OCR Output Formats Compared: TXT, PDF, PDF/A, XML, JSON

Last Updated: 12 Jan, 2026

Optical Character Recognition (OCR) is no longer just about converting scanned pages into readable text. In today’s data-driven world, the OCR output format you choose can directly impact searchability, compliance, long-term preservation, automation, and integration with modern applications. From simple text extraction to structured, machine-readable data, each format serves a distinct purpose.

In this detailed guide, we’ll compare the most commonly used OCR output formats—TXT, PDF, PDF/A, XML, and JSON—to help you choose the right one for your workflow, whether you’re building an open-source OCR pipeline, an enterprise document system, or an AI-powered analytics platform.

What is OCR and Why Does Output Format Matter?

OCR converts images of text (scanned documents, photos, PDFs) into machine-encoded text. This process unlocks the ability to search, edit, and analyze previously static content. However, the raw text data must be structured and packaged into a usable format.

The output format determines:

• Accessibility: How easily can you read and search the content?
• Preservation: Does it maintain the original layout and visual integrity?
• Interoperability: Can other software and systems easily use the data?
• Editability: How simple is it to modify the extracted text?
• Metadata & Structure: Does it retain information like font, position, or logical hierarchy (headings, paragraphs)?

Choosing incorrectly can lead to lost formatting, difficult integrations, or documents unsuitable for legal archiving.

In-Depth Comparison of OCR Output Formats

1. TXT (Plain Text)

The simplest and most universal format. TXT files contain only the extracted character sequence with no styling, images, or layout data.

• What you get: Raw text. Line breaks and spacing are often based on the OCR engine’s best guess.

• Strengths:

  • Extremely Lightweight: Tiny file sizes.
  • Universally Compatible: Opens on any device with any text editor.
  • Excellent for Text Analysis: Ideal for data mining, natural language processing (NLP), or keyword indexing.
  • Fully Editable: Easy to copy, paste, and modify.

• Weaknesses:

• Loss of All Formatting: Fonts, bolding, columns, and page structure are lost.

• No Images: Embedded graphics or photographs are discarded.

• Poor Visual Representation: Bears little visual resemblance to the source document.

• Best For: Extracting pure textual content for analysis, simple search indexing, or when storage space is a primary concern. Not suitable for document archiving or formatted reports.

• SEO Note: Perfect for creating crawlable text content from scanned documents to be published on the web, as search engines can easily parse plain text.

2. PDF (Portable Document Format - Standard)

A PDF created by OCR (often called a “searchable PDF” or “PDF with text layer”) embeds the recognized text invisibly behind the original scanned image.

• What you get: A document that looks exactly like the original scan but allows you to select, search, and copy text.

• Strengths:

  • Preserves Original Layout & Look: Maintains fonts, columns, images, and graphics.
  • Searchable & Selectable: Combines visual fidelity with text functionality.
  • Widely Accepted: The global standard for document sharing.

• Weaknesses:

• Larger File Size: Contains both the image and text layer.

• Limited Structural Data: While searchable, it doesn’t inherently understand titles vs. paragraphs.

• Proprietary Editing: Requires specific tools (like Adobe Acrobat) for advanced text-layer edits.

• Best For: Sharing documents that need to look identical to the original while enabling text search. Common in legal, academic, and business correspondence.

• SEO Note: Search engines can crawl the text layer of a searchable PDF, improving the document’s findability for relevant queries.

3. PDF/A (PDF for Archiving)

A specialized ISO-standardized subset of PDF designed for long-term digital preservation. OCR output in PDF/A ensures the document will be readable and appear identical far into the future.

• What you get: A self-contained, searchable PDF with all fonts embedded and without elements prone to obsolescence (like JavaScript or external links).

• Strengths:

• Long-Term Integrity: Guarantees the document will display the same way decades from now.

• Compliant: Meets strict legal and regulatory archiving requirements (e.g., in government, libraries, healthcare).

• Contains All Necessary Metadata: Includes identification and preservation details.

• Weaknesses:

• Even Larger File Sizes: Due to embedded fonts and restrictions.

• Less Flexible: Cannot contain audio, video, or executable content.

• Overkill for Everyday Use: The strictness is unnecessary for temporary or informal documents.

• Best For: Legal records, historical archives, medical records, and any document mandated for permanent, compliant preservation.

• SEO Note: While archiving is its primary goal, the text remains crawlable, ensuring archived public documents remain discoverable.

4. XML (Extensible Markup Language)

XML provides a structured, hierarchical representation of the OCR output. It uses custom tags to define different elements of the document.

• What you get: Not just text, but text wrapped in descriptive tags (e.g., , , ).

• Strengths:

• Rich Structure: Captures hierarchy, logical sections, and metadata.

• Platform & Software Independent: Pure text-based structure that integrates seamlessly with databases and content management systems (CMS).

• Ideal for Data Repurposing: Content can be easily transformed and published to various formats (web, print, e-books) using stylesheets (XSLT).

• *Weaknesses:

• Complexity: Not human-readable at a glance; requires knowledge of the tag set.

• No Visual Layout: While structure is preserved, the precise visual rendering is not.

• Requires Processing: Needs parsing by another application to be presented in a user-friendly way.

• Best For: Publishing workflows, digital libraries, and content destined for multi-channel publication. It’s the backbone for complex document management systems.

• SEO Note: Highly valuable for SEO when publishing structured content online. The clean, tagged data helps search engines understand content hierarchy and context.

5. JSON (JavaScript Object Notation)

A lightweight, hierarchical data-interchange format that is particularly easy for humans to read and for machines to parse. In OCR, JSON often represents structured text data and its bounding box coordinates.

• What you get: A structured collection of key-value pairs and arrays, often detailing text content, confidence scores, and the precise position (coordinates) of each word or block on the page.

• Strengths:

• Excellent for Developers & APIs: The de facto standard for web applications and RESTful APIs.

• Machine-Readable & Human-Readable: Easier to interpret at a glance than XML for many developers.

• Rich Data: Can include OCR confidence levels, font data, and spatial relationships.

• Compact: Less verbose than XML, leading to smaller file sizes for equivalent data.

• Weaknesses:

• No Visual Output: Purely a data format.

• Requires Programming Knowledge: To be useful, it needs to be processed by custom code or an application.

• Not for Direct Viewing: End-users cannot open a JSON file and “read” the document.

• Best For: Web and mobile applications, feeding data into databases, and any scenario where OCR data needs to be consumed by another software program (e.g., automated form processing, data extraction pipelines).

• SEO Note: While not used for direct publishing, JSON is crucial for powering dynamic web content and structured data (like JSON-LD), which are key to modern SEO.

Side-by-Side Comparison Table

How to Choose the Right OCR Output Format

Ask these questions to guide your decision:

1. What is the end goal?

• Permanent Legal Archive? -> PDF/A
• Share a faithful, searchable copy? -> Searchable PDF
• Feed text into an app or database? -> JSON or XML
• Perform text analysis or data mining? -> TXT
• Republish content in multiple formats? -> XML

2. Who or what is the consumer?

• Humans (e.g., lawyers, researchers): PDF or PDF/A.
• Another Software System (e.g., a web app): JSON or XML.
• A Search Engine Index: TXT or the text layer within a PDF.

3. Is visual integrity non-negotiable?

• If YES: PDF or PDF/A.
• If NO: Consider TXT, XML, or JSON.

4. Do you need to preserve document structure (headings, lists)?

• If YES: XML is the strongest choice.
• If NO: TXT or basic PDF may suffice.

Pro Tip: Many advanced OCR solutions allow you to output multiple formats simultaneously. You might generate a PDF/A for archiving, an XML for your content repository, and a TXT for your search index—all from a single scan.

Conclusion

There is no single “best” OCR output format. The right choice is a strategic decision that hinges on your specific use case:

• TXT is the nimble workhorse for raw text.
• PDF is the universal standard for faithful, searchable copies.
• PDF/A is the gold standard for future-proof archiving.
• XML is the powerful engine for structured publishing.
• JSON is the agile connector for modern applications.

By understanding the capabilities and trade‑offs of each format, you can design OCR workflows that are not only efficient but also produce outputs perfectly suited for their intended purpose, ensuring your digitized content remains accessible, usable, and valuable for years to come.

FAQ

Q1: Which OCR format is best for long‑term digital archiving?

A: PDF/A is specifically designed for long‑term preservation and is the best choice for legal or compliance archiving.

Q2: Can search engines read text extracted by OCR?

A: Yes, search engines can crawl the text layer in searchable PDFs and plain TXT files, making them excellent for SEO.

Q3: What is the main difference between a standard PDF and a PDF/A from OCR?

A: A standard PDF prioritizes visual fidelity, while a PDF/A is a self‑contained, stricter format guaranteed for future readability and compliance.

Q4: I need to feed OCR data into a mobile app—which format should I use?

A: Use JSON, as it is the standard, lightweight format for data interchange in web and mobile applications.

Q5: Which format preserves the original document’s layout and images?

A: Both standard searchable PDF and PDF/A formats preserve the original visual layout, fonts, and embedded images.

See Also

• PDF/A-3 - The Hybrid Monster? Embedding Original Data Inside Your OCR
• Understanding OCR File Formats - HOCR vs ALTO vs PDF/A Explained
• What is the Difference Between PDF and FDF?
• What is FDF Used For? Understanding the Purpose of Forms Data Format
• PDF vs Word: Which One Should You Use and When?