1. Introduction
Vocab is a vocabulary-learning Chrome extension. It saves words and phrases you select
while reading, highlights them on the pages you visit, and explains them — with
translation, meaning, examples, synonyms, pronunciation, and related words — using the
AI provider you configure or a keyless translation endpoint.
Vocab is local-first by design: there is no account system, no backend server operated
by the developer, and no telemetry. This policy explains what information Vocab
accesses, where that information is stored, and when it leaves your browser.
2. Data Stored Locally
All of your vocabulary and learning data is stored locally in your browser:
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Your vocabulary library — saved words and phrases with their
surrounding sentence, source page URL and title, your notes, tags, favourites, and
timestamps — is stored in IndexedDB in your browser profile.
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Your settings — the AI provider and model you chose, target
language, highlighting and display preferences — are stored in
chrome.storage.local.
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Backups you create yourself — versioned JSON exports and imports —
are files you choose to make and move.
Vocab does not operate a developer-managed backend for storing this information. There
is no account, no cloud sync, and nothing in this list is uploaded to a server operated
by this project.
3. Webpage Content
When you select a word or phrase and use a Vocab feature, the extension reads the
selected text — and, when saving, the surrounding sentence and the page's title and URL —
to carry out the action you requested. This access is necessary to provide translation,
vocabulary explanations, examples, synonyms, pronunciation, AI enrichment, and
vocabulary highlighting.
To highlight your saved words, Vocab scans the text of the page you are currently on,
locally in your browser. Vocab does not continuously record your browsing history, and
it does not monitor the pages you visit beyond what its vocabulary features require.
4. AI Providers
When you request an AI-powered feature, the relevant text — the word or phrase, its
context, and your current prompt settings — is sent directly from the extension to the
AI provider you configured. Vocab supports OpenAI, OpenRouter, DeepSeek, Mistral, Groq,
Together, Google Gemini, Anthropic, LM Studio, Ollama, and custom OpenAI-compatible
endpoints.
These requests go straight from your browser to the provider you chose. Vocab does not
relay them through its own server, and it does not control or store data on those
providers' systems. Inline translation without a configured AI key uses a keyless public
translation endpoint (Google), also called directly from your browser.
Your use of any provider is subject to that provider's own privacy policy and terms of
service — please review them for details such as how they handle or retain data. This
policy does not make claims about the data retention practices of third-party
providers.
5. API Credentials
If you add an API key for a hosted AI provider, the key is stored locally in your
browser (chrome.storage.local) and is sent only to the provider you
selected, only when you initiate a request to that provider. Your key is never sent to
a Vocab-operated server — Vocab does not operate one — and it is never shared with other
providers.
Treat your API key like any credential: it is only as protected as your browser
profile. You can remove or replace it at any time in Settings, or use a local model
(Ollama or LM Studio) that requires no key at all.
6. Data Sharing
Vocab does not sell user data. It does not share your vocabulary or webpage content with
any third party for commercial purposes. The only outbound transmission is the data
required to fulfill a request you initiate: relevant text sent to the AI provider you
configured, or to the keyless translation endpoint when you use translation.
7. Analytics and Advertising
Vocab does not use webpage content or vocabulary data for advertising, and it does not
run analytics. The extension contains no telemetry, no crash reporting, and no
third-party tracking scripts, and it never shows or serves ads.
8. Browsing History
Vocab does not maintain a centralized browsing-history database. The extension reads
only the information required for its vocabulary functionality: the text of the page
you are on (to highlight saved words) and the content you explicitly select. It does
not build a log of the pages you visit.
9. Data Security
Vocab keeps your data on your device and limits outbound transmission to the requests
you make. Communication with AI providers and translation endpoints happens over HTTPS.
Stored locally does not mean invulnerable. Data in IndexedDB and
chrome.storage.local is only as protected as your browser profile, and a
locally stored API key could be read by anyone with access to that profile. If you want
nothing to leave your machine, use a local model and keep your key out of Settings.
10. User Control
You control your data at every step:
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Remove saved vocabulary — delete any entry from your library, or
clear the whole library.
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Remove local extension data — uninstalling the extension from
chrome://extensions removes the extension's stored data with it.
-
Change or remove your AI configuration — edit or delete your API key
and provider settings at any time in Settings.
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Stop using AI enrichment — saving, highlighting, and keyless
translation work without any AI key; simply don't trigger AI features.
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Export your data — back up or transfer your vocabulary as versioned
JSON at any time.
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Disable highlighting — turn on-page highlighting off in Settings.
11. Third-Party Services
The AI providers supported by Vocab — OpenAI, OpenRouter, DeepSeek, Mistral, Groq,
Together, Google Gemini, Anthropic, LM Studio, Ollama, and any custom endpoint you
configure — are independent third-party services, as is the keyless translation
endpoint. Vocab is not operated by, affiliated with, or endorsed by these providers.
When you use them, their own terms of service and privacy policies apply; this policy
does not govern those services.
12. Changes to This Policy
We may update this policy when Vocab's data practices change — for example, if a
feature that transmits data differently is added. When we do, the "Last updated" date
at the top of this page will change. Continued use of the extension after changes take
effect means you accept the updated policy.
13. Contact
If you have questions about this policy or about how Vocab handles data, email
hungpt591@gmail.com, or open an issue on the
Vocab GitHub repository.
For more detail on how Vocab is built, see the
privacy note in the project's README.