Cloud Translation Blog | Tips to improve translation workflow from Pairaphrase

Best Way to Translate a Scanned Document PDF [2025]

Written by Valerie Julien | Sep 22, 2025 9:45:00 PM

Translating scanned documents is notoriously challenging. Ultimately, the best way to translate scanned PDF files for your organization is to use an online scanned document translator that has the right technology in place to help prevent or address PDF language translation problems

While it’s an investment, the delays caused by bottlenecks in the translation process will ultimately cost you more time and money by impacting your multilingual communication milestones.

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Why take our advice on translating scanned PDFs?

Our professional experience with scanned PDF translation

As language industry veterans who have been translating scanned documents for decades, we’ve solved PDF translation challenges for organizations that were experiencing the same core problems again and again. We’ve even gone so far as to build our own translation software, Pairaphrase, to build better workflows to translate scanned PDFs efficiently.

Overview: why it’s so hard to find the best way to translate scanned PDFs

Firstly, there aren’t many scanned document translation software programs that will properly translate a scanned PDF for you (a document that was scanned into a computer). They exist, but there aren’t many. Secondly, many scanned PDF translator tools online won’t translate large PDF files.

Finally, most scanned PDF translator tools are:

  • not optimized for scanned documents
  • not equipped to preserve formatting
  • not built to support a wide variety of file types

But don’t worry– we’ll tell you exactly how to translate image-based documents step-by-step in this article.

Because fortunately, modern AI PDF translator tools (like Pairaphrase) now offer smarter, more secure ways to translate scanned documents without the pain of traditional methods.

Want to translate a scanned document ASAP? Check out the AI scanned PDF translator Pairaphrase.

The role of CAT tools in PDF translation

Using a Computer-Assisted Translation (CAT) tool is essential when working with complex file formats like scanned PDFs. The right CAT tool will not only improve translation accuracy but also help retain formatting, achieve consistency in translations, and enhance efficiency.

Proof is in the data

According to a study led by ProZ, 88% of full-time professional translators use at least one CAT tool in their daily work. Furthermore, 76% of them utilize more than one CAT tool to manage different tasks and improve productivity. 

Types of tools that offer PDF translation features  

CAT tools are the platforms that most commonly offer helpful PDF translation features like Optical Character Resolution (OCR), PDF conversion settings and Translation Memory

Some go even further by integrating AI for translating scanned documents. For example, a custom-trained translator GPT to assist with layout-related issues like text length expansion after translation, as well as other translation activities.

The ChatGPT translation assistant inside the Pairaphrase platform

Factors to consider when translating scanned documents

There are several critical factors involved in figuring out the best way to translate a scanned document PDF. Here’s what to consider:

Readable text

Before you invest in a top-notch translation system, you must figure out if your PDF text is “readable” by the platform so you can get the highest quality translation for scanned documents.

Formatting preservation

You’ll also want to preserve the formatting for your translated file (as much as possible) so that you don’t need to reformat an entire document. This includes retaining font properties, image placement, spacing, line breaks, paragraph breaks and more.

Handling complex layouts 

Scanned PDFs often include complex layouts, such as tables, graphics, and embedded images with text. You’ll want to become familiar with the level of complexity in your PDF structure.

Resolution of the scanned document 

The quality of the original scanned document plays a huge role in translation accuracy. Low-resolution scans can result in OCR errors, which in turn lead to incorrect translations.

Read below to learn the best approach to translating a scanned PDF to solve these issues as best as possible. We’ll also recommend the best scanned PDF translator online.

How to translate a scanned document PDF for quality & time-savings

1. Determine the type of scanned document you’re translating

The first step toward finding the best method for translating a scanned document PDF accurately (and while retaining formatting) is to determine the type of PDF you’re translating.

Yes, there are two types. And yes, it does matter!

Two main types of PDFs:

  • Digital PDFs (text-based)
  • Scanned PDFs (image-based)

The type of PDF you have will affect your translation quality. Knowing the type of PDF you have will help you ensure that you take the right steps before translation to ensure the most accurate and well-formatted translation possible.

This saves you time and money in the long run.

How to check your PDF type

A quick way to check if your PDF is image-based (scanned) or text-based (digital) is by clicking and holding your mouse or trackpad while dragging it over the text.

→ If you see a text cursor appear and you’re able to highlight the text, this indicates that your document is a digital PDF. In this case, there are no more preparation steps to take before running it through translation software (skip to #3 at the bottom of this post).

→ If you drag your mouse or trackpad and it shows a cross, it’s a scanned PDF. In this case, continue reading from here to learn the best way to translate a scanned document PDF.

2. Apply OCR to the scanned PDF

Scanned documents in image format are never going to translate as accurately as other types of documents will. This is because when you scan a document to turn it into a PDF, it’s usually going to scan in as a flat image. In this case, the text is unreadable as is.

The best way to translate a scanned document PDF accurately and to retain formatting is by using Optical Character Recognition (OCR). OCR will recognize characters in your document and convert them to digital text.

TIP: Streamline this step by using a scanned document translator with OCR built-in, such as Pairaphrase.

3. Choose the right PDF conversion mode

Once your scanned document has been converted with OCR (not a separate step when you use Pairaphrase since it’s automated during translation), the next step is to decide how you want the PDF content to be structured for translation. 

 

While “PDF conversion settings” are not a common offering in translation software, Pairaphrase gives you two options:

  • Retain Flowing Text (Default): Converts your PDF into editable, linear text blocks. This makes the content easier to segment, reflow, and post-edit—ideal when translation quality and speed are your top priorities, and the layout doesn’t need to look exactly like the original.

  • Retain Page Layout: Preserves the original formatting, spacing, and design elements of your PDF. While this option is less editable, it’s the best choice when maintaining the look and feel of the original document is critical (such as brochures, certificates, or forms).

TIP: You can set your preferred mode directly in your Pairaphrase profile under “PDF Conversion Settings”. Selecting the right option will help you balance accuracy, editability, and visual consistency based on your project’s needs.

4. Translate your scanned PDF document

Next, upload your scanned PDF to your translation tool to get a quality translation. As we mentioned earlier, the best way to translate a scanned document is to use translation software that’s optimized for scanned documents. Furthermore, use a tool that supports various file types, AI translation features, streamlined workflows, security and compliance. 

Enterprise-grade PF translation tools like Pairaphrase:

  • detect and extract text via OCR
  • translate with AI (using engines like ChatGPT, DeepL, and Google Translate)
  • retain layout, font size, tables, and images
  • secure your data using enterprise security standards

Note: You might have to spend a little bit of time reformatting the translated scanned document.  But by this point, you should have already saved yourself hours by using a translation tool optimized for PDFs.

Top 3 tips for translating scanned document PDFs

1. Remove all text obstructions before uploading your document to a PDF translator 

With PDF translation, it’s common to receive sub-par results if your file contains any of the following obstructions that make it difficult for OCR to read the characters in your file:

  • Stamps that cover text
  • Watermarks that cover text
  • Handwriting that covers text
  • Drastic creasing that obstructs your text
  • Text that shows through from the other side
  • Another document layered on top of it
  • Text within embedded images
  • Very low contrast between the background & text
  • Graphics on dark backgrounds
  • Ornate / heavily scripted text
  • Handwritten text (OCR technology cannot yet accurately recognize it)
  • Text cut off mid-sentence

2. Improve the PDF resolution before translating

Translating PDF documents becomes a lot easier when you improve the quality of the resolution prior to uploading them to Machine Translation software. 

This makes it easier for the OCR engine in your translation software to read the text before it’s translated. OCR is what enables the language translation tool to recognize the characters in an image or scanned PDF. 

You might even be able to bypass some of the text obstructions listed in Tip #1 if your PDF has a resolution of 300 DPI or higher.

How to find out PDF resolution

To find out if your document is high resolution to begin with, check the file size in your finder window / file directory. If it’s high resolution, each page should be approximately 1MB or higher (this isn’t always the case–but most often it is).

How to improve PDF resolution

If you have a hard copy, rescan it into your computer at a resolution of 300 DPI or higher. You can achieve this by opening your scanner’s settings on your computer before you scan the hard copy and changing the resolution manually.

3. Play around with file formats

When it comes to successful PDF translation, sometimes converting a PDF to JPG or DOC can yield better results. 

You might translate the PDF and not be satisfied with it, and then convert and translate a JPEG and see improvements. Some documents will translate better as a DOCX and others will translate better as PDF––try playing around with it.

Note: No translation software will successfully translate every PDF file. Your translation results will vary from file to file and language to language. Some PDF files are best translated by a human. 

Need help converting and translating scanned documents or PDFs? Read our guide to troubleshooting common PDF translation problems.

Recommended online scanned document translator 

To achieve the best scanned PDF translation, use Pairaphrase. It’s the AI Translation Management System for teams that value faster, smarter and safer translation. Plus, it will translate your scanned document text in a way that gives you higher-quality results compared to tools that are not optimized for scanned PDFs.

The video below explains how Pairaphrase will actually OCR your files for you. Watch the video to get important pointers for receiving the highest quality scanned document translation results possible. Pay close attention, as this video will save you a lot of time and head scratching.

Note: It’s important to understand that retaining the formatting of a scanned PDF is very difficult in comparison to retaining the formatting of an original digital PDF (the one that ended up getting printed).

How to translate a scanned PDF directly with Pairaphrase

Translating a scanned PDF can be challenging, but Pairaphrase simplifies the process through its integrated Optical Character Recognition (OCR) and AI-powered translation.

Here’s a step-by-step guide to translating scanned documents directly with Pairaphrase:

1. Upload your scanned PDF 

Start by checking your PDF conversion settings in your Pairaphrase account. Then, upload your scanned PDF file to Pairaphrase. If your PDF is image-based (as most scanned PDFs are), don’t fret! Pairaphrase will automatically apply its built-in OCR technology to recognize the characters and convert them into editable text.

NOTE: If your PDF does not have the correct language settings in place, the OCR outcome will not be successful. 

2. Review and edit

After the initial translation, you’ll receive a draft that can be reviewed and post-edited. Pairaphrase offers tools like Translation Memory, which helps you store and reuse translated phrases. What’s more, it uses automatic formatting to reduce the manual work on the translated document.

You can also invite a colleague to view or collaboratively edit the file within Pairaphrase. What’s  more, you can use Pairaphrase’s ChatGPT integration to assist with translation post-editing and review. 

3. Export the translated file 

When you’re satisfied with the translation, export the file by clicking “Download” and selecting the “Download Translation” menu item. 

If you’re translating a Google Drive PDF, Pairaphrase directly translates and syncs it for you, eliminating the need to download the Google PDF file and re-upload it to Google Drive. 

Pairaphrase also keeps most of the original formatting intact, saving you time and effort in reformatting the translated document.

4. Done! 

Pairaphrase’s OCR and translation capabilities work seamlessly, enabling you and your team to quickly and easily translate scanned PDFs without losing critical information.

What makes Pairaphrase so great?

  • Easy-to-use online scanned document translation software
  • Built specifically for organizations & enterprises
  • Helps your team manage translations and collaborate with colleagues across the world
  • Learns your words and phrases so that you never need to translate the same text segment twice
  • Saves you a significant amount of time and money in the long run
  • Encodes your files to retain as much of the formatting as possible
  • Reduces the instances of displaced images, lost font properties or erroneous spacing
  • Keeps as much of your formatting as possible–more than other software systems do
  • Secures your data so you don’t need to worry about sending your data through an unsecured tool
  • Can output the translated text in a Microsoft Word document so that users have an editable file to work with

With all Pairaphrase plans, your files and data are encrypted. Not only that, but we never share, index or publish your data. It remains 100% confidential.

Key Features to Look for in a Scanned PDF Translator

If you’re looking for the best AI-powered PDF translator for your organization, choose one that does more than just convert files. The right platform should assist your entire translation workflow — from scanned documents to multimedia content — while maintaining accuracy, security, and flexibility.

Here are the essential features to look for:

  • Built-in OCR for scanned PDFs to extract text accurately
  • Formatting preservation to retain the majority of layout, fonts, and images
  • Support for 25+ file formats, including audio and video files like .mp3, .mp4, .wav, and WebVTT
  • Integration with ChatGPT for in-platform translation prompts and refinement
  • Voice translation with both speech-to-speech and speech-to-text capabilities
  • Translator GPT (like PairaphraseGPT) for AI-enhanced translation suggestions and edits
  • Multilingual content creation tools, like Pairaphrase’s AI Sandbox for generating content in multiple languages
  • Translation Memory that stores repeated phrases to save time
  • Selectable translation engines, including Google, DeepL, Microsoft Translator, ChatGPT, and PairaphraseGPT
  • Powered by Agentic AI and Generative AI, built for enterprise scalability and control

These features make tools like Pairaphrase more than just a scanned document translator. It’s an AI-driven platform that supports your end-to-end translation process—across PDFs, audio, video, and dynamic content creation.

If you’re looking for the best AI PDF translator for your enterprise, read our suggested features here

Pairaphrase tips

When you use Pairaphrase as your scanned PDF translator, we strongly recommend the following tips to get high-quality translations: 

  • Follow the prep steps in the video

Preparing your file as shown in the tutorial helps preserve formatting and improves translation quality.

No Machine Translation is perfect on its own. Reviewing and editing your translation ensures greater accuracy and consistency—especially for formal documents.

Keep your translations consistent by defining and applying key terms across documents.

  • Use advanced AI features

Tools like PairaphraseGPT and the AI Sandbox can refine translations, generate multilingual content, and adjust tone or length to fit your needs.

  • Translate audio and voice content

Use the built-in voice translator for projects involving speech-to-text or speech-to-speech translation.

Note: Translations generated by Machine Translation can never be as high-quality on its own as translations that are machine translated and then edited by a human translator. This will also enable you to benefit from our Translation Memory technology, which stores your translated text so you only have to edit once.

How to translate scanned documents with ChatGPT

If you prefer to use ChatGPT for your translation needs, this is important to note: ChatGPT cannot directly translate a scanned PDF into another language because it does not have built-in capabilities for processing or extracting text from images. However, it is now possible to use ChatGPT as a translation engine within Pairaphrase (the only system that offers this!), which eliminates this issue. If you don't use Pairaphrase, follow the instructions below.

Scanned PDFs are typically image-based, and ChatGPT requires text input to provide translations. However, you can still translate a scanned PDF using ChatGPT by following these 3 steps:

1. Extract your scanned PDF’s text

Use OCR (Optical Character Recognition) software, like Adobe Acrobat or Google Drive, to extract the text from the scanned PDF. This step converts the images of text into editable text format.

2. Copy the extracted text

Once the text is extracted, you can copy and paste it into ChatGPT.

3. Translate the text using ChatGPT

Request a translation of the extracted text within ChatGPT. For a smoother and more efficient process, especially for complex documents, we recommended using dedicated translation tools or services that can handle OCR and translation in one integrated workflow, such as Pairaphrase.

Read our translator’s guide to the best ChatGPT prompts for high-quality translation.

How AI PDF translators improve translation of scanned documents

AI doesn’t just speed things up—it also improves the quality and usability of your translated PDFs. Here’s how:

  • Improved OCR accuracy: AI-enhanced OCR engines better detect characters in low-quality scans.

  • Formatting retention: AI can reconstruct tables, spacing, bullet lists, and font styles more effectively than older tools.

  • Smarter language handling: AI translation tools understand language context, reducing awkward phrasing.

  • Style control and refinement: Tools like PairaphraseGPT let you refine tone, simplify language, or adjust the output per audience.

  • Multilingual content creation: AI systems can even help generate original content in multiple languages.

In short, AI-powered PDF translators don’t just automate—they enhance.

How to use Pairaphrase’s OpenAI integration to access ChatGPT directly

Pairaphrase’s recent integration with OpenAI’s ChatGPT elevates the translation process by providing you direct access to advanced AI features within the platform. 

With the ChatGPT integration, you can prompt ChatGPT directly in Pairaphrase’s interface. This eliminates the need to switch between applications, streamlining your translation workflow. 

Can ChatGPT translate scanned documents and PDFs?

For those wondering if ChatGPT can translate scanned documents, Pairaphrase is currently the only option available to translate a scanned document with ChatGPT. It will automatically apply OCR to your scanned PDF upon upload, then allow you to generate translations while interacting with ChatGPT-4o within the same interface.

Simply use the OpenAI integration as a translation assistant within the platform, whether you need help generating alternative translations, refining the output, or reducing character count to match your document’s layout.

Go one step further with PairaphraseGPT

In addition to ChatGPT, Pairaphrase also includes PairaphraseGPT—a translator GPT trained specifically for translation. It offers smarter translation suggestions based on enterprise content, glossary terms, and formatting needs.

Together, these tools help you move beyond basic machine translation toward a more intelligent and adaptive approach to PDF and document translation.

Growing demand for translation of scanned documents

While translating scanned documents and PDFs is a critical need, Machine Translation technologies are expanding into various industries. 

According to a Global Market Insights industry report, the U.S. market for Machine Translation is expected to see significant growth in the next five years, particularly in sectors like healthcare, electronics, and eCommerce. If you’re in one of these industries, now is especially a great time to explore an effective solution for the long run. 

Solutions like Pairaphrase are at the forefront of meeting these industry demands by offering OCR-enabled translation for scanned PDFs, a feature that is becoming increasingly vital in sectors handling high volumes of multilingual documentation.

Level-up your scanned PDF translation process 

Want to get started with the best AI PDF translation tool for scanned documents? Try Pairaphrase. It’s the AI Translation Management System for teams that value smarter, faster and safer translation. 

Pairaphrase supports 140+ languages and 20,000+ language pairs. Use AI to translate a PDF into Spanish, English, German, French, Italian, Portuguese, Arabic, Hindi, Swedish, Dutch, Korean, Vietnamese, Japanese, Chinese, and more. Not to mention, Pairaphrase translates 25+ file types.

Just one translation with Pairaphrase can cover your annual subscription!

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