How to Enable Dual Subtitles on Bilibili: A Guide to Bilingual Captions and Real-Time Translation

When watching overseas tech talks, open courses, game previews, or imported foreign videos on Bilibili (B站), viewers often run into two major frustrations: first, videos frequently lack creator-hardcoded Chinese subtitles, leaving viewers to rely entirely on listening comprehension when watching untranslated raw content; second, even when creators or the platform provide foreign subtitles, the default player usually does not allow viewing the original transcription and Chinese translation at the same time.

To understand how to enable dual subtitles and real-time audio translation in the browser, it is essential to first clarify the practical scope and limitations of existing approaches, and then pair them with the right player companion tool.

Practical Use Cases and Differences Among Existing Approaches

When watching foreign-language content on Bilibili, subtitle solutions generally fall into two categories:

1. Platform-Native and Auto-Generated Subtitles

• Use Cases: Videos where the creator uploaded standardized foreign SRT/ASS subtitle tracks, or select videos where Bilibili's backend automatically extracted and generated captions.
• Limitations and Differences: Coverage depends entirely on whether the creator uploaded subtitle tracks or whether the platform backend processed the video. Currently, the native player only allows selecting a single display language at a time; switching to Bilibili's auto-translated Chinese replaces and hides the original foreign text. For viewers looking to cross-check technical terminology against the original text, learn pronunciation, or verify technical details, single-language display is inconvenient. In addition, for untranslated raw videos without subtitles, native captioning provides no immediate help.

2. Traditional Web Page Translation Extensions

• Use Cases: Browsing static web pages or translating selected words and text nodes across entire web pages.
• Limitations and Differences: Most general-purpose translation extensions rely on reading and replacing existing DOM text nodes on the page; they cannot read video audio streams directly. When faced with raw videos that lack text subtitle tracks entirely, general translation tools cannot provide speech recognition or real-time translation.

---

Enabling Dual Subtitles on Bilibili with Equalang

Using the Equalang browser extension, you can display bilingual subtitles side by side in the Bilibili web player or generate real-time audio translations for videos that lack subtitles.

1. Bilingual Subtitle Comparison for Videos with Existing Subtitles

For videos that already include foreign subtitle tracks, the primary goal is displaying the original foreign sentences and Chinese translation on separate lines on screen for easy comparison:

1. After enabling the extension in a Chromium-based browser or Firefox, open a Bilibili video that contains foreign subtitles.
2. The Equalang icon will automatically appear in the bottom-right control bar of the player. Click the icon to expand the panel and enable subtitle translation.
3. Under subtitle display mode, select either 'Dual Subtitles' or 'Translation Only'; you can position the translation 'Below Original' or 'Above Original' based on your reading preference.
4. Once configured, the player will display the foreign original text and Chinese translation simultaneously.

2. Real-Time Audio Translation for Untranslated Raw Videos

When encountering imported foreign videos or clips that have no subtitle tracks at all, you can use the real-time audio translation feature to convert the audio track directly into subtitles:

1. Open an untranslated foreign video, then toggle on 'Real-Time Audio Translation' in the Equalang panel at the bottom right of the player.
2. Set the source language to 'Auto-detect' or the appropriate language, and keep the translation mode on 'Standard'.
3. The extension will transcribe the speech in the video into text and generate corresponding Chinese translations in real time.

We opened an untranslated Japanese beginner conversation collection on Bilibili and enabled real-time audio translation (source language set to 'Auto-detect', translation mode 'Standard', subtitle display 'Dual Subtitles', translation position 'Below Original'). During playback, two lines of subtitles appeared at the bottom of the video in real time: the original Japanese on top and the Chinese translation below.

---

Usage Recommendations and Known Limitations

When using translation tools to watch foreign videos, keep the following technical boundaries and limitations in mind:

1. Background Audio and Mixing Interference: The accuracy of real-time speech translation depends heavily on vocal clarity. If a video features loud background music (BGM), intense gaming sound effects, or overlapping multi-speaker dialogue, speech segmentation and sentence boundary detection can be disrupted, leading to dropped words or transcription inaccuracies.
2. Encrypted DRM Content: Encrypted videos cannot undergo real-time audio translation. However, if the video provides a text subtitle track, subtitle text can still be translated.
3. Subtitle Track Dependency: When real-time audio translation is disabled, subtitle translation relies entirely on the subtitle tracks provided by the video. If a video neither has a foreign subtitle track nor has real-time audio translation enabled, text cannot be extracted or translated.

---

Sources

• Bilibili Help Center: Video Player and Subtitle Settings: https://www.bilibili.com/blackboard/help.html
• Equalang Browser Extension (Supported Platforms List and FAQ): https://equalang.com/extension