# Shinkansen - Blazing fast web & YouTube translator > Shinkansen uses AI models to translate web pages and YouTube subtitles. Text is replaced in place to preserve the page layout, and connects directly to the AI model — your data never passes through any third party. Canonical page: [https://chrome-stats.com/d/shinkansen](https://chrome-stats.com/d/shinkansen) ## Overview - **ID:** `shinkansen` - **Platform:** Firefox - **Type:** Firefox add-on - **Status:** Available - **Publisher:** Jimmy Su - **Category:** language-support - **Daily users:** 104 - **Weekly downloads:** 7 - **Rating:** 5.00 / 5 (4 ratings) - **Version:** 2.4.0 - **Last updated:** 2026-08-20 - **First published:** 2026-04-30 - **Size:** 11 MB - **Data as of:** 2026-09-06 - **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/shinkansen/) - **Website:** [https://github.com/jimmysu0309/shinkansen/issues](https://github.com/jimmysu0309/shinkansen/issues) ## Description Recently added: • New floating button: tap to translate the page, long-press to switch translation engines or open the menu • New Send to Instapaper: save the entire translated article to Instapaper in one click for later re-reading • iOS / iPadOS version coming soon to the App Store — stay tuned Highlights: • Privacy-first — connects directly to Google, no third-party servers in between • Open source — the code is public on GitHub, so anyone can audit its security • Multilingual translation + multilingual UI — Traditional Chinese / Simplified Chinese / English / Japanese / Korean / Spanish / French / German Web page translation • Instant streaming: the page starts changing into your language within 1 second of pressing translate — no waiting for the full API batch to return (Gemini only) • Translated paragraphs are cached automatically, so re-translating costs nothing • Two display modes: "Monolingual" replaces text in place; "Bilingual" shows the original and translation side by side • Edit translations: after translation completes, edit the translated text directly on the page to polish rough spots before exporting to PDF • Multilingual translation + multilingual UI — Traditional Chinese / Simplified Chinese / English / Japanese / Korean / Spanish / French / German • Translate-the-opening option: translate only the first N paragraphs as a preview, saving a large amount of tokens PDF translation (beta) • Analyzes the layout locally, sends the text for translation, and presents the result in a side-by-side two-page comparison view • The entire document is processed inside your browser — nothing is ever uploaded to any server • Edit PDF translations: edit the translated text paragraph by paragraph inside the reader, then save to regenerate the two-page preview • Document glossary: before translating, ask the AI to extract a glossary of names and proper nouns from the document; confirm or edit it, then translate — keeping terminology consistent throughout the entire document YouTube caption translation • Translates YouTube captions in real time, with caption styling that matches native YouTube • AI smart sentence segmentation: auto-generated (ASR) captions are re-segmented by meaning, turning fragmented short lines into readable full sentences • Bilingual captions: original + translation shown on two lines at once — great for listening practice Three translation shortcuts / three engines • Alt+A / Alt+S / Alt+D each bind to a preset translation engine • Gemini AI (best quality, requires an API key) • Google Translate (free machine translation, no API key needed, faster) • Custom AI model (OpenAI-compatible — connect to hundreds of models via OpenRouter / Claude / DeepSeek / Groq / local Ollama, and more) Translation quality control • Fixed glossary: force specific terms to always be translated the way you specify (global + per-domain layers) • Customizable banned-word list: explicitly tell the LLM which words it must never use • Document-wide terminology consistency: names and proper nouns stay consistent throughout long articles • Translate-the-opening option: translate the first few paragraphs as a preview before deciding whether to read on, saving a large amount of tokens Auto-translate and cross-page continuation • Auto-translate specified sites: add a domain and pages are translated automatically on entry • Cross-tab continuation: open a link from a translated page in a new tab, and the new tab is translated automatically with the same preset Usage tracking and savings reports • Records token counts, cost, and cache hit rate for every translation, with charts and CSV export • Two-layer caching (local cache + Gemini implicit context cache), with cache hit rate and actual savings shown right after each translation ## Rankings - #11,514 — Overall - #93 — fast vpn - #112 — fragment - #214 — deepseek - #214 — translate - #230 — translations ## Permissions and access ### Permissions - `storage` - `alarms` - `webNavigation` ### Host permissions - `` - `https://generativelanguage.googleapis.com/*` - `https://translate.googleapis.com/*` - `https://www.instapaper.com/*` ### Content script matches - `www.youtube.com` - `m.youtube.com` - `` - `youtube.googleapis.com` ## Safety - **Risk impact:** Very high risk impact - **Risk likelihood:** High risk likelihood ### Analysis details - Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site. - This extension was recently updated in the past month. New updates may not be stable or safe. > Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing). ## Similar extensions and apps - [Mira Translator - Web Translation](https://chrome-stats.com/d/mira-translator) — 45 users, 5.00 / 5 - [AI Page Translator](https://chrome-stats.com/d/ai-page-translator) — 24 users - [Anylang Translator](https://chrome-stats.com/d/anylang-translator) — 1 users - [YouTube Bilingual Subtitles — AI](https://chrome-stats.com/d/youtube-bilingual-subtitles-ai) — 2 users - [YouSub](https://chrome-stats.com/d/yousub) — 12 users - [Youtube Dubbing](https://chrome-stats.com/d/youtube%E4%B8%AD%E6%96%87%E9%85%8D%E9%9F%B3) — 3,264 users, 3.92 / 5 - [Dual Subtitles & AI Translation - InterSub](https://chrome-stats.com/d/intersub) — 1,441 users, 3.85 / 5 - [Subly.xyz - AI Translator](https://chrome-stats.com/d/subly-xyz) — 10 users - [AI Daily Tools](https://chrome-stats.com/d/ai-daily-tools) — 1 users - [Replace AI Translator API](https://chrome-stats.com/d/replace-translator) — 1 users - [AI Subtitle Translator](https://chrome-stats.com/d/ai-subtitle-translator) — 19 users - [AI Actions](https://chrome-stats.com/d/ai-actions) — 6 users, 5.00 / 5 --- Source: [Chrome-Stats](https://chrome-stats.com/d/shinkansen)