Return to site

What is 'Chunking' in generative AI?

January 12, 2025

Chunking in the context of generative AI and document parsing, such as processing PDFs, refers to the technique of dividing large pieces of text or information into smaller, manageable segments or “chunks.” This method is commonly used to make it easier for AI models to process and analyze data effectively, especially when dealing with long or complex documents. Here’s a closer look at how it works and its significance:

Why Chunking is Necessary

Generative AI models like GPTs have input length limitations, meaning they can only process a certain number of tokens (words or characters) at a time. A PDF document can often exceed these limits, especially if it contains hundreds of pages. Chunking allows developers to break the document into smaller pieces that fit within these constraints, ensuring the AI can work on each part without being overwhelmed or losing context.

How Chunking Works

When parsing a PDF, chunking typically involves dividing the text into logical sections such as paragraphs, pages, or specific themes. This can be done using delimiters like headings, line breaks, or by predefined character or token counts. For instance, a 10-page report might be divided into chunks of one page each, or by sections like “Introduction,” “Methodology,” and “Results.” Tools that extract text from PDFs often support automated chunking to streamline this process.

Applications in Generative AI

In generative AI, chunking enables models to:

  • Answer questions about specific parts of a document.
  • Summarize sections of text without needing to process the entire document simultaneously.
  • Maintain contextual relevance by focusing on smaller, coherent portions of data.

For example, if you’re using an AI model to generate a summary of a 300-page manual, chunking helps break the manual into smaller pieces for step-by-step analysis.

Challenges with Chunking

While chunking simplifies processing, it also introduces challenges, such as maintaining the flow of context between chunks. This is especially true when a topic spans multiple chunks. Developers often address this by including some overlap between chunks or by using advanced methods to “stitch” context together across chunks.

Chunking is a cornerstone of handling large-scale data in generative AI systems. It not only ensures efficient processing but also enables scalable analysis for complex tasks, such as summarizing, translating, or extracting insights from massive documents like research papers or legal contracts.