Convert a Document to PDF

Purpose Summary. What is this page about?

This page demonstrates how to use Aspose.Words for Python via .NET to convert various document types—including Word files, images, and other supported formats—to PDF, covering basic conversion, PDF compliance options, and output size optimization.

The ability to easily and reliably convert documents from one format to another is a key feature of Aspose.Words. One of the most popular formats for converting is PDF – a fixed-layout format, which preserves the original appearance of a document during its rendering on various platforms. The “rendering” term is used in Aspose.Words to describe the process of converting a document into a file format that is paginated or has the concept of pages.

Convert a Word Document to PDF

Conversion from Word to PDF is a rather complex process that requires several stages of calculation. Aspose.Words layout engine mimics the way Microsoft Word’s page layout engine works, making PDF output documents look as close as possible to what you can see in Microsoft Word.

With Aspose.Words you can programmatically convert a document from Word formats, such as DOC or DOCX, to PDF without using Microsoft Office. This article explains how to perform this conversion.

Note that the number of pages in a document affects the conversion time.

Convert DOCX or DOC to PDF

Converting from the DOC or DOCX document format into the PDF format in Aspose.Words is very easy and can be accomplished with just two lines of code that:

Load your document into a Document object using one of its constructors by specifying the document name with its format extension.
Invoke one of the Document.save methods on the Document object and specify the desired output format as PDF by entering a file name with the “.PDF” extension.

The following code example shows how to convert a document from DOCX into PDF using the save method:

You can download the template file of this example from Aspose.Words GitHub.

Sometimes it is necessary to specify additional options, which can affect the result of saving a document as a PDF. These options can be specified using the PdfSaveOptions class, containing properties that determine how the PDF output will be displayed.

Note that with the same technique, you can convert any flow-layout format document to PDF format.

Convert to Different PDF Standards

Aspose.Words provides the PdfCompliance enumeration to support the conversion of DOC or DOCX into various PDF format standards (such as PDF 1.7, PDF 1.5, etc.).

The following code example demonstrates how to convert a document to PDF 1.7 using PdfSaveOptions with compliance to PDF17:

Convert Images to PDF

Converting to PDF is not restricted by Microsoft Word document formats. Any format supported by Aspose.Words, including programmatically created, can also be converted to PDF. For example, we can convert single-page images, such as JPEG, PNG, BMP, EMF, or WMF, as well as multi-page images, such as TIFF and GIF, to PDF.

The following code example shows how to convert JPEG and TIFF images to PDF:

To make this code work, you need to add references to Aspose.Words and aspose.pydrawing to your project.

Reduce PDF Output Size

When saving to PDF, you can specify whether you want to optimize the output. To do this, you need to set the optimize_output flag to true, and then redundant nested canvases and empty canvases will be removed, neighbor glyphs with the same formatting will be concatenated.

The following code example shows how to optimize the output:

Using the optimize_output property may affect the accuracy of content display.

Limitations and Considerations

Converting large or complex documents to PDF may be time- and memory-intensive.
Rendering fidelity depends on the availability of fonts — missing fonts are substituted based on system settings.
PDF/A and PDF/UA compliance imposes additional requirements: all fonts must be embedded, color spaces must be valid, and content must meet accessibility standards.
Using OptimizeOutput may slightly affect visual fidelity by merging glyphs or removing empty canvases.
Some advanced Word features (e.g., certain drawing objects, complex table layouts, or field codes) may not render identically to Microsoft Word.

PdfSaveOptions class
PdfCompliance enumeration
Document.Save) method
OptimizeOutput property

FAQ

Q: How do I convert a DOCX file to PDF using Aspose.Words for Python via .NET?
A: Load the DOCX into a Document object and call its save method with a filename that ends with .pdf. Example:
```
from aspose.words import Document
doc = Document("input.docx")
doc.save("output.pdf")
```
Q: How can I create a PDF that complies with a specific PDF standard (e.g., PDF 1.7)?
A: Use PdfSaveOptions and set its compliance property to the desired PdfCompliance value before saving. Example:
```
doc = aw.Document("input.docx")
options = aw.saving.PdfSaveOptions()
options.compliance = PdfCompliance.PDF17
doc.save("output.pdf", options)
```
Q: What is the recommended way to reduce the size of the generated PDF?
A: Enable the optimize_output flag in FixedPageSaveOptions (or PdfSaveOptions). This removes redundant canvases and merges identical glyphs. Example:
```
doc = aw.Document("input.docx")
options = aw.saving.PdfSaveOptions()
options.optimize_output = True
doc.save("output.pdf", options)
```
Q: Can I convert image files such as JPEG, PNG, or multi‑page TIFF to PDF?
A: Yes. Load the image using Document (or Image for multi‑page formats) and save it as PDF. Example for a JPEG:
```
doc = aw.Document("photo.jpg")
doc.save("photo.pdf")
```
Q: Is it possible to convert multiple images (e.g., a set of PNG files) into a single PDF document?
A: Create a new Document, insert each image as a separate section or page using DocumentBuilder, then save the document as PDF. Example:
```
pdf_doc = aw.Document()
builder = aw.DocumentBuilder(pdf_doc)
for image_path in ["page1.png", "page2.png"]:
    builder.insert_image(image_path)
    builder.insert_break()
pdf_doc.save("combined.pdf")
```

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