# Ultra HD Blu-ray
**Ultra HD Blu-ray** is an optical disc format defined by the Blu-ray Disc Association (BDA) that stores 4K Ultra HD video at up to 3840 x 2160 pixels with high dynamic range (HDR), wide color gamut, and immersive audio on high-capacity discs. It is a higher-capacity, higher-bitrate extension of the existing Blu-ray Disc format rather than a new container, and it is commonly marketed as 4K UHD.[1](https://us.blu-raydisc.com/ultrahd-benefits/) • [2](https://freemkv.org/docs/uhd/)
| Key fact | Detail |
|---|---|
| Resolution and frame rate | Up to 3840 x 2160 progressive, at 24, 25, 50, or 60 frames per second[1](https://us.blu-raydisc.com/ultrahd-benefits/) |
| Video codec | HEVC (H.265), Main 10 profile[2](https://freemkv.org/docs/uhd/) |
| Disc capacities | Dual layer 66 GB and triple layer 100 GB (standard Blu-ray holds 25/50 GB)[1](https://us.blu-raydisc.com/ultrahd-benefits/) • [3](https://us.blu-raydisc.com/wp-content/uploads/sites/2/2019/09/20150513-BDA-Completes-UHD-BD-Spec1.pdf) |
| HDR support | HDR10 baseline; Dolby Vision via profile 7 dual-layer encoding[4](https://professional.dolby.com/siteassets/pdfs/dolby_vision_uhd_bluray_authoring_workflow.pdf) |
| Color | Wide Color Spectrum covering over 75% of the visible color spectrum, more than twice the range of the digital TVs current when the format launched[5](https://us.blu-raydisc.com/faqs/) |
| Audio | Up to 7.1 channels of uncompressed surround sound, plus object-based formats Dolby Atmos and DTS:X[5](https://us.blu-raydisc.com/faqs/) |
| Region coding | None; Ultra HD Blu-ray Discs are region-free and play on any compatible player[6](https://www.sony.it/electronics/support/articles/00029369) |
| Specification completed | May 12, 2015, with the official logo released the same day[3](https://us.blu-raydisc.com/wp-content/uploads/sites/2/2019/09/20150513-BDA-Completes-UHD-BD-Spec1.pdf) |
## Specification and capacities
The BDA announced completion of the Ultra HD Blu-ray specification on May 12, 2015, describing it as the work of companies from the consumer electronics, IT, and content creation industries and scheduling format licensing for summer 2015.[3](https://us.blu-raydisc.com/wp-content/uploads/sites/2/2019/09/20150513-BDA-Completes-UHD-BD-Spec1.pdf) The format uses the same blue-violet laser reading technology as Blu-ray Disc, with improved lens specifications allowing a smaller focus spot and higher-density pits, which is what raises capacity five to twenty times above DVD's 4.7 GB.[5](https://us.blu-raydisc.com/faqs/)
**Capacity and data rate.** Ultra HD Blu-ray Discs come in dual layer 66 GB and triple layer 100 GB versions, against 25 GB and 50 GB for standard single- and dual-layer Blu-ray.[1](https://us.blu-raydisc.com/ultrahd-benefits/) • [3](https://us.blu-raydisc.com/wp-content/uploads/sites/2/2019/09/20150513-BDA-Completes-UHD-BD-Spec1.pdf) The BDA states the format can stream video at up to 108/128 Mbps for 66 GB and 100 GB discs respectively.[1](https://us.blu-raydisc.com/ultrahd-benefits/) Sony's own player documentation gives the comparison differently, citing a maximum of about 54 Mbps on standard Blu-ray versus about 100 Mbps on Ultra HD Blu-ray.[7](https://www.sony.jp/CorporateCruise/Press/201705/17-0508B/?cpint=bd-player_sony_news-whatsnew-ja_JP-responsivegrid_initial_middle_sonynews_1167253128_4)
## Video: resolution, HDR, and color
The format's video payload is HEVC (H.265) Main 10, a 10-bit codec chosen for roughly double the compression efficiency of the H.264/AVC used on standard Blu-ray.[2](https://freemkv.org/docs/uhd/) • [7](https://www.sony.jp/CorporateCruise/Press/201705/17-0508B/?cpint=bd-player_sony_news-whatsnew-ja_JP-responsivegrid_initial_middle_sonynews_1167253128_4) [Resolution](https://www.edgepedia.org/resolution) reaches 3840 x 2160, four times the pixel count of Full HD and 27 times that of standard definition, at progressive frame rates of 24, 25, 50, and 60 fps.[1](https://us.blu-raydisc.com/ultrahd-benefits/)
**HDR.** High Dynamic Range widens the difference between the brightest whites and darkest blacks a scene can show, so high-contrast scenes retain detail in highlights and shadows.[5](https://us.blu-raydisc.com/faqs/) [HDR10](https://www.edgepedia.org/hdr10) is the baseline HDR system on Ultra HD Blu-ray, and the format also carries the BT.2020 wide color gamut, which Sony credits with enabling color reproduction not possible on earlier Blu-ray Discs or television broadcasts.[7](https://www.sony.jp/CorporateCruise/Press/201705/17-0508B/?cpint=bd-player_sony_news-whatsnew-ja_JP-responsivegrid_initial_middle_sonynews_1167253128_4) The BDA's Wide Color Spectrum figure is over 75% of the visible color spectrum, more than twice the range of the digital TVs current when the format launched.[5](https://us.blu-raydisc.com/faqs/)
**Playback chain requirements.** To output 4K HDR, a player must be connected to a 4K/60p/4:4:4 and Ultra HD Blu-ray HDR compliant display using an 18 Gbps high-speed HDMI cable, and TVs supporting 4K60p are compatible with HDCP 2.2 copy protection.[8](https://www.documents.philips.com/assets/20230823/7d429874bbf94eea9d3db0670056df52.pdf) Players also provide downconversion and HDR-to-SDR conversion so that Ultra HD discs can be watched on ordinary HDTVs, outputting a standard HD signal when so connected.[1](https://us.blu-raydisc.com/ultrahd-benefits/)
## Dolby Vision on disc
[Dolby Vision](https://www.edgepedia.org/dolby-vision) content on Ultra HD Blu-ray uses the Dolby Vision profile 7 dual-layer encoding approach, which complies with the UHD Blu-ray Disc HDR specifications and serves both HDR10 and Dolby Vision compatible devices.[4](https://professional.dolby.com/siteassets/pdfs/dolby_vision_uhd_bluray_authoring_workflow.pdf) The structure has two layers:
- The **base layer** is a 10-bit video bitstream of the full picture built to HDR10 standards, so non-Dolby Vision HDR10 decoders can decode and play the signal in HDR10.[4](https://professional.dolby.com/siteassets/pdfs/dolby_vision_uhd_bluray_authoring_workflow.pdf)
- The **enhancement layer** is a 10-bit bitstream carrying the residual between the mezzanine source and the base layer, plus the dynamic metadata for Dolby Vision. When the residual is zero the layer is called a minimum enhancement layer (MEL), which minimizes processing requirements on Ultra HD Blu-ray system-on-chips; a nonzero residual makes it a full enhancement layer (FEL).[4](https://professional.dolby.com/siteassets/pdfs/dolby_vision_uhd_bluray_authoring_workflow.pdf) • [9](https://ott.dolby.com/OnDelKits/Dolby_Vision_Online_Delivery_Kit/v1/Documentation/Specs/Visio_Profiles/help_files/topics/c_notes_profile_public.html)
Dolby recommends authoring such discs with a dual playlist, one for Dolby Vision players and one for non-Dolby Vision HDR10 players, to maximize backward compatibility across player firmware versions.[4](https://professional.dolby.com/siteassets/pdfs/dolby_vision_uhd_bluray_authoring_workflow.pdf) 4K Blu-rays use profile 7 specifically, while profile 5 is the single-layer variant used by streaming services.[10](https://www.rtings.com/tv/learn/hdr10-vs-dolby-vision)
## Audio
Ultra HD Blu-ray supports up to 7.1 channels of uncompressed surround sound and object-based immersive formats such as [Dolby Atmos](https://www.edgepedia.org/dolby-atmos) and DTS:X, which add height channels, for example speakers in the ceiling, to the surround field.[5](https://us.blu-raydisc.com/faqs/) Player output over HDMI covers LPCM up to 7.1 channels, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, and DTS:X at 7.1 channels, among other formats.[11](https://www.sony.com/electronics/support/articles/00170959)
## Region coding
Standard Blu-ray Discs carry letter-based region codes (Zone A: the Americas, [Japan](https://www.edgepedia.org/japan-epzdpsev89), Korea, Taiwan, and parts of Southeast Asia; Zone B: Europe, Africa, the Middle East, Australia, and New Zealand; Zone C: the rest of Asia), and a player's region setting cannot be changed.[6](https://www.sony.it/electronics/support/articles/00029369) Ultra HD Blu-ray Discs have no region codes: they play on any player that supports the format regardless of where the disc was purchased.[6](https://www.sony.it/electronics/support/articles/00029369)
## Adoption and later developments
Sony Pictures Home Entertainment announced its first 4K Ultra HD releases on November 10, 2015, naming [The Amazing Spider-Man 2](https://www.edgepedia.org/the-amazing-spider-man-2), Salt, Hancock, Chappie, Pineapple Express, and [The Smurfs 2](https://www.edgepedia.org/the-smurfs-2) for arrival in early 2016, with HDR and, on many titles, next-generation immersive audio.[12](https://www.sonypictures.com/corp/press_releases/2015/11_15/111015_4kultrahddiscs.html) The first 4K Blu-ray discs reached the market in 2016.[13](https://www.whathifi.com/tv-home-cinema/televisions/the-defining-tv-formats-of-the-21st-century-1080p-oled-3d-4k-8k-and-beyond-and-the-first-time-what-hi-fi-reviewed-them) Sony's first Ultra HD Blu-ray player, the UBP-X800, launched in Japan on June 24, 2017.[7](https://www.sony.jp/CorporateCruise/Press/201705/17-0508B/?cpint=bd-player_sony_news-whatsnew-ja_JP-responsivegrid_initial_middle_sonynews_1167253128_4)
**Dolby Vision 2.** Dolby has confirmed that its next-generation HDR format, Dolby Vision 2, can work on existing 4K Blu-ray discs and players, but enabling it requires a firmware update that each manufacturer must decide to provide. When asked, Sony stated it does not plan to provide a software or firmware update to support Dolby Vision 2 on its current Blu-ray player lineup.[14](https://www.techradar.com/televisions/blu-ray/good-news-4k-blu-ray-fans-dolby-confirms-that-dolby-vision-2-hdr-can-work-on-existing-players-and-disc-tech-bad-news-its-up-to-the-manufacturers-and-sony-already-said-we-do-not-plan-to-provide-an-update) • [15](https://www.whathifi.com/tv-home-cinema/blu-ray-players/dolby-vision-2-hdr-can-work-on-existing-4k-blu-ray-players-but-theres-a-catch)
## References
1. [Ultra HD Benefits, Blu-ray Disc Association](https://us.blu-raydisc.com/ultrahd-benefits/)
2. [Ultra HD Blu-ray (4K UHD), freemkv documentation](https://freemkv.org/docs/uhd/)
3. [Blu-ray Disc Association Completes Ultra HD Blu-ray Specification and Releases New Logo (May 12, 2015)](https://us.blu-raydisc.com/wp-content/uploads/sites/2/2019/09/20150513-BDA-Completes-UHD-BD-Spec1.pdf)
4. [Dolby Vision UHD Blu-ray Authoring Workflow Guide, Dolby Laboratories](https://professional.dolby.com/siteassets/pdfs/dolby_vision_uhd_bluray_authoring_workflow.pdf)
5. [FAQs, Blu-ray Disc Association](https://us.blu-raydisc.com/faqs/)
6. [Do Blu-ray Discs have a region code?, Sony support](https://www.sony.it/electronics/support/articles/00029369)
7. [Sony's first Ultra HD Blu-ray player (UBP-X800) press release, Sony (May 8, 2017, Japanese)](https://www.sony.jp/CorporateCruise/Press/201705/17-0508B/?cpint=bd-player_sony_news-whatsnew-ja_JP-responsivegrid_initial_middle_sonynews_1167253128_4)
8. [Player operating manual, Philips (4K/HDR connection requirements)](https://www.documents.philips.com/assets/20230823/7d429874bbf94eea9d3db0670056df52.pdf)
9. [Notes to profiles, Dolby Vision bitstream profiles documentation](https://ott.dolby.com/OnDelKits/Dolby_Vision_Online_Delivery_Kit/v1/Documentation/Specs/Visio_Profiles/help_files/topics/c_notes_profile_public.html)
10. [HDR10 vs HDR10+ vs Dolby Vision: What's The Difference?, RTINGS.com](https://www.rtings.com/tv/learn/hdr10-vs-dolby-vision)
11. [Supported sound characteristics and audio formats of the 4K UHD Blu-ray Disc Player, Sony](https://www.sony.com/electronics/support/articles/00170959)
12. [Sony Pictures Home Entertainment Unveils First 4K Ultra HD Discs, Sony Pictures Entertainment (November 10, 2015)](https://www.sonypictures.com/corp/press_releases/2015/11_15/111015_4kultrahddiscs.html)
13. [The defining TV formats of the 21st century, What Hi-Fi?](https://www.whathifi.com/tv-home-cinema/televisions/the-defining-tv-formats-of-the-21st-century-1080p-oled-3d-4k-8k-and-beyond-and-the-first-time-what-hi-fi-reviewed-them)
14. [Dolby confirms Dolby Vision 2 HDR can work on existing players and disc tech, TechRadar](https://www.techradar.com/televisions/blu-ray/good-news-4k-blu-ray-fans-dolby-confirms-that-dolby-vision-2-hdr-can-work-on-existing-players-and-disc-tech-bad-news-its-up-to-the-manufacturers-and-sony-already-said-we-do-not-plan-to-provide-an-update)
15. [Dolby Vision 2 HDR can work on existing 4K Blu-ray players, but there's a catch, What Hi-Fi?](https://www.whathifi.com/tv-home-cinema/blu-ray-players/dolby-vision-2-hdr-can-work-on-existing-4k-blu-ray-players-but-theres-a-catch)
---
*Topic: Encyclopedia › Technology and the built world › Computing and digital systems › Computer hardware › Storage devices & memory › Optical storage*
*Initially written Sep 17, 2026 · Reviewed: Sep 17, 2026; Sep 30, 2026; Oct 15, 2026 · Edited: Sep 30, 2026; Oct 15, 2026; Oct 25, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license