SubFlow

A desktop subtitle studio — download, translate, and generate TTS audio from online videos or local subtitle files.

Built with Tauri v2 + React + Rust.

Features

• Subtitle download — YouTube, and any platform supported by yt-dlp (1000+ sites)
• Local subtitle files — drag-and-drop SRT, VTT, TXT files
• Multi-provider translation — Anthropic (Claude), OpenAI, Google Gemini, GLM (Zhipu AI), DeepL, LibreTranslate, OpenAI-compatible APIs
• NLLB-200 local translation — offline translation via CTranslate2, no API key needed (600M and 1.3B models)
• Text-to-Speech — Edge TTS (free, 100+ languages) and OpenAI TTS
• Batch processing — queue multiple videos/files with parallel jobs
• Multi-language output — translate to multiple target languages in a single task
• Processing modes — Subtitle Only, Sub + Translation, Sub + Translation + TTS
• YouTube auto-translated subtitles — experimental support via yt-dlp browser impersonation
• Desktop notifications — get notified when tasks complete or fail
• i18n — English and Vietnamese

Tech Stack

Layer	Technology
Framework	Tauri v2
Frontend	React 19, TypeScript, Tailwind CSS v4, Zustand
Backend	Rust
UI	shadcn/ui, Radix UI, Lucide icons, Sonner toasts
TTS	msedge-tts, OpenAI Audio API
Translation	Anthropic, OpenAI, Gemini, DeepL, LibreTranslate, CTranslate2 (NLLB)

Prerequisites

• Node.js >= 18
• pnpm
• Rust (stable)
• Tauri v2 system dependencies — see Tauri prerequisites

Development

# Install dependencies
pnpm install

# Run in development mode
pnpm tauri dev

# Build for production
pnpm tauri build

Runtime Dependencies

SubFlow manages these automatically via the in-app Dependencies panel:

Dependency	Purpose	Auto-install
yt-dlp	Video/subtitle download (1000+ sites)	Yes
ffmpeg	Media processing	Yes
curl_cffi	Browser impersonation for YouTube auto-translated subs	Yes (requires Python 3)
NLLB-200 600M	Local translation model (~2.5 GB)	Manual download
NLLB-200 1.3B	Higher quality local translation (~5.5 GB)	Manual download

Project Structure

src/                    # React frontend
  components/           # UI components
  stores/               # Zustand state management
  hooks/                # Custom React hooks
  lib/                  # Utilities, types, Tauri API bindings
  i18n/                 # Internationalization (en, vi)
src-tauri/              # Rust backend
  src/
    subtitle/           # SRT/VTT/TXT parser & writer
    youtube/            # yt-dlp integration, Innertube API
    translate/          # Translation providers
    tts/                # TTS providers (Edge, OpenAI)
    queue/              # Task orchestrator
    commands/           # Tauri IPC commands

License

MIT