Bilibili Subtitle Downloader
Pulls B站 subtitle tracks as clean .srt or .ass, keeps danmaku in its own file, and falls back to local Whisper when a video ships no subtitles at all.
Why download Bilibili Subtitles videos with ViralMint?
Bilibili does not embed subtitles in the video the way YouTube does. Its CC tracks are served as JSON from a separate api.bilibili.com endpoint, keyed to the video's internal cid rather than its BV id — which is why browser extensions that scrape the player usually come back empty, and why a multi-part video needs one subtitle fetch per part rather than one per URL. ViralMint resolves the cid for every page in a series, converts each track to .srt or .ass, and keeps danmaku (弹幕) in a separate .xml so the comment stream never contaminates the caption file. Two Bilibili-specific gaps matter more than the mechanics: a large share of B站 uploads carry no subtitle track at all, and community bilingual subs are often burned into the picture rather than served as data. For both, the app transcribes the audio with local Whisper instead — no API key, nothing uploaded, Mandarin plus 100+ other languages. If you only want the video file, use the Bilibili video downloader.
How to download from Bilibili Subtitles
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Copy the Bilibili Subtitles video URL
From bilibili.com, copy the share or page URL — e.g.
https://www.bilibili.com/video/BV1xx411c7mD -
Paste it into ViralMint
Open the ViralMint desktop app and paste the URL into chat. The planner detects the Bilibili Subtitles URL and triggers the download automatically — no flags, no command line.
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Get the mp4, transcript and AI insights
The video lands in the Videos page with a local Whisper transcript and AI-extracted hook / structure / tone — ready for clip extraction or repurposing.
Frequently Asked Questions
The video has no subtitle track. Can I still get one?
Yes, and this is the common case on B站 — a large share of uploads never get a CC track. ViralMint runs Whisper on your own machine to transcribe the audio and writes a normal .srt you can edit or translate. Nothing is uploaded, there is no API key, and Mandarin accuracy is the same as any other supported language.
What is the difference between the .srt, .ass and danmaku files?
The .srt is the plain caption track — timings plus text, the format every editor accepts. The .ass keeps Bilibili's original positioning and styling, which matters when a track places lines away from the bottom of the frame. Danmaku is not a subtitle at all: it is the scrolling comment stream, saved as .xml so you can study where viewers reacted without burning the overlay into the picture.
Does it work with Bstation, the international app?
Yes. Bstation is Bilibili's overseas brand and it serves subtitles from the same backend, so a bilibili.tv link resolves the same way a bilibili.com one does. Region-limited titles still need your account cookies — export them via Settings → Cookies and the app inherits whatever your account can see.
How ViralMint compares to other Bilibili Subtitles downloaders
| Approach | Examples | Trade-off | ViralMint advantage |
|---|---|---|---|
| Online converters | Y2mate, SaveFrom, ssyoutube, OnlineVideoConverter | Pop-up ads, redirects, quality capped at 720p, file-size limits, no batch downloads, your URL logged to ad networks | Local app, zero ads, original quality (up to Original CC track (srt, ass, json)), unlimited file size, batch mode |
| Browser extensions | Video DownloadHelper, FastestTube, similar Chrome / Firefox add-ons | Routinely broken after Bilibili Subtitles updates, removed from stores for ToS violations, no transcript or AI analysis | Updates with yt-dlp upstream (community-maintained), independent of browser extension stores, Whisper transcript built in |
| yt-dlp command line | yt-dlp, youtube-dl | Most flexible option but requires terminal comfort, manual cookie handling, no GUI for batch selection | Same yt-dlp under the hood, wrapped in a desktop GUI with cookie auto-detect, batch UI, and post-processing pipeline |
| Closed-source desktop apps | 4K Video Downloader, Allavsoft, ByClick Downloader | Closed-source, paid tiers gate batch and HD, no AI pipeline, no extensible Whisper / FFmpeg post-processing | Open source (AGPL-3.0), AI features prepaid per-action, integrates with the rest of the ViralMint creator pipeline |
Supported URL Example
https://www.bilibili.com/video/BV1xx411c7mDEquivalent yt-dlp command
If you already use yt-dlp, the desktop app's Bilibili Subtitles download is equivalent to running:
yt-dlp -f "bv*+ba/b" --merge-output-format mp4 "https://www.bilibili.com/video/BV1xx411c7mD"ViralMint also auto-runs Whisper transcription, downloads the thumbnail, and extracts AI hook / structure / tone insights — steps that take a separate command chain in raw yt-dlp.