Description
A foreign-language lecture with no subtitles usually means juggling four or five tools: transcribe in one, export and translate in another, re-sync in your editor, burn in with yet another. SmartSub folds the whole chain into one desktop app. Drop in a video, let local Whisper-class models transcribe it offline, translate to bilingual subtitles, proofread, and burn them in, with your files never leaving the machine.
Paste a Bilibili or YouTube link and it downloads the video itself, pairing the platform's official subtitles when they exist so you can skip transcription. To make a foreign-language version, it can synthesize dubbing line by line from the subtitles, even cloning your own voice from a short reference clip, with GPU acceleration on NVIDIA, AMD, Intel and Apple silicon.
Online video download: batch-download one link per line, with yt-dlp and lux engines picked automatically per site; import cookies to unlock login-only HD and members content, stored locally only.
Offline transcription: whisper.cpp, faster-whisper, FunASR, Qwen3-ASR and more, switchable per task, with cloud recognition as an option. Optional AI refinement re-segments by meaning and fixes homophone errors.
Subtitle translation: a built-in free translation source gives bilingual subtitles without any API key, or plug into 20 services including Baidu, DeepL, DeepSeek and local Ollama models, or any OpenAI-compatible endpoint.
Proofreading desk: check and edit line by line against the video, with undo and redo, recoverable deletions and one-click AI polishing.
Dubbing and voice cloning: offline free Kokoro and VITS voices, zero-shot cloning from one reference clip with ZipVoice, automatic timeline alignment, plus cloud options such as Edge TTS, Azure and ElevenLabs.
Subtitle burn-in: hard subtitles baked into the picture, or soft subtitle tracks muxed losslessly, with live WYSIWYG styling of font, color, outline and position.
AI assistant: press Cmd/Ctrl+J for a side panel that sees the playback position, the selected line and the error log, so one sentence can make the current line more colloquial or diagnose a failed task from a screenshot.
MCP and CLI: 111 MCP tools and matching smartsub commands let agents like Cursor and Claude Code, or plain shell scripts, run the whole pipeline in batch with no separate Node.js install.
Cross-platform: installers for Windows, macOS and Linux, MIT licensed.
Paste a Bilibili or YouTube link and it downloads the video itself, pairing the platform's official subtitles when they exist so you can skip transcription. To make a foreign-language version, it can synthesize dubbing line by line from the subtitles, even cloning your own voice from a short reference clip, with GPU acceleration on NVIDIA, AMD, Intel and Apple silicon.
Features
Online video download: batch-download one link per line, with yt-dlp and lux engines picked automatically per site; import cookies to unlock login-only HD and members content, stored locally only.
Offline transcription: whisper.cpp, faster-whisper, FunASR, Qwen3-ASR and more, switchable per task, with cloud recognition as an option. Optional AI refinement re-segments by meaning and fixes homophone errors.
Subtitle translation: a built-in free translation source gives bilingual subtitles without any API key, or plug into 20 services including Baidu, DeepL, DeepSeek and local Ollama models, or any OpenAI-compatible endpoint.
Proofreading desk: check and edit line by line against the video, with undo and redo, recoverable deletions and one-click AI polishing.
Dubbing and voice cloning: offline free Kokoro and VITS voices, zero-shot cloning from one reference clip with ZipVoice, automatic timeline alignment, plus cloud options such as Edge TTS, Azure and ElevenLabs.
Subtitle burn-in: hard subtitles baked into the picture, or soft subtitle tracks muxed losslessly, with live WYSIWYG styling of font, color, outline and position.
AI assistant: press Cmd/Ctrl+J for a side panel that sees the playback position, the selected line and the error log, so one sentence can make the current line more colloquial or diagnose a failed task from a screenshot.
MCP and CLI: 111 MCP tools and matching smartsub commands let agents like Cursor and Claude Code, or plain shell scripts, run the whole pipeline in batch with no separate Node.js install.
Cross-platform: installers for Windows, macOS and Linux, MIT licensed.
