Subtitle Translator is a free, open-source tool for batch translating subtitle files (.srt, .ass, .vtt) across 35+ languages. It targets content creators, educators, and filmmakers seeking efficient, high-speed subtitle localization, offering features like translation caching and multi-language output from a single file.

How It Works

The tool leverages chunked compression and parallel processing for real-time translation speeds, aiming for 1-second per episode. It integrates with multiple translation services, including DeepL, Google Translate, Azure Translate, and free GTX options, alongside five AI LLM models (OpenAI, Groq, etc.) for enhanced accuracy and stylistic control. Translation caching stores results locally to minimize redundant API calls and costs.

Quick Start & Requirements

• Install/Run: yarn install then yarn dev for local development, or yarn build && yarn start.
• Prerequisites: Node.js 18.18 or later. macOS, Windows (including WSL), Linux supported.
• API Keys: Required for commercial APIs (DeepL, Google, Azure). Keys are stored locally in the browser.
• Online Demo: https://tools.newzone.top/en/subtitle-translator

Highlighted Details

• Supports batch processing of hundreds of subtitle files.
• Offers translation caching to save time and API costs.
• Handles .srt, .ass, and .vtt formats with automatic adaptation and encoding detection.
• Enables translating a single file into multiple target languages simultaneously.

Maintenance & Community

The project is actively developed, with plans for a standalone desktop version and AI-powered refinement. Users are encouraged to contribute or suggest improvements.

Licensing & Compatibility

The project is licensed under the MIT License, permitting commercial use and integration with closed-source projects.

Limitations & Caveats

DeepL API requires a server-side proxy (provided or self-hosted) as it doesn't support direct web usage. GTX Web API runs locally and should not be used in global proxy mode to avoid errors.