Buffering and Video Resolutions

What is Buffering?
Buffering is when you are streaming a video and the video stops to wait as more of the stream source gets loaded into Kodi. Sometimes, the video will stop and the audio will continue or the video and voice goes out of sink which makes it really difficult to watch.
To properly utilize Kodi, you should know what resolution works best for you. There is no point trying to get sources for 1080p when your internet connection speed is too slow to support that. With Streaming, the better the resolution, the bigger the file source. The bigger the file source, the slower the stream and greater the risk of buffering which will make you want to smash your Kodi device into tiny little pieces. We want to avoid Buffering and the frustration of trying to watch a complete video.
Also keep in mind that resolution isn't the only thing that determines file size. For example a video done with 2 channel sound is much smaller than video done in Dolby 7.1 surround.

Speed Tester

From the System screen of the build you will find a "Speed Tester" listed. Don't rely on what your Internet Provider says it's giving you. There are other factors which can affect your actual connection speed.
The Kodi Speed Tester will measure the speed of your Internet connection received by your Kodi Device. If you use wifi, this could be much less than the speed going to your modem.
The reason why this is important, is it lets you know what kind of streaming quality you can get comfortably. That is to say, if you can stream in SD (Standard Definition - lowest quality), HD 720p, 1080p and 4K.
Of course your video device also determines what video resolution you should aim for.
Depending on your speed test results, here is a chart to show how video resolution relates to speed.

Internet Speed Definition Comments
3 mbps (minimum) Standard (SD) Good but not amazing
5 mbps (minimum) 720p Best for displays 45" or less, still good for larger displays
10 mbps (minimum) 1080p Better for displays larger than 45"
25 mbps (minimum) 4K Best for displays larger than 55"

Keep in mind that these are suggested minimums. If you are paying for a 5 mbps and connect with wifi there is a good chance you won't actually reach that 5 mbps level. There is also a chance that your connection speed will vary depending on how many people are using the same internet provider as you.
You can also lose speed running multiple devices off your internet. Think of the Internet as a water pipe. The more faucets you open, the less water pressure you get. New technology will fix this in the future.
One tip I have, is to use a wifi extender. I have one connected to my Android box and I can get the same speed from my wifi as I get directly from my modem using a direct ethernet cable connection.

Using Advanced Settings

It's also a good idea to use the Advanced Settings feature in Kodi. You can do this using the G-Man Wizard with Kodi. This creates a file Kodi uses to create optimum settings specific to your device.
  • Click on the G-Man Wizard icon at System screen in the main menu.
  • Click on Maintenance, then go down until you see "(G-Man) System Tweaks/Fixes"
  • Click on "Quick Configure AdvancedSettings.xml" the go to the bottom of the pop-up screen and click on "Write File". Now you can exit out of the Wizard.
  • Choosing a Lower Resolution

    I love a good 1080p HD image on my 55" TV, but for watching TV shows, I don't mind dropping down to 720p and I still get a great picture. If worse comes to worse, I can live with SD quality. I know there is a better chance of getting a stable link at a lower resolution. However, for my movies I really don't like anything less than 1080p.
    Using a service like Real Debrid ($3 a month) gives you much more HD links with less chance of buffering.
    If your device only supports 720p, you can still stream a 1080p source, it just won't be displayed in 1080p. This is helpful if you can't find 720p sources but have a few sources available at 1080p. The 4k sources are huge so you may run into buffering problems due to their file size.

    Other Issues

    So, you've done everything I suggest and still getting buffering in some shows. Don't panic, this can happen in the best setups. The Internet is far from perfect.
    Keep in mind that your Internet speed is half the battle. When you click on a source to stream video, your connection speed from your Internet Provide to that server source is affected by;
  • Where their server is located in relation to where you are. If you are pulling a source from another country that affects connection speed.
  • Speed of the server the source resides on. It could be a slow server, or there could be a million people trying to pull a source video off that same server which can really cripple that server.
  • Size of the file you are trying to stream. Yes, size does matter and not all source files are the same size. It's the difference between sucking a pea or a golf ball through a garden hose. If your 1080p link keeps buffering drop down to 720p. If you still have problems try an SD link.
  • Using a VPN can slow you down as well. With a VPN, your connection is going through a third party. You are better off using Real Debrid which acts like a VPN but Real Debrid is also the source provider.

    Kodi Build Manual
    Buffering Issues
    * more to come *