highl8teComing soonExplain any word you highlight.
Select text, read a plain explanation, carry on. Nothing leaves your machine.
Free · No account needed
Four steps. That's it.
Add it to Chrome
highl8te needs Chrome 138 or newer. It starts working on any tab you reload after installing — nothing to configure, nothing to sign into.
Select some text
Highlight a word or a sentence and the popup opens next to it. Prefer a shortcut? Press Alt+Shift+E. Prefer a menu? Right-click the selection.
Read the answer
Words come back instantly from the bundled dictionary. Longer selections stream in from the on-device model a few words at a time.
Switch modes if it did not land
Flip the pill toggle between Technical and ELI5 on the same selection until the explanation clicks. Then close it and keep reading.
Nothing to send, nowhere to send it.
Most tools that explain text ship your selection to a server and then promise to behave once it arrives. highl8te has no server to ship it to. The dictionary is inside the extension package and the model is inside your browser, so your text never reaches a network at all.
Chrome downloads Gemini Nano once, roughly 2 GB, as a browser feature on its own schedule. That download is Chrome's, not ours — the dictionary works the whole time it runs.
Everything in the box.
Two engines sit behind that popup, and highl8te picks between them for you. Single words and short phrases go to a dictionary that ships inside the extension — Open English WordNet 2025, stored as local JSON shards that are already on your disk. That lookup is a file read, so it is instant, and it resolves base forms: "grabbed" lands on "grab", "men" lands on "man". You get part-of-speech tags, definitions, and usage examples. Anything longer goes to Gemini Nano, the AI model built into Chrome, through the Prompt API. It streams the answer in a few sentences at a time and reads only the surrounding paragraph, which is how it tells a river bank from the kind with a vault. Two modes share one toggle: Technical keeps the real terminology, ELI5 trades it for a comparison a child would follow.
There is no server here. highl8te makes zero network requests, because the dictionary is bundled and the model runs inside your own browser. No account, no API key, no telemetry — that is the architecture, not a policy we are asking you to trust. It is also free, permanently: no tiers, no quota, no Pro edition, no trial that runs out. If it saves you enough trips to the search bar to feel like saying thanks, there is one optional tip jar at https://buymemomo.com/aarohan. Nothing in the extension is behind it.
Honest about the edges.
Works with
- Any web page you can select text on — articles, docs, forums, email
- Single words and short phrases, answered from the bundled dictionary
- Phrases, full sentences, and jargon, answered by the on-device model
- PDFs in Chrome’s built-in viewer, via right-click, answered in the side panel
- English text
Doesn't
- Firefox, Edge, Safari, and every mobile browser
- Chrome older than 138 — the built-in AI APIs are not there
- Languages other than English
- Scanned PDFs and images with no selectable text
- Pages Chrome blocks extensions from, such as chrome:// URLs and the Web Store
- Explanations come from a small AI model and can be confidently wrong — treat them as a first pass, not a source of truth
- Gemini Nano needs a one-time download of roughly 2 GB that Chrome schedules itself; until it lands, only the dictionary answers
- Some devices do not meet the hardware bar for the on-device model — highl8te says so plainly rather than spinning
- Auto-explain ignores selections longer than about 300 characters and stays silent in text fields you are typing in
- Inside PDFs the popup cannot be drawn on the page, so the right-click menu and side panel are the way in
- Dictionary coverage is whatever Open English WordNet 2025 contains — very new slang and proper nouns fall through to the model
◆ PRICE
Free. The whole thing.
No tiers, no quota, no trial — and no payment processing anywhere in the extension
- + Every feature, at no cost — there is no paid tier to upgrade to
- + No account, no sign-up, no API key
- + Bundled offline dictionary with definitions and examples
- + On-device AI explanations through Chrome
- + Technical and ELI5 modes
- + Right-click support inside Chrome's PDF viewer
- + No ads, no telemetry, no data collection
- + Optional tip jar if you feel like it — nothing is locked behind it