> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pdf4llm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Saving Output

> Write extracted Markdown, JSON, and plain text to disk using System.IO.

<div id="apiIndicatorBadge">
  <div class="inner dotnet" />
</div>

## Overview

PDF4LLM's extraction methods return plain .NET strings — writing them to disk is handled by the standard library. The recommended approach is `System.IO.File.WriteAllText()`, which is straightforward, cross-platform, and available without additional dependencies.

***

## Saving Markdown

```csharp theme={null}
using System.IO;
using PDF4LLM;

string mdText = PdfExtractor.ToMarkdown("document.pdf");
File.WriteAllText("output.md", mdText, System.Text.Encoding.UTF8);
```

<Tip>
  Always pass `System.Text.Encoding.UTF8` explicitly when writing text files. The two-argument overload of `File.WriteAllText` uses the platform default encoding, which can silently corrupt special characters, symbols, and non-Latin scripts on Windows.
</Tip>

***

## Saving JSON

`ToJson()` returns a JSON string directly — no additional serialisation step is needed:

```csharp theme={null}
using System.IO;
using PDF4LLM;

string json = PdfExtractor.ToJson("document.pdf");
File.WriteAllText("output.json", json, System.Text.Encoding.UTF8);
```

The returned JSON is compact by default. To write human-readable indented JSON, round-trip it through `System.Text.Json`:

```csharp theme={null}
using System.IO;
using System.Text.Json;
using PDF4LLM;

string   json        = PdfExtractor.ToJson("document.pdf");
var      parsed      = JsonSerializer.Deserialize<object>(json);
string   indented    = JsonSerializer.Serialize(parsed, new JsonSerializerOptions { WriteIndented = true });

File.WriteAllText("output.json", indented, System.Text.Encoding.UTF8);
```

For large documents where file size matters, skip the indentation step and write the compact string directly.

***

## Saving plain text

```csharp theme={null}
using System.IO;
using PDF4LLM;

string text = PdfExtractor.ToText("document.pdf");
File.WriteAllText("output.txt", text, System.Text.Encoding.UTF8);
```

***

## Saving per-page chunks

When using `LlamaMarkdownReader`, save each page as a separate file using the page number from the chunk metadata to name each file:

```csharp theme={null}
using System.IO;
using PDF4LLM;

string outputDir = "output/pages";
Directory.CreateDirectory(outputDir);

var reader = PdfExtractor.LlamaMarkdownReader();
var chunks = reader.LoadData("document.pdf");

foreach (var chunk in chunks)
{
    int    pageNum  = (int)chunk.ExtraInfo["page"];
    string filePath = Path.Combine(outputDir, $"page-{pageNum}.md");

    File.WriteAllText(filePath, chunk.Text, System.Text.Encoding.UTF8);
    Console.WriteLine($"Saved {filePath}");
}
```

***

## Saving with a matching filename

To derive the output filename from the input document automatically:

```csharp theme={null}
using System.IO;
using PDF4LLM;

string inputPath  = "reports/annual-report-2025.pdf";
string mdText     = PdfExtractor.ToMarkdown(inputPath);

string outputPath = Path.ChangeExtension(inputPath, ".md");
File.WriteAllText(outputPath, mdText, System.Text.Encoding.UTF8);

Console.WriteLine($"Saved to {outputPath}");
// Saved to reports/annual-report-2025.md
```

`Path.ChangeExtension()` swaps the file extension cleanly, keeping the same directory and stem.

***

## Saving to a different directory

To write output to a different folder while keeping the original filename:

```csharp theme={null}
using System.IO;
using PDF4LLM;

string inputPath  = "source/document.pdf";
string outputDir  = "extracted";
Directory.CreateDirectory(outputDir);

string mdText     = PdfExtractor.ToMarkdown(inputPath);
string outputName = Path.ChangeExtension(Path.GetFileName(inputPath), ".md");
string outputPath = Path.Combine(outputDir, outputName);

File.WriteAllText(outputPath, mdText, System.Text.Encoding.UTF8);

Console.WriteLine($"Saved to {outputPath}");
// Saved to extracted/document.md
```

***

## Processing multiple files

To extract and save output for an entire folder of PDFs:

```csharp theme={null}
using System.IO;
using PDF4LLM;

string inputDir  = "documents/";
string outputDir = "extracted/";
Directory.CreateDirectory(outputDir);

string[] pdfFiles = Directory.GetFiles(inputDir, "*.pdf");
Console.WriteLine($"Found {pdfFiles.Length} PDF(s)");

foreach (string pdfPath in pdfFiles)
{
    Console.WriteLine($"Processing {Path.GetFileName(pdfPath)}...");
    try
    {
        string mdText     = PdfExtractor.ToMarkdown(pdfPath);
        string outputName = Path.ChangeExtension(Path.GetFileName(pdfPath), ".md");
        string outputPath = Path.Combine(outputDir, outputName);

        File.WriteAllText(outputPath, mdText, System.Text.Encoding.UTF8);
        Console.WriteLine($"  ✓ Saved to {outputPath}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"  ✗ Failed: {ex.Message}");
    }
}

Console.WriteLine("Done.");
```

***

## Saving images alongside Markdown

When `writeImages: true` is used, image files are written to disk automatically during extraction. Create the image directory first, then save the Markdown file alongside it:

```csharp theme={null}
using System.IO;
using PDF4LLM;

string imageDir = "output/images";
Directory.CreateDirectory(imageDir);

string mdText = PdfExtractor.ToMarkdown(
    "document.pdf",
    writeImages:  true,
    imagePath:    imageDir,
    imageFormat:  "png"
);

File.WriteAllText("output/document.md", mdText, System.Text.Encoding.UTF8);
```

<Note>
  Image paths in the Markdown output are relative to wherever the `.md` file is opened from. Keep your Markdown file and image directory in the same parent folder to ensure image links resolve correctly.
</Note>

***

## File format summary

| Output          | Method                           | Extension       | How to write                         |
| --------------- | -------------------------------- | --------------- | ------------------------------------ |
| Markdown        | `ToMarkdown()`                   | `.md`           | `File.WriteAllText()`                |
| JSON            | `ToJson()`                       | `.json`         | `File.WriteAllText()` directly       |
| Plain text      | `ToText()`                       | `.txt`          | `File.WriteAllText()`                |
| Per-page chunks | `LlamaMarkdownReader.LoadData()` | `.md` per page  | `File.WriteAllText()` in a loop      |
| Images          | `ToMarkdown(writeImages: true)`  | `.png` / `.jpg` | Written automatically to `imagePath` |

***

## Next steps

<CardGroup cols={2}>
  <Card title="Extract Markdown" icon="markdown" href="/dotnet/guides/extract-Markdown">
    Full walkthrough of ToMarkdown() with all common options.
  </Card>

  <Card title="Extract JSON" icon="brackets-curly" href="/dotnet/guides/extract-JSON">
    Bounding boxes and layout data for custom pipelines.
  </Card>

  <Card title="Extract Text" icon="align-left" href="/dotnet/guides/extract-Text">
    Plain text extraction and whitespace handling.
  </Card>

  <Card title="Images & Graphics" icon="image" href="/dotnet/guides/images-and-graphics">
    Controlling image extraction, format, and output path.
  </Card>
</CardGroup>