", f, "application/pdf")}
    data = {
        "page_number": "1",
        "image_format": "PNG",
        "dpi": "300",
    }
    response = requests.post(url, headers=headers, files=files, data=data)

with open("page1.png", "wb") as out:
    out.write(response.content)

# Multi-page rendering (returns ZIP)
with open("document.pdf", "rb") as f:
    files = {"file": ("document.pdf", f, "application/pdf")}
    data = {
        "start_page": "1",
        "end_page": "5",
        "image_format": "JPEG",
        "quality": "90",
    }
    response = requests.post(url, headers=headers, files=files, data=data)

with open("pages.zip", "wb") as out:
    out.write(response.content)

JavaScript

import fs from "fs";

const formData = new FormData();
formData.append("file", fs.createReadStream("document.pdf"));
formData.append("page_number", "1");
formData.append("image_format", "PNG");
formData.append("dpi", "300");

const response = await fetch("https://app.alternapdf.com/api/v1/convert/pdf-to-image", {
  method: "POST",
  headers: {
    "X-API-Key": "YOUR_API_KEY",
  },
  body: formData,
});

const buffer = await response.arrayBuffer();
fs.writeFileSync("page1.png", Buffer.from(buffer));

// Multi-page rendering (returns ZIP)
const multiFormData = new FormData();
multiFormData.append("file", fs.createReadStream("document.pdf"));
multiFormData.append("start_page", "1");
multiFormData.append("end_page", "5");
multiFormData.append("image_format", "JPEG");
multiFormData.append("quality", "90");

const multiResponse = await fetch("https://app.alternapdf.com/api/v1/convert/pdf-to-image", {
  method: "POST",
  headers: {
    "X-API-Key": "YOUR_API_KEY",
  },
  body: multiFormData,
});

const zipBuffer = await multiResponse.arrayBuffer();
fs.writeFileSync("pages.zip", Buffer.from(zipBuffer));

Response

The response format depends on the number of pages requested:

Single Page

Returns the image file directly as a binary response.

Header	Value
`Content-Type`	`image/png`, `image/jpeg`, or `image/webp`
`Content-Disposition`	`attachment; filename="page_1.png"`

Multiple Pages

Returns a ZIP archive containing one image per page.

Header	Value
`Content-Type`	`application/zip`
`Content-Disposition`	`attachment; filename="document_pages.zip"`