Convert PDFs to Markdown for LLM-Ready Data with Marker
Easily convert complex PDFs into structured Markdown files for LLM-ready data. Learn how Marker, an open-source tool, can boost your PDF to Markdown conversion accuracy and speed compared to other options like Nougat. Optimize your dataset for language models with this efficient workflow.
February 17, 2025

Unlock the power of your PDF documents for your language models with Marker, an open-source tool that effortlessly converts complex PDFs into well-structured Markdown files. Streamline your data preparation process and unleash the full potential of your language models, regardless of the format of your source material.
The Challenges of Working with PDFs for LLM
The Benefits of Using Markdown for LLM
Introducing Marker: An Open-Source Tool to Convert PDFs to Markdown
Comparing Marker to Other PDF-to-Markdown Tools
How to Install and Use Marker
Marker's Capabilities and Limitations
Conclusion
The Challenges of Working with PDFs for LLM
The Challenges of Working with PDFs for LLM
Working with PDFs for large language model (LLM) applications can be extremely challenging. PDFs are essentially a "broken" format, as they often have a complex structure with nested elements of different data types, and there is no standard layout, making it cumbersome to extract data from them.
Some of the key challenges include:
-
Complex Structure: PDFs can have a nested structure with different data types, such as text, tables, images, and equations, making it difficult to parse and extract the relevant information.
-
Lack of Standardization: There is no standard layout for PDFs, which means that the data can be organized in various ways, making it difficult to develop a one-size-fits-all solution for extracting the information.
-
Encoding and Formatting Issues: PDFs can have different encodings and formatting, such as different fonts and layouts, which can further complicate the data extraction process.
-
Tables and Images: Extracting data from tables and images within PDFs can be particularly challenging, as the layout and formatting of these elements can vary significantly.
-
Errors and Inaccuracies: The process of extracting data from PDFs is prone to errors and inaccuracies, which can negatively impact the performance of LLM applications.
To make PDFs more LLM-ready, various approaches have been explored, such as converting PDFs to plain text, using machine learning models to detect the layout, and employing optical character recognition (OCR) techniques. However, these methods can be cumbersome and still prone to errors.
In contrast, working with Markdown, a lightweight markup language, can be much easier for LLM applications. Markdown can retain the original formatting, including titles, headers, images, tables, and equations, which can be effectively processed by LLMs.
The Benefits of Using Markdown for LLM
The Benefits of Using Markdown for LLM
Markdown is a lightweight markup language that offers several benefits when working with Large Language Models (LLMs):
-
Structured Data: Markdown retains the original formatting of the document, including titles, headers, images, tables, and equations. This structured data can be effectively processed by LLMs, allowing them to understand the context and relationships within the content.
-
Ease of Conversion: Converting PDF files, which are often the primary source of text data, to plain text can be a cumbersome task due to the complex structure and formatting of PDFs. Markdown, on the other hand, can be easily converted to plain text, making it a more LLM-friendly format.
-
Consistency: Markdown provides a consistent and standardized way of formatting text, which can be particularly useful when working with large datasets or multiple documents. This consistency can improve the performance and reliability of LLM applications.
-
Readability: Markdown's simple syntax and clean formatting make the text more readable and accessible, both for humans and machines. This can facilitate better understanding and interpretation of the content by LLMs.
-
Portability: Markdown files are lightweight and can be easily shared, stored, and version-controlled, making them a versatile choice for LLM applications that require data portability and collaboration.
-
Flexibility: Markdown can be easily integrated with various tools and workflows, allowing for seamless integration with LLM pipelines and other data processing tasks.
By leveraging the benefits of Markdown, you can improve the quality and performance of your LLM applications, making it a valuable choice for data preparation and management.
Introducing Marker: An Open-Source Tool to Convert PDFs to Markdown
Introducing Marker: An Open-Source Tool to Convert PDFs to Markdown
Marker is an open-source tool that allows you to quickly and accurately convert complex PDF files into well-structured Markdown. This is particularly useful when working with large language models (LLMs), as Markdown provides a clean and easily processable format compared to the challenges posed by PDFs.
Marker supports a wide range of document types, including books, scientific papers, and even resumes. It is optimized to handle the complexities of PDF structures, removing headers, footers, and other artifacts to extract the core content. Additionally, Marker formats tables, code blocks, and equations (converting most to LaTeX), and saves any images found in the original document.
One of the key advantages of Marker is its performance. Compared to other open-source tools like Nougat, Marker is significantly faster, taking around 100 seconds to process a single page of text, compared to 400 seconds for Nougat. Marker also demonstrates higher accuracy, preserving the structure and layout of the original document more effectively.
While Marker is not perfect and may encounter some limitations with complex equations or table formatting, it provides a robust and reliable solution for converting PDFs to Markdown. The tool is open-source and available for use, with some commercial usage restrictions for organizations with higher revenue or funding.
To get started with Marker, you can follow the installation instructions, which involve setting up a new Conda environment and installing PyTorch. Once installed, you can use the provided commands to convert single PDF files or multiple files in a batch. Marker will handle the layout analysis, text extraction, and Markdown formatting, making it a valuable tool for anyone working with LLMs and needing to process large amounts of PDF data.
Comparing Marker to Other PDF-to-Markdown Tools
Comparing Marker to Other PDF-to-Markdown Tools
Marker is an open-source tool that offers several advantages over other PDF-to-Markdown conversion tools. Compared to Nuget, another popular open-source option, Marker is much faster, taking around 100 seconds to process a single page of text, compared to 400 seconds for Nuget. Additionally, Marker's accuracy is nearly double that of Nuget.
The author provides a concrete example using the book "Think Python" to illustrate the differences. Nuget completely ignored the first few pages and the table of contents, while Marker was able to preserve the entire structure of the book, including the first few pages, table of contents, and the first chapter.
Marker supports a wide variety of document types, including books and scientific papers, and can handle documents in multiple languages. It removes headers, footers, and other artifacts, and formats tables and code blocks accurately. Marker also extracts and saves images, and can convert most equations to LaTeX format.
However, Marker is not without its limitations. It may not convert 100% of equations to LaTeX, and tables are not always formatted perfectly. Additionally, whitespace and line spans may not always be respected. Despite these limitations, Marker seems to work well on most PDF files and is a valuable open-source tool for converting PDF documents to structured Markdown.
How to Install and Use Marker
How to Install and Use Marker
To install and use the Marker tool, follow these steps:
-
Create a new Conda environment and name it
marker
:conda create -n marker python=3.9 conda activate marker
-
Install PyTorch, which is required by Marker:
# For Mac pip install torch torchvision torchaudio # For Linux # Use the appropriate command from the PyTorch website # For Windows # Use the appropriate command from the PyTorch website
-
Install the Marker package using pip:
pip install marker-pdf
-
To convert a single PDF file to Markdown, use the following command:
marker-single <path_to_pdf_file> <output_directory>
You can also specify optional parameters, such as the batch multiplier and the language of the document.
-
To convert multiple PDF files to Markdown, use the following command:
marker-multi <directory_with_pdf_files> <output_directory>
The Marker tool will first download the necessary OCR model, then process the PDF file(s) and generate Markdown files with the extracted content, including text, images, tables, and equations (when possible). The output will be stored in the specified output directory.
Note that Marker has some limitations, such as not always formatting tables correctly and not being able to convert 100% of equations to LaTeX. However, it provides a fast and accurate way to convert PDF files to structured Markdown, which can be very useful for working with PDF data in LLM applications.
Marker's Capabilities and Limitations
Marker's Capabilities and Limitations
Marker is an open-source tool that can effectively convert complex PDF files into well-structured Markdown format. Some of its key capabilities include:
- Supports a wide variety of documents, including books, scientific papers, and resumes.
- Optimized for extracting content from PDFs, removing headers, footers, and other artifacts.
- Formats tables and code blocks, extracts and saves images, and converts most equations to LaTeX.
- Runs on GPU, CPU, or Apple's MPS, with optional OCR support.
However, Marker also has some limitations:
- Not all equations will be converted to LaTeX with 100% accuracy.
- Tables are not always formatted perfectly, and some line spacing and spans may not be joined properly.
- There are usage restrictions for commercial projects exceeding certain revenue or funding thresholds.
Despite these limitations, Marker is a powerful tool that can significantly simplify the process of working with PDF data for language models and other applications. Its open-source nature and impressive performance make it a valuable resource for those looking to streamline their PDF-to-Markdown conversion workflows.
Conclusion
Conclusion
The availability of good data is crucial for the success of LLM applications. While PDF files are commonly used for storing text data, working with them can be extremely challenging due to their complex structure and lack of standardization.
Marker, an open-source tool, provides a solution to this problem by efficiently converting PDF files into well-structured Markdown format. Compared to other tools like Nuget, Marker is faster and more accurate in preserving the original document structure, including elements like headers, tables, images, and equations.
The tool supports a wide range of document types, including books, scientific papers, and resumes. It removes headers, footers, and other artifacts, and formats tables and code blocks effectively. While it may not handle 100% of equations or table formatting perfectly, Marker is a valuable tool that can significantly simplify the process of preparing PDF data for LLM applications.
Overall, Marker is a powerful open-source solution that can help overcome the challenges of working with PDF data and improve the quality of data used in LLM applications.
FAQ
FAQ