Immersive Translate — Bilingual Web Page Translation Extension

Introduction

Immersive Translate is a browser extension that displays bilingual translations directly on web pages. Rather than replacing the original text, it renders the translation below each paragraph so you can read both languages side by side. It supports multiple translation engines including Google, DeepL, and OpenAI.

What Immersive Translate Does

• Translates web pages inline, displaying both the original and translated text together
• Supports PDF document translation with bilingual side-by-side output
• Translates video subtitles on YouTube and other platforms in real time
• Works with multiple translation backends: Google, DeepL, Microsoft, OpenAI, and others
• Translates ebooks in EPUB format with bilingual output for language learners

Architecture Overview

The extension injects content scripts into web pages to detect and extract text nodes. It batches the text and sends it to the selected translation API, then inserts the translated text as styled elements below the original content. A background service worker manages API keys, rate limiting, and caching. The popup UI lets users switch translation engines and configure display settings.

Self-Hosting & Configuration

• Install from Chrome Web Store, Firefox Add-ons, or sideload from GitHub releases
• Configure your preferred translation engine in the extension settings panel
• Add custom API keys for DeepL, OpenAI, or other paid translation services
• Set per-site rules to auto-translate specific domains on page load
• Adjust translation display style: underline, highlight, or block mode

Key Features

• Bilingual display: original and translated text shown together for context
• Multi-engine support: switch between Google, DeepL, OpenAI, and others
• PDF translation: bilingual PDF reading directly in the browser
• Subtitle translation: real-time bilingual subtitles for online videos
• EPUB support: translate ebooks while preserving formatting

Comparison with Similar Tools

• Google Translate extension: replaces original text entirely; Immersive Translate keeps both
• DeepL extension: limited to DeepL engine only; this supports many backends
• TWP (Translate Web Pages): basic page translation; lacks PDF and subtitle support
• Mate Translate: dictionary-focused; Immersive Translate handles full-page bilingual output

FAQ

Q: Is Immersive Translate free? A: The core extension is free and open source. Some premium translation engines may require your own API keys or a subscription.

Q: Which browsers are supported? A: Chrome, Firefox, Edge, Safari, and other Chromium-based browsers are supported.

Q: Can I use my own OpenAI API key? A: Yes. You can configure a custom API key in the settings to use OpenAI or other LLM-based translation services.

Q: Does it work on mobile browsers? A: It supports some mobile browsers that allow extensions, such as Firefox for Android and Kiwi Browser.

Sources

• Repository: https://github.com/immersive-translate/immersive-translate
• Documentation: https://immersivetranslate.com/docs/