Immersive translation

What is immersive translation?

Immersive Translation is a bilingual translation extension that keeps the original text on the webpage while displaying the translation.

It also supports video subtitles, input fields, mouse hover effects, as well as the translation of PDFs, e-books, and various other document types.

Main functions

• Bilingual translation of the webpage text.
• Hover and scroll for word translation.
• Quick translation for web form input fields.
• Bilingual subtitles for online videos.
• Translation of PDF and scanned documents.
• Creation of bilingual ePub e-books.
• Translation of files in Word, Markdown, TXT, and other formats.
• Translation of SRT, ASS, and VTT subtitles.
• Switching between multiple translation engines and using custom API keys.

Bilingual website translation

The extension identifies the main content of a webpage and inserts the corresponding translation near the original paragraphs.

This layout is suitable for reading news, technical documents, forums, and materials in foreign languages.

• Keeping the original text allows for easy verification at any time.
• It is possible to adjust the translation style and the range of display.
• It supports automatic translation for specified websites at all times.
• Code, formulas, and unnecessary sections can be skipped.
• Dynamic web pages and pages with complex scripts may require a while to load.

Hover and word-by-word translation

Users can move the mouse over a paragraph and then use a shortcut key to display the translation of the current content.

• Suitable for translating only a small number of new words or paragraphs.
• Avoid excessive consumption resulting from translating entire pages.
• It can be used for buttons, comments, and short texts.
• Some text on canvases or images cannot be selected directly.
• Shortcut keys can be adjusted in the advanced settings.

Input field translation

Translation in the input field can convert the content that the user is editing into the target language.

• Used in search boxes and email editors.
• Assists in posting content in foreign languages on social media platforms.
• Suitable for two-language communication with chatbots.
• Before sending, check the tone, addressing, and sensitive information.
• Password fields and protected input areas are not treated as ordinary text.

Bilingual subtitles for videos

Immersive translation supports subtitle translation for various popular video websites, displaying subtitles in both languages.

• Suitable for course, interview, and lecture videos.
• The video itself needs to provide or be able to generate subtitles.
• The quality of subtitles is influenced by speech recognition and the timeline.
• Names, terms, and numbers still need to be verified against the audio.
• The available capabilities of different websites may change as their pages are updated.

Document translation

The official documentation page shows formats such as PDF, ePub, HTML, TXT, JSON, DOCX, and Markdown.

Subtitle files also support common formats such as SRT, ASS, and VTT.

• Plain documents are suitable for files with a relatively simple structure.
• PDF Pro is used for scanned documents, formulas, and complex layouts.
• BabelDOC emphasizes preserving the original layout and bilingual formatting.
• Check the tables, footnotes, and page order before exporting.
• Files that are password-protected or damaged may not be able to be parsed.

Free PDF version, PDF Pro, and BabelDOC

BabelDOC quota

The official quick-start guide states that free users can process 1,000 pages per month, while Pro members can process 10,000 pages per month.

• For free users, the limit on the number of pages per upload is determined by the number of pages uploaded in real time.
• Pro can handle larger individual documents.
• The number of queue files and the concurrency rules may be adjusted.
• The actual processing time for complex PDFs is significantly higher than that for ordinary text.
• Enabling OCR will increase the parsing time.

Supported languages and translation engines

The product supports over 100 languages and integrates more than 20 major translation engines.

• Traditional translation services such as DeepL and Google.
• AI models such as DeepSeek, OpenAI, and Claude.
• Gemini and other optional services.
• Some engines require members or users to provide their own keys.
• Different engines offer varying languages, qualities, and costs.

How to choose a translation engine

• For regular web use, it is preferable to choose services with fast speeds.
• Academic papers choose models with stronger context understanding capabilities.
• Professional documents use consistent translations in conjunction with a glossary.
• Sensitive data requires priority assessment regarding the data flow of custom APIs.
• For long texts, test the quality and token consumption on a small scale first.
• The key content must be reviewed manually in the original language at least once.

Tutorial for Immersive Translation

1. Install the corresponding browser or mobile version through official channels.
2. Fix the expansion icon and open the settings page.
3. Select the source language, target language, and translation engine.
4. Log in to your account or configure a custom API as needed.
5. Open a foreign-language webpage and click to translate the current page.
6. Adjust bilingual display, font size, and translation style.
7. Set up automatic translation rules for frequently used websites.
8. Use the hover or word-scrolling feature to work on specific content.
9. Play foreign language videos with bilingual subtitles enabled.
10. Before uploading a document, check its format, copyright, and privacy aspects.
11. After exporting, check the layout, terminology, and numbers.
12. Regularly check the device status, quota, and renewal status.

Prices for the free version, Pro, and Max

As of August 30, 2026, the official membership agreement shows the following subscription prices.

Membership is renewed automatically; the list of models, prices, and quotas may change. Please refer to the settlement page before making a purchase.

How to choose between Pro and Max

• The free version is suitable for basic web pages and light document reading.
• Pro is suitable for users who frequently read papers, documents, and videos.
• Max is suitable for power users who require advanced models with high computational demands.
• The top-tier model quota is only explicitly provided in the Max plan.
• Test the monthly payment feature and the quality of the engine before opting for an annual payment.
• Users who use their own APIs also have to cover the costs associated with third-party models.

How to understand the token quota?

A token is the unit used by the model to process text; it is not equivalent to a fixed number of characters or a fixed number of web pages.

• Both the original text and the generated translation can count towards the consumption.
• The conversion ratio between tokens in Chinese and English is different.
• Long contexts and complex prompts increase consumption.
• The measurement rules for different models may vary.
• The remaining monthly quota and renewal time are specified on the account page.

Limit on the number of devices

According to the FAQ on the pricing page, each account can use up to 8 browser devices at the same time.

• The device that logs in first after exceeding the limit will be disconnected.
• A browser that has been reinstalled or configured differently may be considered a new device.
• Do not have multiple people share the same membership account.
• Before selling the equipment, you should log out of the account and delete any additional data.

Automatic renewal and refunds

The monthly and annual plans for Pro and Max are automatically renewed in accordance with the agreement.

A reason must be provided for the refund; requests made after the deadline or when a large amount of the credit has already been used may be rejected.

Privacy and data flow

The translated content of web pages is sent to the translation engine selected by the user; the platform primarily collects anonymous usage statistics.

Files, images, and BabelDOC require processing of content uploaded by users; sensitive information should be used with caution.

• BabelDOC files are retained only temporarily, for as long as it is necessary to complete the service.
• After the service is completed, the submitted content and results are deleted in accordance with the policies.
• The member’s PDF may be sent in an encrypted format to Mathpix for analysis.
• Custom API requests can be sent directly to the selected service provider.
• Accounts, devices, IPs, and error logs may be processed.
• The complete payment card details are processed by third-party payment services.

Precautions for cross-border storage

According to the privacy policy, personal information may be stored or processed in South Korea, and cross-border data transfers may occur.

• Before uploading corporate documents, internal compliance requirements should be checked.
• Contracts, documents, and customer information are first anonymized.
• Confirm the region where the selected translation engine is located and its privacy policy.
• When there are requirements regarding where the data is stored, custom services should be used first.
• Highly sensitive files should not rely solely on ordinary online tools.

Open-source status

The official GitHub repository clearly states that the current immersive translation tool is not open-source software.

The main repository is used solely for releasing Release versions and collecting issues; it does not contain the current product’s source code.

• The old version of the project had its source code made public, but it was archived in 2023.
• The old version of the license does not represent the authorization method for the current version.
• The public ImmersiveL is an independent model framework.
• The Zotero BabelDOC plugin has its own open-source license.
• The open-sourcing of related projects does not mean that the main extension is fully open-sourced.

Custom API key

Users can configure their own translation service keys based on the available functionality.

• Keys can only be created from the provider’s official console.
• Do not take screenshots of the key or share it with others.
• Set balance limits, thresholds, and alerts for abnormal calls.
• Different service providers charge separate fees for the models.
• The key is revoked and regenerated immediately upon leakage.
• For sensitive data, it is still necessary to check the service provider’s data policy.

Which users are it suitable for

• Ordinary users who read foreign language news and technical materials.
• Students and researchers who consult papers, monographs, and databases.
• Learners who watch videos of foreign language courses and interviews.
• Professionals who work with multilingual documents.
• Creators who need to produce bilingual e-books and subtitles.
• For advanced users who wish to choose their own translation engine.

Product advantages

• Bilingual comparison with the original verification path retained.
• Websites, videos, documents, and input fields are all fully covered.
• Supports multiple platforms and a large number of translation engines.
• PDF Pro and BabelDOC are used to handle complex documents.
• Hover translation is suitable for partial reading and helps save data usage.
• Advanced users are allowed to configure custom APIs.

Usage restrictions and precautions

• AI translations may misinterpret context and technical terms.
• Advanced models and complex document features require a membership.
• Each account can use up to 8 browser devices simultaneously.
• The files may be processed by third-party service providers.
• Personal information may involve cross-border storage and processing.
• The current main product is not open-source software.
• Medical, legal, and contractual translations must be reviewed manually.

Frequently Asked Questions

What can immersive translation mainly do?

It supports bilingual translation for web pages, video subtitles, input fields, hover text, PDFs, e-books, and various other documents.

Can immersive translation be used for free?

Yes, the basic web pages and some document functions can be used for free, while advanced models and capabilities for handling complex PDF files require a membership.

How much do Immersive Translation Pro and Max cost?

On August 30, 2026, the Pro version will cost 69 yuan per month or 579.6 yuan per year, while the Max version will cost 199 yuan or 1599 yuan per year.

Does immersive translation support scanned PDFs?

Yes, PDF Pro offers OCR and advanced formatting capabilities, while BabelDOC focuses on creating high-fidelity bilingual documents.

How many devices can a membership account be logged into?

Each account can use up to 8 browser devices simultaneously; once this limit is reached, the device that was logged in first will be disconnected.

Will the uploaded documents be sent to third parties?

It’s possible; the member’s PDF might be sent to Mathpix for analysis, and the translated text will be sent to the translation engine chosen by the user.

Is immersive translation open-source software?

The current product is not open-source software; the official GitHub repository is used only for releasing versions and collecting issues, and it does not contain the source code.