It’s Not HDR10+’s Bit Depth Holding Back Your Picture — It’s the Codec
“HDR10+ is capped at 10-bit color” is one of the most repeated claims about the format online — and it’s wrong. The HDR10+ specification has supported quantization up to 16 bits since it was first introduced in 2017, with no change to that ceiling in HDR10+ ADVANCED. What’s actually limiting today’s streaming HDR to 10-bit delivery isn’t the format. It’s the codec.
What bit depth controls
Bit depth sets how many distinct brightness and color steps a format can use to describe the transition from one value to the next. Every additional bit quadruples that precision: 8-bit gives 256 levels per color channel, 10-bit gives 1,024, and so on. More steps means smoother gradients and finer color transitions, with less risk of visible banding in skies, shadows, and other gradual tones.
The specification vs. what gets delivered today
Here’s the distinction that gets lost in most coverage: HDR10+ the specification supports quantization up to 16 bits. What streaming services actually deliver today is 10-bit, because that’s the current ceiling of practical streaming video codecs — a constraint on the delivery pipeline, not on HDR10+ itself. Every major HDR format runs into the same codec ceiling. The standard isn’t the limit; the codec is.
The “12-bit” marketing claim doesn’t hold up either
Some competing HDR formats are marketed around 12-bit support. In actual streaming delivery, those formats are also capped at 10-bit, identical to HDR10+ — the 12-bit capability refers to a specific disc format with very limited real-world studio adoption, not to what reaches most viewers. A separate claim holds that a particular color-encoding method (ICtCp, in place of standard Y’CbCr) makes 10-bit “equivalent to 12-bit.” The peer-reviewed study behind that claim puts the actual coding-efficiency gain at roughly 10% for HDR/WCG content — real, but a modest advantage, and far short of the four-fold precision difference that separates 10-bit from 12-bit outright.
Bit depth and brightness are separate specs
It’s also worth untangling bit depth from peak brightness, since the two get conflated constantly. HDR10+ uses the PQ (Perceptual Quantizer) transfer function defined in SMPTE ST 2084, which covers content from 0 to 10,000 nits regardless of bit depth. Claims that a 10-bit signal caps HDR10+’s brightness at some lower ceiling are technically incorrect — the two specs are independent of each other.
Independent confirmation
Tom’s Hardware’s breakdown of color depth standards confirms the underlying math on precision — an 8-bit panel is limited to 256 shades per channel, while 10-bit “quadruples” that to roughly 1.07 billion total colors — and notes that with today’s panel brightness and color-range limitations, very few viewers can actually distinguish a well-implemented 10-bit signal from a 12-bit one in practice.
Read Tom’s Hardware’s full explainer on 10-bit and 12-bit color for more detail.
The ~10% figure on ICtCp coding efficiency comes from a peer-reviewed comparison study: Perrin, Rerábek, Husak, and Ebrahimi, “ICtCp Versus Y’CbCr: Evaluation of ICtCp Color Space and an Adaptive Reshaper for HDR and WCG,” IEEE Consumer Electronics Magazine, Vol. 7, No. 3 (2018), pp. 38–47. Read the paper on IEEE Xplore.