--- title: "PDF rendering server | Nutrient SDK" canonical_url: "https://www.nutrient.io/guides/document-engine/rendering/" md_url: "https://www.nutrient.io/guides/document-engine/rendering.md" last_updated: "2026-05-22T14:49:21.619Z" description: "Learn to render single or multiple document pages as images using Nutrient Document Engine's PDF Rendering Server API. Control output dimensions and formats efficiently." --- # PDF rendering server To render pages in a document, post a multipart request to the [`/api/build` API endpoint][], including the desired page index or indexes in the `instructions.output.pages` field. To learn more about the schema for `/build` `instructions`, go to the [API Reference](https://www.nutrient.io/api/reference/document-engine/upstream/#tag/Build-API). In the `/api/build` request, set the `instructions.output.type` parameter to `image`. By default, the `output.type` for `/build` instructions is set to `pdf`. The page index is provided via the [`instructions.output.pages` field](https://www.nutrient.io/api/reference/document-engine/upstream/#model/BuildInstructions), and the rendered dimensions are provided via a [`width`, `height`, or `dpi` option](https://www.nutrient.io/api/reference/document-engine/upstream/#model/BuildInstructions). To learn more about available options for rendering, go to the [API Reference](https://www.nutrient.io/api/reference/document-engine/upstream/#tag/Build-API). Only one option — `width`, `height`, or `dpi` — can be chosen. Other dimensions are calculated before rendering, so as to preserve the page aspect ratio of the rendered image. The format of the rendered image can be controlled via the [`format` option](https://www.nutrient.io/api/reference/document-engine/upstream/#model/BuildInstructions). Supported image formats are PNG, JPEG, WebP, and TIFF. - Ensure [Document Engine is up and running](https://www.nutrient.io/sdk/document-engine/getting-started.md). - Send a [multipart POST request](https://www.baeldung.com/postman-form-data-raw-x-www-form-urlencoded) with [instructions](https://www.nutrient.io/api/reference/document-engine/upstream/#tag/Build-API) to Document Engine’s `/api/build` endpoint. For more information, refer to the [API reference](https://www.nutrient.io/api/reference/document-engine/upstream/#tag/Build-API) to learn about the `/api/build` endpoint and all the actions you can perform on PDFs with Document Engine. For an overview of multipart requests, refer to the [brief tour of multipart requests](https://www.nutrient.io/blog/a-brief-tour-of-multipart-requests/) blog post. ## Rendering a page of a file on disk You can render a single page or multiple pages of a document. ### Rendering a single page The following example renders the second page (with index `1`) of a document. The response to this request is a PNG image file: ### SHELL ```shell curl -X POST http://localhost:5000/api/build \ -H "Authorization: Token token=" \ -F document=@/path/to/example-document.pdf \ -F instructions='{ "parts": [ { "file": "document" } ], "output": { "type": "image", "format": "png", "pages": { "start": 1, "end": 1 } } }' \ -o output-image.png ``` ### HTTP ```http POST /api/build HTTP/1.1 Content-Type: multipart/form-data; boundary=customboundary Authorization: Token token= --customboundary Content-Disposition: form-data; name="document"; filename="example-document.pdf" Content-Type: application/pdf --customboundary Content-Disposition: form-data; name="instructions" Content-Type: application/json { "parts": [ { "file": "document" } ], "output": { "type": "image", "format": "png", "pages": { "start": 1, "end": 1 } } } --customboundary-- ``` ### Rendering multiple pages The following example renders the first, second, and third page (indexes `0`, `1` and `2`) of a document. The response to this request is a ZIP file containing all the images: ### SHELL ```shell curl -X POST http://localhost:5000/api/build \ -H "Authorization: Token token=" \ -F document=@/path/to/example-document.pdf \ -F instructions='{ "parts": [ { "file": "document" } ], "output": { "type": "image", "format": "png", "pages": { "start": 0, "end": 2 } } }' \ -o result.zip ``` ### HTTP ```http POST /api/build HTTP/1.1 Content-Type: multipart/form-data; boundary=customboundary Authorization: Token token= --customboundary Content-Disposition: form-data; name="document"; filename="example-document.pdf" Content-Type: application/pdf --customboundary Content-Disposition: form-data; name="instructions" Content-Type: application/json { "parts": [ { "file": "document" } ], "output": { "type": "image", "format": "png", "pages": { "start": 0, "end": 2 } } } --customboundary-- ``` ## Rendering a page of a file from a URL You can specify the document to render by providing a URL to the document instead of a path to the file: ### SHELL ```shell curl -X POST http://localhost:5000/api/build \ -H "Authorization: Token token=" \ -F instructions='{ "parts": [ { "file": { "url": "https://pspdfkit.com/downloads/examples/paper.pdf" } } ], "output": { "type": "image", "format": "png", "pages": { "start": 1, "end": 1 } } }' \ -o output-image.png ``` ### HTTP ```http POST /api/build HTTP/1.1 Content-Type: multipart/form-data; boundary=customboundary Authorization: Token token= --customboundary Content-Disposition: form-data; name="instructions" Content-Type: application/json { "parts": [ { "file": { "url": "https://pspdfkit.com/downloads/examples/paper.pdf" } } ], "output": { "type": "image", "format": "png", "pages": { "start": 1, "end": 1 } } } --customboundary-- ``` --- ## Related pages - [Changelog for Document Engine](/guides/document-engine/changelog.md) - [Demo: Document Engine](/guides/document-engine/demo.md) - [Download Document Engine](/guides/document-engine/downloads.md) - [Example projects](/guides/document-engine/example-projects.md) - [Document Engine PDF server](/guides/document-engine.md) - [Developer guides](/guides/document-engine/intro.md) - [Knowledge base](/guides/document-engine/kb.md) - [Nightly build](/guides/document-engine/nightly.md) - [Troubleshooting](/guides/document-engine/troubleshoot.md)