Click ▣ Capture content and pick your slides, whiteboard, or iPad window.
Window 2
No second window yet
Click ▣ Capture 2nd window and pick another window (e.g. a desktop app).
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Numberbender Studio — quick start
Make a clean layout of your camera and your content, then share it into Zoom or Teams. No install — it all runs in this browser.
Pick a layout
▥ Side-by-side — camera and one content window next to each other. Drag the divider to resize, ⇄ Flip to swap sides.
▣ Spotlight — your content fills the screen with your camera as a small bubble in the corner. Great for talking over slides.
⊞ Dual + cam — two captured windows side by side (e.g. your iPad whiteboard + a desktop app) with your camera as a corner bubble on top, so you stay visible while you teach.
1. Allow your camera
Click Allow when the browser asks. Pick the right camera from the dropdown if you have more than one.
Optional — use your phone as your camera
Any phone your computer sees as a camera shows up in the camera dropdown — connect it, then pick it. All wireless:
iPhone + Mac: use Continuity Camera, built into macOS & iOS — same Apple ID, Wi-Fi and Bluetooth on, and your iPhone appears as a camera. Nothing to install.
Android + Windows: recent Windows 11 can use your phone through the Phone Link app as a connected camera.
Any phone, any computer: install a webcam app like Iriun, DroidCam, or Camo (iPhone or Android, Mac or Windows) — open it on the phone and on the computer, and the phone shows up as a camera here.
Connected the phone after opening Studio? The dropdown refreshes on its own — just click it and choose your phone.
2. Capture your content
Click ▣ Capture content and choose the window for the content side. In Dual + cam, click ▣ Capture 2nd window to add a second window.
iPad (Mac): connect via cable → open QuickTime Player → File ▸ New Movie Recording → click the ⌄ next to record → choose your iPad. Then pick that QuickTime window here.
iPad (Windows): run an AirPlay-receiver app (e.g. 5KPlayer, ApowerMirror), mirror your iPad to it, then pick that window here.
Wacom / Bamboo pad: it has no screen of its own — open any whiteboard app and capture that app's window.
3. Arrange & position the camera bubble
In Spotlight and Dual layouts, set the camera bubble's corner, shape (circle or square), and size from the toolbar. Mirror cam gives a selfie-style view.
4. Go live in Zoom / Teams
Click ◧ Presenter (hides these controls) or ⤢ Fullscreen.
In Zoom/Teams choose Share Screen.
Pick this browser tab (cleanest) — or this window if you went fullscreen.
Tip: capture a single window (not your whole screen) so you don't get a mirror-in-mirror loop. The “Powered by Numberbender” badge stays in the shared view. Press Esc to leave fullscreen/presenter.
🔴 Record a lesson (prototype)
This test build can record your stage straight to a video file — nothing is uploaded and nothing touches a server. The video stays on your computer until you choose to post it to YouTube.
Set up your scene (camera + content). For the sharpest result, click ⤢ Fullscreen first.
Choose your file type in the Save: menu next to Record — Auto (recommended), MP4, or WebM.
Click 🔴 Record. If the browser asks what to share, choose This Tab and click Share; allow the microphone when asked.
On Chrome/Edge you'll pick where to save — it then records straight to disk (so even long lectures won't fill up memory).
Click ■ Stop (top bar or the floating pill) when finished, then upload the file straight to YouTube.
Which file type should I pick?
MP4 — recommended. The universal format: plays everywhere and opens in any editor (iMovie, Premiere, CapCut, DaVinci, Final Cut). Pick this if you might trim or edit before posting.
WebM. A free, open format. It uploads to YouTube perfectly — YouTube lists WebM as a supported format and re-encodes every upload anyway, so your students see no difference. The catch: most desktop editors can't open WebM, so it's best when you'll upload as-is without editing.
Auto. Saves MP4 when your browser can, and quietly falls back to WebM if it can't. Either way you get a working, uploadable file.
If you asked for MP4 but got WebM: your browser can't record MP4 (common on Firefox, Safari, and phones). The WebM file is still perfectly fine to upload to YouTube — you just won't be able to edit it in most software first. For a guaranteed MP4, record in Chrome or Edge on a computer.
Best in Chrome or Edge on a computer. Safari and phones have limited recording support — Studio will tell you if yours can't record. Recording uses your processor, so for long lectures it's smoother to record on its own rather than while you're also live in Zoom.
What each control does
Controls are colour-coded by job: teal = set up your scene, purple = adjust the look, orange = go live.
Layout switcher — pick Side-by-side, Spotlight, or Dual + cam.
▣ Capture content — choose the window for the main content. Click again anytime to switch windows.
▣ Capture 2nd window (Dual only) — choose a second window to show beside the first.
Camera dropdown — pick which camera feeds the camera view: built-in, an external webcam, or your phone.
⇄ Flip — swap which side each window sits on.
Mirror cam — flips your camera left-to-right for a selfie view; it does not change your content.
Cam corner / shape / size — position, shape, and size of the camera bubble in Spotlight and Dual layouts.
Drag a divider — make the side-by-side panes wider or narrower.
★ Replace logo — swap the badge logo for your own image; it is remembered next time.
Badge position — move the “Powered by Numberbender” badge to any corner.
◧ Presenter — hides all controls for a clean broadcast. A reminder bar appears at the top; press Esc or click it to bring the menu back.
⤢ Fullscreen — expands the layout to fill your screen (Esc to exit).
? Help — opens this guide.
Studio remembers your layout, sizes, camera-bubble settings, badge position, and logo for next time. Audio stays in Zoom/Teams as usual — Studio only handles the picture.