---
title: "PDF OCR server software — AI-powered cloud OCR | Nutrient Document Engine"
canonical_url: "https://www.nutrient.io/guides/document-engine/ocr/"
md_url: "https://www.nutrient.io/guides/document-engine/ocr.md"
last_updated: "2026-05-15T19:10:04.964Z"
description: "Unleash the power of optical character recognition (OCR) with our Document Engine guide. Learn how to transform your documents with ease. Elevate your workflow now!"
---

# PDF OCR server

Document Engine includes custom-built optical character recognition (OCR) technology to accurately recognize text and patterns, as well as generate searchable PDF/A files.

**Looking for more advanced OCR capabilities?**: Nutrient.NET SDK OCR offers additional powerful features, such as zonal OCR, key-value extraction, image preprocessing, searchable PDF/A generation with layout retention, orientation detection, confidence scoring, and more. It’s available as a separate SDK and can be used in conjunction with Document Engine.

[Learn more](https://www.nutrient.io/guides/dotnet/ocr/usage/image-to-searchable-pdf.md)

## Comparing OCR SDKs: Nutrient vs. Apryse

| Feature                                 | Document Engine OCR                               | Nutrient.NET SDK OCR  | Apryse OCR                                                                |
| --------------------------------------- | ------------------------------------------------- | ---------------------- | ------------------------------------------------------------------------- |
| Multi-language support                  | 120+ built-in languages                           | 30+ built-in languages | Six built-in languages with OCR module binary and 10 with IRIS OCR module |
| Searchable PDF creation                 | ✅                                                 | ✅                      | ✅                                                                         |
| OCR with exact bounding box coordinates | ❌                                                 | ✅                      | ✅                                                                         |
| Zone-based OCR/custom OCR regions       | ❌                                                 | ✅                      | ✅                                                                         |
| Key-value/table extraction              | ✅ (available through the [Data Extraction API](https://www.nutrient.io/api/data-extraction-api/)) | ✅                      | ❌                                                                         |
| Orientation detection                   | ❌                                                 | ✅                      | ✅                                                                         |
| Image preprocessing (deskew, etc.)      | ❌                                                 | ✅                      | ✅ (manual)                                                                |
| Performance and speed                   | ✅ Fast                                            | ✅ Fast                 | Depends on SDK setup (OCR module/IRIS module)                             |
| API access                              | Simple HTTP API                                   | Requires SDK setup     | Requires SDK setup                                                        |



### Real-world use cases

- **Invoice OCR** — Convert scanned invoices into searchable PDFs, or extract totals and vendor info using OCR.

- **Contract digitization** — Turn scanned contracts into searchable, selectable PDFs for legal archiving.

- **Form processing** — Use OCR to extract fields like names, dates, and signatures from scanned forms.

- **Multi-language document digitization** — OCR documents in multiple languages with full Unicode support.

## Which OCR SDK should I use?

| Need                                             | SDK to use                   |
| ------------------------------------------------ | ---------------------------- |
| Basic OCR from PDFs/images                       | Document Engine OCR          |
| Production-ready OCR solution without SDK setup  | Document Engine OCR          |
| OCR with form data, zones, orientation detection | Nutrient.NET SDK OCR        |
| Batch processing of scanned documents            | Either, depending on volume  |
| Need to preserve layout, tables                  | Prefer Nutrient.NET SDK OCR |

## Guides for OCR

---

**Usage**

Learn how to use the OCR API

[Read more](https://www.nutrient.io/guides/document-engine/ocr/usage.md)

---

**Language support**

Get a list of the languages supported by the OCR engine

[Read more](https://www.nutrient.io/guides/document-engine/ocr/language-support.md)

---

**Best practices**

Learn how to get the best results from OCR

[Read more](https://www.nutrient.io/guides/document-engine/ocr/best-practices.md)

**Call to Action**

Start your free trial for unlimited access and expert support.

[Learn More](https://www.nutrient.io/sdk/document-engine/getting-started.md)
---

## Related pages

- [Getting the best OCR accuracy](/guides/document-engine/ocr/best-practices.md)
- [Assuming Document Engine is running on `localhost:5000`.](/guides/document-engine/ocr/language-support.md)
- [How to use the OCR server](/guides/document-engine/ocr/usage.md)