User Guide for BigBlueButton
Updated automatically every 5 minutes

User Guide for BigBlueButton

Last updated: 2018-05-25

BigBlueButton is a web-based application that enables you to participate in an online class or session.

Tutorial Videos

Minimum Requirements (for Students/Viewers)

Minimum Requirements (for Moderators/Presenters)


Why is my microphone not working?

How do I mute/unmute myself?

I got disconnected, how do I rejoin?

How do I share my desktop (presenter)?

Why am I receiving a “Cannot Connect to WebRTC” message?

Why can’t I save screenshare.jnlp in Chrome 65?

Tutorial Videos

The process to join audio is straightforward (choose either microphone or listen only).

If your microphone does not work, watch this short tutorial video on setting up and testing your microphone. 

This video will cover

  1. Types of headsets
  2. Connecting the headset to your computer
  3. Checking the headset’s microphone works (Mac OS X and Windows)
  4. Joining the audio in BigBlueButton

Once you’ve gotten your microphone working, there are two more tutorial videos to help you get started quickly.

For students/viewers, watch this short (< 5 minutes) tutorial video. 

While it didn’t win an Academy Award for Best Short Animated Film, it does give a concise overview of how to join the audio, adjust your microphone, raise your hand, mute/unmute yourself and chat.  If your not going to moderator or present, this video will get you going.

For instructors/moderators (or if you are going to be presenting), the following video will give you an overview for using BigBlueButton to present to students/viewers. 

Minimum Requirements (for Students/Viewers)

Most students today connect with a modern laptop (or desktop), use a modern browser (such as FireFox or Chrome) and have good internet.  In many cases, BigBlueButton will “just work”.

Here’s a more detailed breakdown on requirements:

1.  For computer, you need a laptop or desktop computer with (at least) 2G of memory and a 1Ghz processor (any computer bought in the last four years should be fine).  BigBlueButton does not run on a mobile or tablet (though we are working on a mobile client).

2.  For bandwidth, you must have at least 0.5 Mbits/second upstream and 1 Mbits/second downstream (check bandwidth using  Here’s a sample report from

3.  For browsers, we recommend Google Chrome (Flash is built-in) or Mozilla FireFox.  You can also use Internet Explorer and Safari, but you’ll get better audio using Chrome and FireFox via WebRTC.

4.  For audio, we strongly recommend using a headset.  A headset will ensure that others can hear your voice clearly and you don’t cause echo or background noise for others.  You do not need to buy an expensive one -- any basic headset with a built-in microphone will suffice.  

5.  If you have a firewall, let your network administrator know that the client (running with your browser) needs to connect to an external server on ports TCP/IP ports 80, 443, 1935 and UDP ports 16384-32768.  

A laptop with a built-in webcam and microphone will be sufficient as well if you’re in a quiet area.

Minimum Requirements (for Moderators/Presenters)

A moderator or presenter has the same requirements as students, with the following additions if you intend to screen share:

  1. You must have the latest Java plug-in installed (Java SE 8).  You can test with‎, and
  2. You must have a minimum recommended upstream bandwidth of 1 Mbits/sec

Desktop sharing uses more bandwidth than sharing a webcam, so a good upstream bandwidth is required (at least 1 Mbits/sec) .

Also, we recommend moderators or presenters connect through a wired network (not wireless) if possible.  If connecting from a wireless network, you may experience periodic disconnects or gaps in your audio.


Why is my microphone not working?

1. If you’re using Google Chrome, make sure you give the browser permission by clicking ‘Allow’ at the top right hand corner of the screen (in most cases).

Check if the camera icon in the right-hand corner of the URL has an ‘x’ through it.

If you see this icon, click it and give Chrome permission to access your webcam and microphone.

1.a. If you’re using Mozilla FireFox, make sure you give the browser permission by clicking “Share Selected Devices” at the top left hand side of the screen (in most cases).

Screen Shot 2014-10-03 at 1.42.17 PM.png

If you happen to click anywhere else on the screen before giving the browser permission, you can select the microphone icon found next to the web address in the navigation bar (see below).

Screen Shot 2014-10-03 at 1.42.37 PM.png

2.  Try switching between Google Chrome and Mozilla FireFox browser

3.  Check that your computer has a functioning microphone

The following video will show how to check that your microphone is generating audio (Mac OS X and Windows). 

The steps to check are given below.

On Windows, right-click on the speaker icon (lower right-hand corner of your screen) and choose Recording devices.

This will display a window showing your active microphones.

You need to see green bars move as you talk.  If you don’t, check if your microphone has a hardware mute button (it’s usually a button on the cord leading to the computer).

If the bars are very faint, you can increase the audio levels by clicking the microphone, then click the ‘Preferences’ button.  

You’ll see the Microphone Properties dialog. Click ‘Levels’ tab and increase the microphone sensitivity to about 75.

Click OK.  The green bars should now move higher when you talk.

On Mac OS X, open the System Preferences and click on the Sound icon.

As you talk, you need to see blue bars highlight on the Input Level.  Tap your microphone -- you should use see the blue energy bars move.  If not, select a different microphone from the list.

4. If you are using Safari and are being disconnected after adjusting your audio and are prompted with a “Plugin Error”, we recommend you switch to an alternative browser if available (Firefox or Chrome). If an alternate browser is not available, avoid adjusting your audio while connected to BigBlueButton.

5.  Use the phone to call into the session (if available).

You’ll find the dial-in numbers in the chat welcome text. Scroll up through the chat window and look for text in color blue.

How do I mute/unmute myself?

The audio controls are at the top of the screen above presentation window.  You can click the mute/unmute button to mute or unmute yourself at any time.Screen Shot 2017-08-15 at 2.22.19 PM.png

You can also click the microphone icon next to your name in the users list under the media column.  

Screen Shot 2017-08-15 at 2.22.30 PM.png

Hint: If you are dialing into the conference via the phone, you can mute/unmute yourself by pressing the ‘0’ key on your phone’s dialpad.

I got disconnected, how do I rejoin?

If you are on a wireless network connection, you may get momentarily disconnected -- BigBlueButton will attempt to auto-reconnect.

If you continue to get reconnected, try connecting via a wired ethernet cable directly to the network (a wired connection is more stable than wireless).  If a wired connection isn’t an option, try switching to a different wireless connection.  

If you see the words ‘[ Tunneling ]’ in the lower right-hand corner, it means that you are behind a firewall that is preventing a direct connection to the server.  Try connecting from a different network.

How do I share my desktop (presenter)?

You need to have Java installed to run the desktop sharing.

A presenter can share their desktop by pressing the desktop share icon in the upper left-hand corner.  Pressing the icon downloads screenshare.jnlp which, when opened, will launch an external Java applet that will share the desktop.

Watch the following tutorial video to learn how to launch desktop sharing:

Can I Join Multiple BigBlueButton Meetings?

You can join multiple meetings; however, be sure you are entering the secondary meeting in a separate browser than that of the original meeting - this will ensure your browser permissions are not overridden by the original meeting.

Why am I receiving a “Cannot Connect to WebRTC” message?

If you are receiving this message, you can refresh your browser (F5 on PC’s and Command+R on most Mac’s) being sure to reconnect your audio/mic.

If you continue to receive this message, you can choose to join audio using Flash.

If neither connecting directly through WebRTC nor through Flash is working, you may be connected through a secure network that is restricting the WebRTC audio connection. In this case, it is best you join “Listen only”.

In some meetings, you’ll find the dial-in numbers in the chat welcome text. Scroll up through the chat window and look for text in color blue.

Why can’t I save screenshare.jnlp in Chrome 65?

Note: The latest version of Chrome is now Chrome 66.  We’ll leave this section in for one more update to Chrome before deleting it.

65 for Mac OS X (released 2018-03-18) is not showing the default “Keep” option for saving downloaded files -- they are only showing “Discard” button.

To show the Keep option, first click Show All button on the right of the download bar ...  

And in the Downloads screen click Keep.

From there you can choose Show in Finder

And then right-click and open the downloaded screenshare.jnlp file.  (When you right-click to open, Mac OS X will let you open the downloaded file).

We put together a quick YouTube Video on how to do this: 

Content in this document is licensed under a Creative Commons Attribution 4.0 International license.