What is Azure Translator document translation?

Learn about Azure Translator document translation for batch and single-file translation while preserving document structure and formatting.

What is Azure Translator document translation?

Document translation is a cloud-based machine translation feature of Azure Translator in Foundry Tools. Translate multiple and complex documents across all supported languages and dialects while preserving original document structure and data format. The Document translation API supports two translation processes:

• Asynchronous batch translation supports the processing of multiple documents and large files. The batch translation process requires an Azure Blob storage account with storage containers for your source and translated documents.

• Synchronous single file supports the processing of single file translations. The file translation process doesn’t require an Azure Blob storage account. The final response contains the translated document and is returned directly to the calling client.

Prerequisites

Asynchronous batch translation prerequisites

Before you start, you need:

• An active Azure subscription.
• A Translator resource. For resource creation and endpoint/key retrieval steps, see Use Document translation APIs programmatically.
• An Azure Blob Storage account with source and target containers. For setup guidance, see Create Azure Blob Storage containers.
• A way to authorize access to your storage URLs:
  • Shared access signature (SAS) tokens, or
  • Managed identities for Document translation.

Synchronous translation prerequisites

Before you start, you need:

• An active Azure subscription.
• A Translator resource with a custom domain endpoint. For setup and endpoint/key retrieval, see Use Document translation APIs programmatically.

Store subscription keys in a secure location such as Azure Key Vault, and avoid putting keys in source control.

Key features

Asynchronous (batch)

Feature	Description
Translate large files	Translate whole documents asynchronously.
Translate numerous files	Translate multiple files across all supported languages and dialects while preserving document structure and data format.
Translate image file formats 🆕	• Translate text within an image while maintaining the original design and layout. • Supported formats: .jpeg, .png, .bmp, .webp • Pricing: Calculated on a per-image basis. For more information, see Pricing.
Translate image text in Word documents (.docx) and PowerPoint files (.pptx) 🆕.	This feature is available with the batch document translation API for .docx and .pptx file formats.
Preserve source file presentation	Translate files while preserving the original layout and format.
Apply custom translation	Translate documents using general and custom translation models.
Apply custom glossaries	Translate documents using custom glossaries.
Automatically detect document language	Let the Document translation service determine the language of the document.
Translate documents with content in multiple languages	Use the autodetect feature to translate documents with content in multiple languages into your target language.

Synchronous

Feature	Description
Translate single-page files	The synchronous request accepts only a single document as input.
Preserve source file presentation	Translate files while preserving the original layout and format.
Apply custom translation	Translate documents using general and custom translation models.
Apply custom glossaries	Translate documents using custom glossaries. For guidance, see Use glossaries with Document translation.
Single language translation	Translate to and from one supported language.
Automatically detect document language	Let the Document translation service determine the language of the document.

How document translation works

Document translation supports two workflows. Choose the approach that matches your scenario.

Asynchronous (batch)

1. Upload source documents to your source container.
2. Submit a batch translation request.
3. Monitor job and document status.
4. Download translated documents from your target container.

For detailed request/response flows, see the Document translation REST API reference guide.

Synchronous

1. Send a request that includes one document (and an optional glossary).
2. Receive the translated document in the response.

For request details and examples, see Synchronous document translation.

Development options

Add document translation to your projects and applications using the following development options.

Foundry portal currently supports synchronous (single-file) document translation only. Use the REST API or client libraries for asynchronous batch document translation.

Asynchronous (batch)

Use asynchronous workflows to translate multiple documents and large files.

Development option	Description
REST API	The REST API is a language agnostic interface that enables you to create HTTP requests and authorization headers to translate documents.
Client libraries (SDKs)	The client-library (SDKs) are language-specific classes, objects, methods, and code that you can quickly use by adding a reference in your project. Currently Document translation has programming language support for C#/.NET and Python.

Synchronous

Use synchronous document translation to translate a single file and return the translated file in the response.

Development option	Description
Foundry portal (classic)	Try synchronous document translation in the Translator playground. In the classic portal, upload your own document and translate it end-to-end. To open the Translator playground, go to Foundry portal, ensure new Foundry is not selected, then select Playgrounds > Translator.
Foundry portal (new)	The new Foundry portal uses a sample document and translates only into a predefined set of languages. Doesn’t support customer-provided documents. For more information, see What is Microsoft Foundry?.
REST API	Integrate synchronous document translation into your applications by using the REST API.
Client libraries (SDKs)	Integrate translation capabilities into your applications by using the client libraries (SDKs).
Docker container	• To use the Translator container, complete and submit the Gated Services application online request form for approval to access the container. • The Translator container image supports limited features compared to cloud offerings. For more information, see Container: Translate Documents.

Supported document and glossary formats

The following tables list the document and glossary file formats supported by each translation method.

Asynchronous (batch)

Batch document supported formats

The Get supported document formats method returns a list of document formats supported by the Document translation service. The list includes common file extensions and content types.

File type	File extension	Description
Adobe PDF	pdf	Portable document file format. Document translation uses optical character recognition (OCR) technology to extract and translate text in scanned PDF document while retaining the original layout.
Comma-Separated Values	csv	A comma-delimited raw-data file used by spreadsheet programs.
HTML	html, htm	Hyper Text Markup Language.
Image (2025-12-01-preview)	.jpeg, .png, .bmp, .webp	Files that store digital image data.
OpenDocument Presentation	odp	An open-source presentation file.
OpenDocument Spreadsheet	ods	An open-source spreadsheet file.
OpenDocument Text	odt	An open-source text document file.
Markdown	markdown, mdown, mkdn, md, mkd, mdwn, mdtxt, mdtext, rmd	A lightweight markup language for creating formatted text.
M​HTML	mhtml, mht	A web page archive format used to combine HTML code and its companion resources.
Microsoft Excel	xls, xlsx	A spreadsheet file for data analysis and documentation.
Microsoft Outlook	msg	An email message created or saved within Microsoft Outlook. Unicode-format .msg files only. ANSI-format .msg files are not supported.
Microsoft PowerPoint	ppt, pptx	A presentation file used to display content in a slideshow format.
Microsoft Word	doc, docx	A text document file.
Rich text format	rtf	A text document containing formatting.
Tab separated values/TAB	tsv/tab	A tab-delimited raw-data file used by spreadsheet programs.
Text	txt	An unformatted text document.
XLIFF	xlf	A parallel document format used in translation and localization.

Batch Legacy file types

Source file types are preserved during the document translation with the following exceptions:

Source file extension	Translated file extension
.doc, .odt, .rtf,	.docx
.xls, .ods	.xlsx
.ppt, .odp	.pptx

Batch glossary supported formats

Document translation supports the following glossary file types:

File type	File extension	Description
Comma-Separated Values	csv	A comma-delimited raw-data file used by spreadsheet programs.
XLIFF	xlf	A parallel document format used in translation and localization.
Tab-Separated Values/TAB	tsv, tab	A tab-delimited raw-data file used by spreadsheet programs.

Synchronous

Synchronous document supported formats

File type	File extension	Content type	Description
Plain Text	.txt	text/plain	An unformatted text document.
Tab Separated Values	.tsv .tab	text/tab-separated-values	A text file format that uses tabs to separate values and newlines to separate records.
Comma Separated Values	.csv	text/csv	A text file format that uses commas as a delimiter between values.
HyperText Markup Language	.html .htm	text/html	HTML is a standard markup language used to structure web pages and content.
M​HTML	.mhtml .mht	message/rfc822 application/x-mimearchive multipart/related	A web page archive file format.
Microsoft PowerPoint	.pptx	application/vnd.openxmlformats-officedocument.presentationml.presentation	An XML-based file format used for PowerPoint slideshow presentations.
Microsoft Excel	.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet	An XML-based file format used for Excel spreadsheets.
Microsoft Word	.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document	An XML-based file format used for Word documents.
Microsoft Outlook	.msg	application/vnd.ms-outlook	A file format used for stored Outlook mail message objects.
XLIFF	.xlf	application/xliff+xml	A standardized XML-based file format widely used in translation and localization software processing.

Synchronous glossary supported formats

Document translation supports the following glossary file types:

File type	File extension	Description
Comma-Separated Values	csv	A comma-delimited raw-data file used by spreadsheet programs.
XLIFF	xlf	An XML-based format designed to standardize how data is passed during the localization process.
Tab-Separated Values	tsv, tab	A tab-delimited raw-data file used by spreadsheet programs.

Document translation request limits

For detailed information about Translator request limits, see Document translation request limits.

Document translation data residency

Document translation data residency depends on the Azure region where your Translator resource was created:

✔️ Feature: Document translation
✔️ Service endpoint: Custom domain: https://<your-resource-name>.cognitiveservices.azure.com

Resource created region	Request processing data center
Global	Closest available data center.
Americas	East US 2 • West US 2
Asia Pacific	Japan East • Southeast Asia
Europe (except Switzerland)	France Central • West Europe
Switzerland	Switzerland North • Switzerland West

Troubleshooting

Use the following checks to diagnose common issues.

Batch translation

• If translated files don’t appear in the target container, check job status using Get status for a specific translation job and document status using Get status for a specific document.
• If the service can’t read from or write to your storage containers, confirm storage authorization:
  • If you use SAS tokens, see Create shared access signature (SAS) tokens for storage containers and blobs.
  • If you use managed identities, see Create and use managed identities.
• If a job fails due to unsupported inputs, confirm the format using Get supported document formats.

Synchronous translation

• If the request fails due to invalid parameters or unsupported file types, review the required parameters and supported formats in Synchronous document translation.
• If you hit rate limits, see Document translation request limits.

Related content

• Document translation quickstart
• Use Document translation APIs programmatically
• Use glossaries with Document translation
• Document translation REST API reference
• Translator language support