Generation and Conversion

March 14, 2026 · View on GitHub

Use these patterns when the main task is to generate a new document or convert an existing one into another format.

HTML to PDF generation

Upload the HTML file and reference it through parts[].html.

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F index.html=@index.html \
  -F 'instructions={"parts":[{"html":"index.html"}]}' \
  -o result.pdf

With layout options:

{
  "parts": [{ "html": "index.html" }],
  "output": {
    "type": "pdf",
    "layout": {
      "orientation": "landscape",
      "size": "A4",
      "margin": { "top": 20, "bottom": 20, "left": 15, "right": 15 }
    }
  }
}

Remote URL generation or conversion

When the input already lives at a stable remote URL, send a JSON request and use file.url:

curl -X POST https://api.nutrient.io/build \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -d '{
    "parts": [
      {
        "file": {
          "url": "https://www.nutrient.io/api/assets/downloads/samples/docx/document.docx"
        }
      }
    ]
  }' \
  -o result.pdf

Use this pattern when you want server-side fetches and do not need to upload a local file first.

Office to PDF

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F document.docx=@document.docx \
  -F 'instructions={"parts":[{"file":"document.docx"}]}' \
  -o result.pdf

Supported common inputs: docx, xlsx, pptx, doc, xls, ppt, odt, ods, odp, rtf

Image to PDF

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F photo.jpg=@photo.jpg \
  -F 'instructions={"parts":[{"file":"photo.jpg"}]}' \
  -o result.pdf

Supported common images: jpg, jpeg, png, gif, webp, tiff, bmp

PDF to Office

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F document.pdf=@document.pdf \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"output":{"type":"docx"}}' \
  -o result.docx

Supported common outputs: docx, xlsx, pptx

PDF to image

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F document.pdf=@document.pdf \
  -F 'instructions={"parts":[{"file":"document.pdf","pages":{"start":0,"end":0}}],"output":{"type":"png","dpi":150}}' \
  -o page.png

Useful output options:

Option	Meaning
`type`	`png`, `jpeg`, or `webp`
`dpi`	Resolution target
`width` / `height`	Explicit pixel size

Generation and conversion rules

Use HTML generation when you control the markup and need stable, reproducible output.
Use remote URL requests when the source already exists online and you want to avoid local uploads.
Use output.type for direct conversions. Do not create unnecessary actions for simple format changes.
For paginated image output, render only the pages you need.