Tools

Translates full PDF papers while preserving formulas, charts and layout (command pdf2zh), outputting monolingual and side-by-side bilingual PDFs. Uses Google Translate by default and can switch to DeepL, OpenAI and others; also runs as an MCP server.

Offline speech transcription and translation based on Whisper; audio never leaves your machine. buzz add exports lectures, interviews and meeting recordings to TXT, SRT or VTT. pip install needs Python 3.12 and FFmpeg; a desktop app is also available. Check transcripts manually.

CLI version of the VideoCaptioner subtitle assistant: transcribes courses, lectures and interviews, uses an LLM to segment, proofread and translate, then burns subtitles into the video. Free ASR and Bing translation work out of the box; LLM refinement needs an API key. Python 3.10 to 3.12.

Open-source grammar, spelling and style checker for 20+ languages including English, German, French, Spanish and Portuguese. Proofread drafts in bulk from the CLI or run a local HTTP checking server for agents. For writers, translators and language teachers. Needs Java 17 (Homebrew includes it).

Uses LLMs to translate EPUB, TXT, Markdown, SRT, PDF and other files into side-by-side bilingual editions, via OpenAI, Anthropic, Gemini and other APIs or DeepL and Google Translate. LLM APIs need your own key or a Codex subscription. Only translate content you have rights to.

PDF translation CLI for research papers that preserves formulas and layout as much as possible, producing bilingual side-by-side or translation-only PDFs. Needs an OpenAI-compatible API (local Ollama works too); currently focused on English to Chinese.

Extracts subtitles burned into videos to SRT or TXT, with all OCR done locally in 87 languages. Mainly a GUI (with batch mode); the CLI backend/main.py reads the video path and subtitle area from stdin. Needs Python 3.12+ and PaddlePaddle; paths cannot contain spaces or Chinese characters.

PDFMathTranslate 2.x (command pdf2zh_next), built on BabelDOC: translates papers and other PDFs while keeping formulas, charts, TOC and annotations, outputting translated and bilingual side-by-side versions. Uses a free translation channel by default, or your own OpenAI, DeepSeek or other API key.

Translates a video's SRT subtitles into other languages and generates AI voice lines synced to the timings, producing translated subtitles and dubbed audio tracks. Needs Python, FFmpeg and Google Cloud, Azure, DeepL or ElevenLabs API keys; configure the ini files, then run python main.py.

Chinese-English translation and word lookup in the terminal: one command shows definitions, phonetics and examples from iCiba, Youdao and an LLM. No API key needed (built-in free LLM proxy), or use any OpenAI-compatible model. Needs Node.js 20+; queries are sent to these online services.

Local LLM-powered document translator for PDF, Word, Excel, EPUB, SRT subtitles and more; Word and Excel keep their formatting, glossaries can be built automatically, and agents can submit jobs via MCP. Needs uv and an OpenAI-compatible API key; translated PDFs lose the original layout.

The standard machine translation scorer: computes BLEU, chrF and TER with significance tests and downloads public test sets such as WMT, to compare engines or prompts. Needs Python 3.9+ and reference translations; automatic metrics are a rough screen, so final copy still needs human review.

Open-source video translation and dubbing: transcribes lectures, courses and other videos, translates them into one of 33 languages, synthesizes a dub aligned to the picture, and can export SRT subtitles. Needs Python 3.10+, FFmpeg, the violin CLI and a pay-as-you-go Together AI API key.

Creates and edits local CapCut (JianYing) drafts from the terminal: rough cuts on silence, styled subtitles and multilingual versions, still editable track by track in CapCut. Needs Node 18+ and desktop CapCut; subtitles need Whisper, translation an Anthropic key. No encrypted drafts. Unofficial.

Unbabel's machine-translation quality metric: comet-score rates translations per sentence and overall, XCOMET marks error spans and severity, and CometKiwi works without a reference. Good for spot-checking MT. Needs Python 3.8+; models download from Hugging Face, some need a license; GPU helps.

Microsoft Azure's official tool for translating Markdown, Jupyter notebooks and image text into 50+ languages; re-translates only changed parts and keeps links and formatting. Needs Python 3.11+ and an Azure OpenAI, OpenAI or Anthropic key; images need Azure AI Vision.

Official HeyGen skill: translates existing videos into 175+ languages with dubbing that clones the speaker's voice and re-syncs lips; you can proof subtitles before rendering. Needs a HeyGen account with credits and an API key plus HeyGen CLI, or the HeyGen MCP.

Post-draft polishing skills for English LaTeX papers, Chinese theses (GB/T 7714) and Typst manuscripts: compile diagnostics, format and grammar checks, reference verification, reviewer-style assessment, cover letters and defense slides. Needs Python, uv and TeX Live; academic use only.

Official ElevenLabs skills: text to speech, speech to text, sound effects and music generation, voice changing, vocal isolation, multilingual dubbing and building voice agents. Needs an ElevenLabs API key.

HeyGen's official CLI, built for agents like Claude Code and Codex: generate avatar presenter videos from a prompt or template, translate and dub videos, and synthesize speech, with JSON output. Good for batch training and product videos. Needs a HeyGen API key (usage-billed) or a Pro/Max plan.

Microsoft Translator's translation quality tool: GPT scores each sentence using MQM error categories or a direct score; --list_mqm_errors shows error types and severity. Needs line-aligned source and target files, Python and an OpenAI or Azure OpenAI key (paid); a translator should still review.