Guide

Quick start

1. Display PC (receiver)

On the computer connected to the projector or big screen, open the receiver. It shows a 9-digit cast ID, a short link for presenters, and a QR code. The ID is remembered on that computer, so it stays the same next time.

2. Your computer (presenter)

Open the short link shown on the display (for example lectocast.ayucode.com/c/123456789 — the ID is filled in for you), or go to Start casting and enter the 9-digit ID. You can also enter your name, which is shown on the display.

3. Choose what to share

Click "Choose a screen and cast". The browser asks whether to share an entire screen, a window, or a tab. Once you pick one, it appears on the display.

• Slides / Video: Slides mode keeps small text sharp; switch to Video mode for smooth playback.
• Switch screen: share a different window or screen without stopping the cast.
• Pause: the display shows a black screen for a moment — handy when switching to private content.
• Stop casting: click Stop, or use the browser’s "Stop sharing" bar.

Connection modes: preventing unwanted casts

Choose a connection mode in the receiver’s Settings (bottom-right corner):

• The PIN changes after every cast. Five wrong attempts lock it for 60 seconds and generate a new PIN.
• Requests in ask-to-accept mode are declined automatically after 30 seconds without a response.
• Switching to a mode that requires verification during a cast stops the current cast; the presenter must verify again.

Install as an app (optional)

The website can be installed as an app: it opens in its own window without the address bar and launches from your desktop, Start menu, or Dock. Every feature also works without installing.

• Chrome / Edge (desktop): click "Install app" in the header or the install icon in the address bar. On the receiver, you can also use Settings → Install as an app.
• Safari (macOS): choose File → Add to Dock.
• iPhone / iPad: tap Share → Add to Home Screen (mobile devices can only be receivers).
• The app remembers whether you last used the presenter or the receiver and opens it directly. Right-click the app icon to choose either one.

Automatic updates

• When a new version is available, the page shows "A new version is available" — click "Update now".
• A waiting receiver updates automatically after a 10-second countdown, which suits displays without a keyboard or mouse. It never updates during a cast; it waits until the cast ends.
• Open pages check for a new version every hour and whenever you return to the tab.

Auto-start on boot (displays without keyboard or mouse)

Every receiver setting can go in the URL. Have the display PC open that URL at boot and no interaction is needed. Even if browser data is wiped (for example by a restore card), the cast ID stays the same.

In the receiver, Settings → Startup URL copies the URL for the current settings.

Windows: create a startup shortcut

1. Press Win + R, type shell:startup, and press Enter to open the Startup folder.
2. Right-click in the folder → New → Shortcut.
3. Paste one of the lines below as the target (replace the URL with your startup URL), then restart to test.

"C:\Program Files\Google\Chrome\Application\chrome.exe" --kiosk --autoplay-policy=no-user-gesture-required "https://lectocast.ayucode.com/player?id=123456789&mode=pin&lang=en"

"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --kiosk --edge-kiosk-type=fullscreen --autoplay-policy=no-user-gesture-required --no-first-run "https://lectocast.ayucode.com/player?id=123456789&mode=pin&lang=en"

• --kiosk: opens full screen without the address bar. A web page cannot enter full screen on its own without user interaction, so this flag is needed.
• --autoplay-policy=no-user-gesture-required: allows sound to play without anyone clicking. Without it, video starts muted and shows "Click to turn on sound".
• Press Alt + F4 to exit kiosk mode.

Sharing sound

• Chrome / Edge: when sharing a tab, check "Also share tab audio"; on Windows, when sharing an entire screen, check "Also share system audio".
• Firefox / Safari: cannot share audio yet. Use Chrome or Edge if you need sound.
• If the receiver shows "Click to turn on sound", that is the browser’s autoplay rule — just click it. For unattended displays, see the startup flags above.
• The preview on the presenter’s side is always muted to avoid echo from playing the same audio twice.

Troubleshooting

"No display found with this ID"

• Check that the ID is correct and the receiver page is still open on the display PC (yellow or green light in the status bar).
• Once the receiver is open, casting starts automatically — no need to enter the ID again.

Stuck on "Setting up the picture" or the connection fails

• Some campus, corporate, or public Wi-Fi networks block peer-to-peer connections. Try connecting both computers to the same network, or use a phone hotspot.
• If your work computer uses a firewall or VPN, temporarily turn off the VPN and try again.

Blurry text

• Switch the content type to "Slides" on the presenter side.
• On a 4K screen, share a single window instead of the entire screen.
• Quality drops automatically on slow networks; a wired connection gives a sharper picture.

Lag or stutter

• Switch the content type to "Video" when playing videos.
• Close unneeded tabs and downloads, or use a wired connection.

"This cast ID is open somewhere else"

A cast ID can be used in only one tab or on one computer at a time. When it is opened elsewhere, the old page stops; click "Use it here instead" to switch back.

Browser support

Want to cast with the Chrome extension? See the extension page.