Select the language you are learning. The site language above sets the language of explanations.Explanations in EnglishRubi Japanese
Browser extensions and a macOS application
Read the web in the language you are learning.
Rubi places pronunciations, readings, glosses and context-aware AI explanations directly on the page: on any website, in YouTube and Bilibili videos, and in every application on macOS.
One application covers all four editions and connects to the installed Rubi extensions automatically.
雨が降りそうなので、it looks like rain, so傘を持ってtake an umbrella出かけたほうがいいですよ。you’d better head out
It looks like rain, so you’d better take an umbrella when you go out.
Reading
Every word, explained in its sentence.
Point to a word on any page. Rubi answers from local dictionaries first, then offers an AI explanation grounded in the sentence being read.
雨が降りそうなので、傘を持って出かけたほうがいいですよ。
It looks like rain, so you’d better take an umbrella when you go out.
The responses on this page are prerecorded. No request is sent to any service.
Video
Study YouTube and Bilibili one line at a time.
Select the Rubi control in the player bar to turn captions into a bilingual transcript that can be looped, stepped through from the keyboard and mined for vocabulary.
今日は駅の近くの小さなカフェに来ています。
Today I’m at a little café near the station.
- Space Play or pause
- ← Previous line
- → Next line
- L Loop the line
The key assignments shown are provisional and may change before release.
Rubi for macOS
The same assistance in every application.
Mail, PDF readers, messaging applications, games and video players: any text that can be selected or seen on screen can be read with Rubi.
Select text in any application and press the shortcut. A panel appears beside the selection with the translation, readings and an AI explanation, and can follow the pointer.
雨が降りそうなので、傘を持って出かけたほうがいいですよ。
It looks like rain, so you’d better take an umbrella when you go out.
- 傘かさumbrella
- 持ってもってto hold, to carry
- 出かけたでかけたto go out
Download
Editions and platforms
One extension for each learning language, and one macOS application that serves all four.
To install from an archive: extract it, open chrome://extensions, enable Developer mode and choose “Load unpacked”.
Rubi for macOS macOS
Floating panel, screen capture and writing assistance for English, Japanese, Korean and Chinese. The language is selected in the application’s settings.
One application covers all four editions and connects to the installed Rubi extensions automatically.
Getting started
- 1
Install
Add the extension for your learning language, the macOS application, or both.
- 2
Grant access
On macOS, allow Accessibility for selected text and Screen Recording for screen capture. In the browser, allow the extension to connect to the application.
- 3
Choose an AI mode
Enter your own API key at no charge, or activate Rubi Pro with a license key.
Pricing
Plans
Rubi is free of charge. Rubi Pro is for users who prefer not to manage an API key of their own.
Free · Custom API key
$0 no time limit
- Machine translation at no charge
- Local dictionaries: IPA, readings, dictionary forms, KRDict
- Anki and Eudic integration
- AI explanations with your own API key from any OpenAI-compatible provider
- No account required
AI requests travel directly from your device to the provider you configured. None of them pass through Rubi’s servers.
DownloadRubi Pro · Monthly Monthly
US$1.49per month
Settled in CNY through Alipay · ¥9.90
Hosted AI without configuration, approximately 4,000 word lookups per month, on every device.
- Hosted AI without an API key
- Approximately 4,000 word lookups per month; longer translations use more of the allowance
- One license key for all four extensions and the macOS application
- Everything in the free plan
With Rubi Pro, AI requests pass through Rubi’s gateway. Only usage counts are recorded; prompts and responses are not stored.
Rubi Pro · Annual Annual · ¥20 less
US$14.90per year
Settled in CNY through Alipay · ¥100.00
Equivalent to ¥8.33 per month. Intended for continuous study across the browser and macOS.
- Hosted AI without an API key
- Approximately 4,000 word lookups per month; longer translations use more of the allowance
- One license key for all four extensions and the macOS application
- Everything in the free plan
With Rubi Pro, AI requests pass through Rubi’s gateway. Only usage counts are recorded; prompts and responses are not stored.
The monthly allowance resets on the first day of each month (UTC). Renewing with an existing key, or with the same email address, extends the current expiry date.