Privacy
Last updated 29 September 2026.
Explayn explains things you highlight, frame or open — in Chrome, on a Mac, on Windows and on an iPad. To do that it has to send what you asked about somewhere. This page says exactly what leaves your device, when, where it goes, and what survives the round trip — which is almost nothing.
What is sent, and only when you ask
Nothing leaves the page until you click Explain, press the keyboard shortcut, or use the right-click menu. Highlighting text on its own sends nothing; the button that appears is drawn locally by the extension.
When you do ask, the request contains:
The text you selected, and the block of text it sits inside — the paragraph or list item — because pronouns and acronyms cannot be explained without the sentence that introduced them. For a screenshot, the image you framed, cropped to your box and scaled down, plus any visible text around it. Also the page’s title and URL, your chosen explanation level, answer length and answer language, the few words you wrote under About you if you wrote any, and — if you set one — your provider key, as a request header. Notes you add to a chat stay on your device. In the Mac and Windows apps the page title is replaced by the name of the app you were in.
A question you type — into Ask Explayn, or as a follow-up — is sent with the thread it belongs to (the last few questions and answers), so the answer can follow on.
A file you open with Explayn — a PDF, a Word document, slides or a spreadsheet — is read on your own device, and the text taken from it (up to about 40,000 characters) is sent to be explained. A scanned file with no text in it is sent as a picture of its first page. The file itself is never uploaded.
Reading aloud
Explayn can read a passage to you and light up each word as it is spoken. There are two voices behind that and they differ in exactly the way that matters here.
Your own device’s voices speak entirely on your machine. Nothing is sent anywhere, and a reading works with no network at all. Their word timing is estimated from a model of how long each word takes to say.
The neural voices are synthesised by Explayn’s endpoint, which means the sentences being read are sent to it, one at a time, and come back as audio carrying the exact moment each word is spoken — which is why the highlight lands precisely rather than approximately. The endpoint synthesises it on Microsoft’s Edge voices, and if that fails passes the sentence to a backup voice service Explayn runs, which does the same; nothing about the reading is stored by Explayn, and the request carries no key and nothing identifying you. Which of the two speaks is a setting, and choosing a device voice is how you read with nothing leaving your machine.
Having a photographed passage read aloud — a scan, a slide, a figure — sends that image to the endpoint to be transcribed first, the same way an explanation of a picture does.
Where it goes
To Explayn’s endpoint, which forwards it to a language model provider and streams the answer straight back to the card. Depending on which key is in play, that provider is Google, Groq, Cerebras, OpenRouter, Mistral, Anthropic, or Vercel’s AI Gateway. They each have their own terms and their own retention; Explayn picks the provider, not their policy. If you choose On this machine in the extension’s Options, or On this Mac / On this computer in the Mac and Windows apps’ settings, Explayn talks to Ollama or LM Studio on localhost and the endpoint is not involved at all — nothing you highlight or frame leaves your computer.
What Explayn keeps
Not the text, and not the pictures. The endpoint holds the request in memory long enough to stream an answer through it and keeps no copy — there is no database of what anybody highlighted, because there is no table for it.
Each request writes one line to the server log: whether it was text or an image, how many milliseconds it took, which providers were tried, and how each one answered. No selection, no image, no URL. Those lines exist so that “why was that slow” is answerable, and they age out with the platform’s own log retention.
To keep the free shared key and the voices from being drained by scripts, the endpoint keeps a count of requests against your IP address for each ten-minute window, in Explayn’s database. It is a number and nothing else — not associated with anything you sent — and it is deleted after a day.
Crash and error reports. When Explayn itself breaks — the Mac or Windows app crashes, a shortcut can’t be registered, or code inside the extension throws an error — it sends a short report so the fault can be fixed: what went wrong, where in Explayn’s own code, the versions of Explayn and your operating system, and a random ID made for that copy of Explayn (not tied to you, your account or your Mac). Never your highlight, the page, a screenshot or anything you typed, and file paths are cut down so your user name is not in them. If a report arrives without that random ID, a one-way hash of the IP address stands in for it. Reports are stored in Explayn’s database so repeats can be counted, and deleted after 90 days. Turn them off in the Mac or Windows app’s Settings or the extension’s Settings → Advanced.
Update checks. The Mac and Windows apps ask explayn.com.au/api/version once a day whether a newer Explayn is out. The request carries nothing about you or your copy beyond what any web request carries, and nothing about it is kept.
What stays in your browser
Your settings — explanation level, language, what a highlight does, disabled sites, and any keys you enter — live on your own machine: in chrome.storage.local for the extension, and in the app’s own settings on a Mac or Windows PC.
Your recent chats are kept the same way, on your own device and nowhere else, so you can read them again, carry one on or be tested on it: the last sixty in Chrome (with what each was about, including the words of a file you opened, and a small picture of a screenshot), in Explayn’s own folder on a Mac, in the app on Windows, and the last forty in the iPad and iPhone app — with when each was reviewed, for Review’s schedule, and in Chrome a short list of the words each page’s chats were about, for marking them when you come back. Explayn never uploads them; a chat you carry on sends its conversation again only to answer your next question, as it did the first time. In Chrome you can stop keeping them or clear them under Options → Your chats; on a Mac and on Windows, Clear is under Recent. Where you were in a PDF is kept the same way. Uninstalling the extension or the app removes all of it. There are no cookies and no analytics on the extension, and no third-party trackers on this site.
Deleting things
Nothing described here is kept against your name: it either was never stored or is on your own machine, where you can clear it by removing the extension or the app. Anything else — a crash report you want gone — email hello@explayn.com.au and it will be deleted.
Where your information is handled
Explayn is run from Australia and handles personal information in line with the Australian Privacy Principles. The services it relies on are overseas: the website and endpoint run on Vercel, the database on Neon, and answers come from the model providers named above — mostly in the United States. Sending a request to them is how Explayn works, so using it means your requests are handled there, under those providers’ terms.
If you think Explayn has mishandled your information, email hello@explayn.com.au first. If that doesn’t resolve it, you can complain to the Office of the Australian Information Commissioner at oaic.gov.au.
Children
Explayn is not directed at children under 13 and no account is knowingly created for one.
Changes
If what Explayn sends or keeps ever changes, this page changes with it and the date at the top moves. A change that means Explayn keeps something it did not keep before will be said plainly here rather than folded into a paragraph.