When setting up your stream in OBS, you'll need to decide a video bitrate. Below is a basic guide for creative streaming rates.
First: Run an internet speed test on Speedtest.net to find out what your upload speed is. Speedtest by default measures in mbps, but your OBS bitrate is in kbps. 1000kbps = 1mbps. The following conditions are a basic rule of thumb, and you should test your stream and adjust your bitrate to make sure everything runs smoothly for your particular set up.
If you have an upload speed of less than 500kbps / 0.5mbps:
I’m afraid it’s going to be hard to stream much of anything. While it’s possible to stream on a bitrate this low, you would need a higher upload speed for extra cushioning to ensure your stream runs smoothly. I don’t recommend you try to stream, unless you’ve tested everything and can guarantee a smooth connection.
If your upload speed is around 1000kbps / 1mbps:
Use anywhere between 400-700 for your bitrate, and you should be able to stream comfortably in 720p. Your stream may lag if there's any fast or intensive movements on screen, such as a moving camera, facecam, or video/gifs playing.
If your upload speed is 2000-3000kbps / 2-3mbps:
Try 1500 bitrate if you want to stream in 720p. You can try using 2000-2500 for a 1080p stream, but you may want to test and make sure this works fine with your computer and connection.
If your upload speed is over 4000kbps / 4mbps:
You can stream comfortably in 1080p with a bitrate anywhere between 2000-3500. Using a higher bitrate will be harder on your CPU, and often isn't necessary.
Audio Bitrate: It’s widely recommended you use 112 or 128 for your audio bitrate, no matter what you’re streaming. Your audio and video bitrate will combine into one number, and that is the total bitrate used by your stream.
No matter which category you fall into, be sure to test your stream, watch the quality, and adjust if you find you’re dropping any frames.
Testing your stream: In Settings > Stream, check the box to enable Bandwidth Test Mode. Enabling this will stop your stream from appearing live on Twitch, but will still upload data to allow you to monitor your frames and stability in OBS.
When you're live, OBS will display some basic information for you at the bottom of the window. These show how many frames you're dropping, how long you've been live for, how long you've been recording for, how much of your CPU is being dedicated to the stream, and your current bitrate.
This is a great looking status bar. The total video and audio bitrate for this stream is 1624, so everything is running smoothly as expected. As long as that connection box is green, you're good to go.
Here's what you can expect to see if you have a slow internet connection or bad weather etc. Dropping frames here and there is a normal occurrence, no matter how good your internet is. But when you're at an 80% drop, your stream will be unviewable.
For more information about your stream, you can also open the Stats window (View > Stats). This window gives you all the information you need about your computer usage, frame drops, recording drops, and even your internet usage.