Variable bit rate vs. constant bit rate

Learn about variable bit rate and how it can help when it comes to exporting your videos.

Bit rate can affect everything from file size to playback ability, which is why it’s important to choose the right one when exporting your videos. Here’s what you need to know about variable bit rate and how it can help your videos export with a smaller file size but maintain higher video quality.

How does bitrate affect video quality?

Bit rate is the number of bits (pieces of information) processed within a certain amount of time. Typically, bit rate is measured in megabits per second, which is one million bits per second.

For example, if a video has a bit rate of 20 megabits per second (20Mbit/s), that means 20,000,000 bits are processed every second to play the video. The higher the bit rate, the better video quality.

CBR vs VBR video quality.

There are two different types of bit rate: variable and constant. Constant bit rate (CBR) maintains a consistent bit rate throughout the entire playback of the video. This makes videos easy to play and quick to load, since everything is constant from start to finish.

Variable bit rate (VBR) uses a dynamic bit rate that changes throughout playback, depending on the level of detail needed. Slow scenes use less bits than fast-moving, action-packed scenes.

While VBR is typically harder for devices to play back — since the bit rate constantly changes — it provides much higher video quality without massive file sizes. It’s best used for videos that will be either progressive downloads (like on YouTube or Vimeo) or direct downloads.

Choose your bit rate before exporting.

Video editors like Adobe Premiere Pro let you choose the bit rate and the type of bit rate before exporting your videos. If you’re creating videos for YouTube or direct downloads, variable bit rate might be for you.

Discover more helpful video tips and tricks, and then explore everything you can do with Premiere Pro to export videos without sacrificing quality or download speed.