Bitrate is the amount of data processed per unit of time in a video stream, typically measured in megabits per second (Mbps) or kilobits per second (kbps). It is one of the most important parameters in video encoding, directly affecting both visual quality and file size. Higher bitrate generally means better quality, but also larger files and higher bandwidth requirements.
Video encoders can operate in different bitrate modes, each offering a different trade-off between file size predictability and visual quality consistency.
| Mode | Full name | Behavior | Best for |
|---|---|---|---|
| CBR | Constant Bitrate | Same bitrate throughout | Live streaming, bandwidth-limited delivery |
| VBR | Variable Bitrate | Bitrate varies with scene complexity | VOD, quality-critical content |
| CRF | Constant Rate Factor | Targets consistent visual quality | Archival, per-title encoding |
The optimal bitrate depends on the resolution, codec, and content complexity. High-motion content (sports, action) requires higher bitrates than low-motion content (presentations, interviews) at the same resolution.
| Resolution | H.264 bitrate | H.265/VP9 bitrate | Typical use |
|---|---|---|---|
| 360p | 0.6-1 Mbps | 0.4-0.7 Mbps | Mobile on slow networks |
| 480p | 1-2.5 Mbps | 0.7-1.5 Mbps | Standard definition |
| 720p | 2.5-5 Mbps | 1.5-3 Mbps | HD quality |
| 1080p | 5-10 Mbps | 3-6 Mbps | Full HD |
| 1440p | 10-16 Mbps | 6-10 Mbps | 2K |
| 2160p (4K) | 16-30 Mbps | 10-18 Mbps | Ultra HD |
Bitrate directly impacts three factors: visual quality, file size, and required bandwidth. The goal of modern video delivery is to find the optimal bitrate for each content — high enough for sharp, artifact-free images, but low enough for efficient delivery.
Videas encodes at constant quality with a bitrate ceiling per level: the encoder spends more data on complex scenes and less on static shots, without ever exceeding the ceiling for that level. The target ladder is 2.5 Mbps at 1080p, 1.2 Mbps at 720p, 600 kbps at 480p and 300 kbps at 360p, with 50% of headroom above for busy scenes. Combined with adaptive bitrate streaming, this gives every viewer the best quality their connection can carry, with no encoding settings on your side.
For 1080p video, 5-8 Mbps with H.264 or 3-5 Mbps with H.265/VP9 delivers good quality. The optimal bitrate depends on content type, codec and viewer bandwidth. Videas handles this automatically with adaptive bitrate streaming.
Only up to a point. Every resolution has a quality ceiling beyond which extra bitrate brings no visible improvement. A 1080p video at 20 Mbps looks practically identical to the same video at 8 Mbps. Efficient encoding targets the sweet spot.
CBR (Constant Bitrate) keeps the same data rate throughout the video, which is predictable but wastes bandwidth on simple scenes. VBR (Variable Bitrate) allocates more data to complex scenes and less to simple ones, giving better overall quality at the same average file size.
2.5 Mbps at 1080p, 1.2 Mbps at 720p, 600 kbps at 480p and 300 kbps at 360p, with a ceiling set at one and a half times the target to absorb complex scenes. The same targets serve both codecs; VP9, being more efficient, rarely gets close.
Resolution counts pixels, bitrate counts data per second. A 1080p at 500 kbps will look worse than a 720p at 1.5 Mbps: quality comes from the pair, never from resolution alone.
No. The interface exposes no encoding settings — no bitrate, no codec, no resolution. The viewer, on the other hand, can lock a resolution or turn on eco mode, which caps playback at 720p.
Indirectly. Delivery is billed at EUR 0.02 per gigabyte actually watched, with the first terabyte free each month: a viewer served the 1080p level consumes more than a viewer at 360p. Storage, by contrast, is counted per hour of video, whatever the bitrate.
Because your master is encoded for editing or archiving, not for delivery. A streaming 1080p targets 2-3 Mbps where a master spends 8-12. The difference shows on a freeze frame, almost never during playback.
The ceiling the encoder allows itself on a complex scene, above the target bitrate. On Videas it is one and a half times the target: 3.75 Mbps for a 1080p targeting 2.5. That ceiling stops a busy shot from stalling a viewer on a marginal connection.
You set it yourself, in OBS, vMix or whichever encoder you use: Videas receives the feed as you send it, then transcodes it into several qualities and adapts it to each viewer.