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The complete user manual.

Every button, setting, and screen in the Classroom Captions extension and teacher dashboard — for teachers and students.

Version 2.19.1

Live Classroom Captions is a Chrome extension that turns a teacher’s speech into live on-screen captions and translates them in real time, so every student can follow the lesson in their own language on their own device. Teachers sign in with Google; students never need an account.

1. Quick facts

2. Getting started (teachers)

  1. Install “Live Classroom Captions” from the Chrome Web Store.
  2. Click the CC icon in the Chrome toolbar to open the popup.
  3. The first time, the popup asks Who is using this device? Tap I’m a teacher. (A student taps I’m a student and gets the student view straight away — students never sign in and never have an account; see §8.)
  4. Click Sign in with Google. Your 10-day free trial starts immediately.
  5. Tap the language pills for the translations your class needs.
  6. Open a normal webpage (slides, docs, anything) and click Start Captions. Allow the microphone when Chrome asks.
  7. First-time users see a welcome overlay (“Welcome! Three steps to live captions”) — pick languages, click Start Captions, share the join code. Click Got it to dismiss it permanently.

3. The extension popup (teacher view)

Open it by clicking the CC toolbar icon. The popup has two possible views: teacher (default) and student. This section covers the teacher view.

3.1 Header

3.2 Signing in and the account bar

3.2a Email preferences (the one-time card)

The first time you open the popup after signing in, a small One quick thing card appears with one checkbox — Email me product news (“Occasional — only when we add something you’d actually use in class. Untick and we’ll never send one.”) — ticked by default, and a Got it button.

Either way you still get service email — the messages you need to run your account, like a reminder before your trial ends, a notice when it ends, billing receipts, and replies to your support tickets. Those aren’t optional and don’t carry an unsubscribe link. We do not send SMS messages and we do not make marketing phone calls.

3.3 Start Captions / Stop Captions

The large red button starts and stops a captioning session.

3.4 Recognition mode toggle

Two segments: Basic Mode and AI Mode. Switching mid-session shows “Switching recognition…”; while idle, “AI Mode selected” / “Basic Mode selected”. A hint line beneath explains the current mode; if your coin balance can’t cover one minute, it warns: “You are out of AI Coins — tap ‘Buy coins’ above to keep using AI Mode.” See §6 for the full comparison.

3.5 Your class room (live panel)

Appears only while captions are running with Room Sharing enabled (Settings page), signed in, and a class code set. Shows:

3.6 Presets

Visible only once you’ve saved at least one preset. Tap a preset pill (e.g. “B2 Chemistry”) to select all of its languages at once — you’ll see “B2 Chemistry selected”. The preset matching your current selection is highlighted.

3.7 Languages

Tap language pills to toggle which translations are broadcast. Each pill has the color used for that language’s caption stripe. Defaults: Spanish, Vietnamese, French, German. Add or remove languages and change colors on the Settings page (134 available).

Your own teaching language is the first pill. English (or whichever language you teach in) can be selected like any other, which makes an English-only session possible: turn every translation off, leave English on, and your students get captions in your own words and nothing else. That’s what a Deaf or hard-of-hearing student in an English-speaking class needs, and it saves as a preset like any other selection. Nothing is translated for that pill — your words are passed through as spoken.

Save selection as preset… opens a name field (max 40 characters, Enter to save, limit 10 presets). Errors: “Give the preset a name first”, “Select at least one language first”, “Preset limit reached (10) — remove one in Settings first”. Saving over an existing name replaces its languages.

3.8 My classes (permanent join codes)

One class per period. Each class has a permanent short code (e.g. CHEM42) that stays valid all year — students save it once and reconnect automatically every time you go live.

Each class row has four controls:

Creating a class: type a name (e.g. “Period B2 Chemistry”), optionally check Conference mode (“an all-day event, not a class period — room stays open 24 hours; shown as ‘Event: name’”), then Create. A code picker appears with a suggested code built from your class name (confusing characters 0/O/1/I/L are never generated). Choose Use this code, Generate another, or type your own 4–8 letter/number code and hit Use. Taken codes prompt for another. On success: “Class created — code CHEM42”, and the new class becomes active.

3.9 Co-present (co-teaching, with host approval)

Co-presenting uses a dedicated co-presenter code — never a class code — and requires the host teacher’s approval before anything appears on screen.

As the host: your personal co-presenter code (looks like CP plus 6 characters) lives in the Co-present area, shown as dots so nobody can shoulder-read it off a projected screen — tap Reveal to see it (it hides again when you close the popup or tap Hide). Tap the code to copy it, or tap ↻ to get a new one (the old code stops working for new requests). Share it with co-teachers only. When someone requests to co-present you’ll see them listed with Approve and × (deny) buttons — and if you’re mid-lesson, an on-screen prompt appears on your presentation tab so you can approve without opening the popup. Approving is one-time: that co-teacher can join your classes until you remove them with × in the approved list.

As the co-presenter: enter the host’s co-presenter code and press Co-present. You’ll see “Waiting for [host] to approve…” (with a Cancel request button) until they accept; then “Approved by [host] — your next Start Captions joins their class once it’s live.” Your captions appear to their students tagged with your name (“Ms. G: …”). Stop co-presenting returns captions to your own room.

Students can never co-present: knowing a class code grants reading only, and co-presenting requires both a teacher account and the host’s explicit approval, enforced by the server.

3.10 Caption options

3.12 I’m a student — join a class

The link at the bottom switches the popup to the student view (§8).

A device that answered I’m a student to the first-run question stays a student device: the sign-in card never appears on it again, and if a class closes the popup goes straight back to the student view. A teacher who tapped the wrong button can switch from the bottom of the student view (“Set up for a teacher instead”), as long as no class is joined. Either way, a student can never create an account: a school-issued student address is refused at sign-in.

4. The recognizer tab (while captioning)

Starting captions opens a pinned tab titled “🎙 Captions Running — keep this tab open”. This tab holds the microphone; you can switch to any other tab and captions follow you there.

5. Captions on screen (teacher)

5.1 Caption boxes

Each selected language gets its own floating box that works on any page:

5.2 Floating buttons (presentation tab only)

Five draggable round buttons appear while captioning:

The floating buttons also can’t overlap each other or the annotation toolbar — whichever one you just placed stays put and the others make room.

5.3 Annotating on screen (draw over any page)

The pen button appears automatically with the other floating buttons while you’re captioning — and, no captions needed, it also appears whenever you open the popup on a normal webpage, because Annotate this page (§3.10) is on by default. The toolbar stays tucked away until you tap the pen, so annotation is always one tap away without ever getting in your way. (Prefer it off? Uncheck the box once and it stays off.)

Tapping the pen shows and hides the toolbar — a slim light strip that appears centered at the bottom of the screen (drag any empty spot on the strip to move it; it returns to bottom-center each new session). The pen button itself stays on screen and draggable the whole time, and hiding the toolbar normally leaves your marks visible (there’s a Settings option to clear them instead — §9.4). To remove annotation from the page completely, uncheck Annotate this page in the popup.

While the pointer is over the page in Draw mode you get a stylus cursor (a hand when hovering anything you could pick up with Select); the eraser shows its red circle.

What makes it different from a whiteboard app: ink is anchored to the content, not the glass. Marks on a Google Doc or a Word document scroll with the document, survive zoom changes and window resizes, and in Google Slides, PowerPoint, and Canva each slide keeps its own ink — leave a slide and come back and your marks return.

Canva presentations work the same way as Google Slides: draw while editing or while presenting (full screen included), and each slide keeps its own marks. Your keyboard arrows, a presentation clicker, and the toolbar’s ◀ ▶ buttons all change slides while you stay in Draw mode.

Microsoft Word and PowerPoint on the web work too, opened from Office.com, OneDrive, SharePoint, or a file link in Teams. In Word, ink anchors to the page and scrolls with the document exactly as it does in Google Docs. In PowerPoint, draw while editing or during a Slide Show, and each slide keeps its own marks; your keyboard, a clicker, the scroll wheel, and the toolbar’s ◀ ▶ buttons all change slides without leaving Draw mode.

PDFs opened from Google Drive anchor per page, the same way a Google Doc does: mark up page 1, scroll to page 4 and mark that, scroll back, and each page still has its own ink. Zooming is fine too. This applies to a PDF opened from Drive (the address looks like drive.google.com/file/d/…/view). A PDF opened as a bare file link instead — an address ending in .pdf — is drawn by Chrome’s own built-in viewer, which no extension can see into: the pen still works there, but the marks stay where you put them on screen rather than following the page when you scroll.

The pen follows you. Annotation is per-teacher, not per-page, so once it’s on the round pen button appears on every page you open — jump from a deck to a Doc to a PDF and it’s already there, no reopening the popup and no reloading. Unchecking “Annotate this page” in the popup turns it off everywhere.

Presenting in Google Slides: everything works in present mode, fullscreen included — the pen, the toolbar, and your caption boxes all stay on screen. You never have to leave Draw mode to change slides:

Each slide keeps its own ink through all of it — go back a slide and your marks for that slide return.

The toolbar, left to right:

The board has no edges (v2.48.0). Put two fingers on it and drag to slide the board around; pinch to zoom in or out about your fingers. On a trackpad, two-finger scroll slides the board and ctrl/⌘ + scroll (or a trackpad pinch) zooms at the pointer. Everything on the board — ink, shapes, stickers, pictures — moves and zooms together (line widths included); widgets like timers stay put on the glass. Whenever the board is off 100% a small “72%” badge sits at the bottom-left: tap it to jump back to 100% at the starting spot. Where you left the board is remembered per document for the session.

5.4 Shapes, graphs, rulers, and protractors

Select (lasso icon, v2.48.0) sits on the MAIN toolbar row, just before the trash can, so it’s always one tap away — tap any shape, overlay, or piece of INK to select it; tap MORE items to add them to the selection (that’s how you build a group); tap empty space to clear. Or circle it: drag a loop around part of a drawing on empty space and everything inside the loop is selected (a stroke counts when at least half of it is inside). With more than one thing selected, each piece gets its own dotted box. Press a piece and drag and it becomes its own thing: the rest of the selection lets go, nothing is drawn round it while it moves, and it lands on its own — so a lassoed Bohr model can be rearranged electron by electron, each one carried freely from one atom to the next. To move several as one, Group them from the ⋮ menu first; a grouped selection travels together.

Record a motion (v2.50.0). While anything is playing, a red Stop button appears on the main toolbar row right after Select (v2.52.0) — one tap halts every moving piece; it disappears again when nothing is moving. Select a piece (an electron, say), open its ⋮ menu and tap Record motion. Now drag the piece the way you want it to travel — over to the other atom, around the nucleus, anywhere — and the moment you lift your finger the recording stops (a note in the toolbar tells you it’s armed, recording, and done). A small pill appears beside the trash can whenever that piece is selected: ▶ plays the motion once — the piece jumps back to where the drag began and travels the same path at the same speed — and while it’s moving that same button is ■ (stop); the loop repeats it until you stop it, and ✕ forgets the recording. Tapping a moving piece selects it (so the pill with ■ appears); dragging a moving piece stops it. A motion belongs to the piece, not to a spot on the page: move the piece — on its own or as part of a group — and it plays the same path from its new position. Play several at once (v2.58.0): lasso or tap-select any pieces that carry motions and the pill’s ▶ (or ⋮ → Play motion (n)) starts every selected one together — only those; pieces with motions outside the selection stay put. The loop, ■ and ✕ act on the same set. The toolbar’s red Stop still halts everything. The same choices are in the ⋮ menu (Play motion, Repeat motion, Stop, Forget motion, Record motion again). Nothing is drawn round the piece while it moves, and the board stays live: keep writing, erasing, adding shapes; pressing a moving piece stops it. Record a whole group and it travels together. Recordings are kept with the ink, so they’re there after a reload. Drag a corner handle of the outer outline to resize the whole selection (lines and arrows get endpoint handles instead). A padlock appears over locked selections. Because ink is selectable too, you can draw on a coordinate grid, select the grid and your drawings together, group them, and move the whole thing as one.

Tap the toolbar’s ▸ arrow to expand it for the shapes:

Two colours on one shape (v2.52.0): a toolbar preset recolours a selected shape’s outline and fill together, as before. To colour them separately, tap the outline swatch or the fill swatch in the properties row — a strip of your six presets opens, and the one you pick goes to that part only (picking a fill colour also turns the fill on). A black-outlined sphere with a green inside is two taps.

While anything is selected, a properties row appears in the panel:

Auto-detect (off by default): with a switch on — in the toolbar’s Smart row (gear), or in Settings & styling → Annotation — a pen stroke that looks like a straight line, circle, square, or triangle is replaced with the clean shape the moment you lift your finger, in your current pen color. Triangles are classified as you drew them: something close to a right, isosceles, or equilateral triangle snaps to the exact kind, and anything else stays the scalene triangle you made. Off means your ink is never changed.

Squares are deliberately hard to trigger: the stroke has to hug its own bounding box and turn at its corners before it counts as one. Handwriting doesn’t, so a letter written next to a diagram stays a letter.

Worth knowing:

6. Basic Mode vs AI Mode

Basic Mode AI Mode
Cost Free, unlimited 4 AI Coins per minute of listening
Engine Browser speech recognition AI-powered recognition
Accuracy Fine for everyday speech Far better with technical/scientific vocabulary
Student answers in another language Tap the person icon and pick the language Detected automatically — no tapping
Non-English teaching Less reliable Recommended
Captions arrive Word by word In full sentences, on natural pauses
Silence — Charging auto-pauses; quiet minutes are free

When coins run out, AI Mode stops with a clear message and you can keep teaching free in Basic Mode. You can never be charged beyond the coins you chose to buy. No AI account or API key is ever needed.

7. Sharing captions with students (Room Sharing)

  1. Turn on Enable Room Sharing on the Settings page (off by default).
  2. Create a class in the popup’s My classes and make it active.
  3. Share the code: paste the class link into Google Classroom/Canvas, show the QR, or just tell students the short code (codes are not case-sensitive).
  4. Start Captions. Students who saved your code press Start on your class in their extension (§8.2) and connect for that session.

Captions are opt-in on the student side: a saved code alone never shows captions — each session the student presses Start, and when you press Stop Captions every connected student’s session ends too (they press Start again next class). Only caption text is relayed — never audio, never student identity. A normal class session’s room stays open up to 8 hours; conference/event classes stay open 24 hours. Shared captions are deleted from our servers within 24 hours.

8. Student guide

Students install the same extension. No account, ever.

8.1 Joining

Click the CC icon → I’m a student — join a class → paste the join code from Classroom/Canvas, or type the short class code (e.g. CHEM42), then Add. You only do this once per class — joining SAVES the class; it does not show captions by itself. Add as many classes as you have teachers; tap a class name to switch, or × to remove one.

8.2 Starting and reading captions

Captions are opt-in, one class at a time:

8.3 Asking your teacher a question

Two ways to ask — both reach the teacher the same way:

The teacher sees your question translated into their language. Sending has a 20-second cooldown; after 5 questions you’ll be asked to “Give others a chance” for a couple of minutes. If your teacher isn’t captioning right now, the popup tells you: “Your teacher isn’t live right now — try again once captions start.”

9. Settings page (“Settings & styling”)

Reached from the popup. Except where noted, changes apply only after clicking Save settings at the bottom.

9.1 Speech Recognition

9.2 Room Sharing

9.3 Content Filter

9.4 Annotation

Smart-input switches for the on-screen annotation pen. Four auto-detect switches (all off by default): Straighten lines automatically, Turn round scribbles into circles, Turn boxy scribbles into squares, and Turn three-cornered scribbles into triangles (classified as right, isosceles, equilateral, or scalene) — off means your ink is never changed. Plus the Palm eraser (on by default): on a touch screen, wiping with your open palm erases the ink underneath. The same five switches live in the annotation toolbar’s Smart row (gear icon); either place applies instantly, no Save needed.

Also here: Clear the screen when the toolbar is hidden (off by default). On, hiding the annotation toolbar (pen button or its ✕) also removes all ink and shapes; off, hiding leaves your marks on screen. Either way a cleared screen is undoable — reopen the toolbar and tap Undo.

9.5 Privacy

Share anonymous usage and error reports (on by default). Helps us fix bugs and see which features earn their keep. Reports never include caption text, transcripts, class codes, student information, or the pages you visit — just feature names, counts, and crash details tied to a random device ID (not your account). Turning it off takes effect immediately. Details: classroomcaptions.com/privacy.html.

9.6 Live Preview & Caption Bar Appearance

A live preview shows your styling as you adjust: background Black/White, opacity (0–1), font size (14–60px), font color. Reset all caption box positions fixes boxes that drifted off-screen (instant, no Save).

9.7 Quick-Pick Languages

The list behind the popup’s language pills. Each row: label (editable), code, stripe color, and × to remove. The top row is your own language (“always shown”) — only its stripe color is editable. + Add language opens a picker of 134 languages with an editable display label and stripe color. Duplicates are rejected (“That language is already in your list”).

9.8 Presets

Create named language groups (“+ Add preset” → name it → tap language chips). Your own teaching language is the first chip, so an English-only preset is possible. Presets with blank names are discarded on Save. Delete with ×.

9.9 Delete my account

Type DELETE and press Delete my account — cancels any subscription first, then permanently deletes your profile, coins, classes, and rooms. Transcripts in your Google Drive are untouched. Cannot be undone. (Also available on the teacher dashboard, §12.)

9.10 Save / Reset

Save settings persists everything and restyles captions on open pages immediately. Reset to defaults (with confirmation) restores original styling and the four default languages; it does not touch recognition mode, your language, Room Sharing, the content filter, vocabulary, or transcripts.

10. Vocabulary page (“User added vocabulary”)

Control the translations of technical terms yourself instead of letting the automatic translator guess. When a term is recognized correctly in your captions, your manual translation is used in its place.

11. Transcripts page (“Class transcripts”)

Every captioning session is recorded automatically while “Record transcripts” is on (popup checkbox). Sessions are listed with date, length, and entry count; Open shows the full timestamped transcript with every translation.

12. Teacher dashboard (www.classroomcaptions.com/dashboard.html)

Sign in with the same Google account you use in the extension.

13. Billing summary

14. Troubleshooting

Nothing happens / no captions appear — check the microphone first

Almost every report of “it isn’t working”, “no captions”, “nothing happens”, or “it can’t hear me” turns out to be one of two microphone problems. Check both before anything else. There is a step-by-step version of this with a screenshot at classroomcaptions.com/troubleshooting.html.

1. Is a microphone connected at all? Classroom Captions listens to you speak and turns that into text, so with no microphone connected to the computer it cannot produce captions — there is nothing for it to hear, and no setting works around it. Most laptops have one built in; many desktop computers and classroom podium PCs do not, and an external microphone or headset has to be plugged in AND selected as the input device. Check this before starting a trial or subscribing, especially on a desktop. Quick test: open the computer’s sound settings, find the input/recording section, and speak — if the input meter moves, the microphone works.

2. Is microphone access switched on for the captions tab? Pressing Start Captions opens a small pinned tab that does the listening; its address starts with chrome-extension:// and ends in recognizer.html. Captions appear on the page you teach from, but the microphone belongs to that pinned tab. Switch to it and look at the LEFT end of the address bar:

Still nothing? Another app may be holding the microphone exclusively (Zoom, Teams, Meet, recording software) — close it and press Try again. If a headset was unplugged mid-session the computer may have switched to an input that isn’t there. And don’t close the pinned captions tab: that ends the session.

Everything else

15. Privacy at a glance

Teachers sign in with Google; we store the account email and billing status. Students have no accounts — a student device is known only by a random identifier used to count “N students joined”. Captions appear on a student device only after the student presses Start for that class, and every session ends when the teacher stops captioning — a saved class code never listens in on its own. The extension never records or stores audio: in Basic Mode, Chrome’s own speech service handles it (the same Google-run service behind voice typing in Chrome) and only the text reaches the extension; in AI Mode audio is streamed securely to OpenAI for transcription and never stored. Shared caption text, questions, and presence data are deleted within 24 hours (full retention table in §15.1). Transcripts belong to the teacher, in the teacher’s own Google Drive. Payments are handled entirely by Stripe. The extension sends anonymous crash reports and feature-usage counts (never caption text, class codes, student information, or the pages you visit) — turn this off any time in Settings → Privacy. We send service email you can’t opt out of (trial reminders, receipts, support replies) and optional product news you can, from the dashboard’s Email preferences switch or the unsubscribe link in any such email; we never send SMS or marketing calls, and we never sell or rent your address. We also keep a copy of the Terms and Privacy Policy as they read on the day you agreed to them. Full policy: classroomcaptions.com/privacy.html.

15.1 How long we keep things

Every piece of data the Service touches, and how long it survives. If an administrator asks “what do you keep and for how long,” this is the whole answer.

What How long we keep it Where it lives
Your audio Never recorded or stored by us. In Basic Mode, Chrome’s built-in speech service (run by Google, the same one behind voice typing) handles it and only the text reaches the extension. In AI Mode it is streamed to OpenAI for transcription and discarded as it goes. Nowhere
Shared caption text (what students read on their devices) 24 hours, then deleted automatically Our database
Student questions 24 hours, then deleted automatically Our database
Presence heartbeats (the “N students joined” count) 24 hours, then deleted automatically Our database
Live rooms Close automatically about 8 hours after they open; conference/event classes stay open 24 hours. Closing a room ends every student session. Our database
Translated phrases 30 days. See the note below — this is the one item that outlives a class period. Our database
Parent share links 7 days, then the link stops working and the snapshot is deleted Our database
Your transcripts Kept until you delete them. They are Google Docs in your own Drive; we never hold a copy and deleting your account doesn’t touch them. Your Google Drive
Your account (email, plan, coin ledger, classes, saved codes) Until you delete your account. Deletion cancels your subscription first, then removes everything attached to your profile in one cascade. Our database
Caption-session records (when each session started and stopped, Basic or AI, how many languages, whether a room was open, caption count — never the words) and the monthly count of characters translated Until you delete your account (same cascade). Visible only to you, on your dashboard. Our database
Quick Add links (up to five website names + addresses you save in the embed widget) Until you delete them in the widget or delete your account. Our database
Payment details Held by Stripe under its own policy. We never see or store a card number. Stripe
Sign-up signals (the IP address and country you signed up from, a random install identifier, and — if you add a card — whether Stripe has seen that card on another account, its type, and its issuing country; never the card number) Until you delete your account. Used only to keep free trials to one per teacher. Our database
Support tickets and replies Kept while your account exists, so we can follow up on a conversation. The text is processed by Anthropic to sort and draft a reply. Our database
Crash and usage reports Anonymous, tied to a random device ID and never to you. Turn them off entirely in Settings → Privacy. Sentry, PostHog
Security audit entries (a record that a purchase or sign-in happened) Kept for operational security Our database

About the translation cache. Translating the same sentence twice costs money for no benefit, so when a phrase is translated it is kept alongside its translations and reused — including for other teachers, which is why common classroom phrases translate instantly. Three things are worth knowing about it:

If you would rather nothing you say contributes to it, Basic Mode without any translation languages selected never writes to it at all.

Questions this manual doesn’t answer: email support@classroomcaptions.com or use the Contact support form on the teacher dashboard — you’ll get a reference number and a reply by email.