High-dynamic-range television (HDR-TV) is a technology that uses high dynamic range (HDR) to improve the quality of display signals. It is contrasted with the retroactively-named standard dynamic range (SDR). HDR changes the way the luminance and colors of videos and images are represented in the signal and allows brighter and more detailed highlight representation, darker and more detailed shadows, and more intense colors.

HDR allows compatible displays to receive a higher-quality image source. It does not improve a display's intrinsic properties (brightness, contrast, and color capabilities). Not all HDR displays have the same capabilities, and HDR content will look different depending on the display used, and the standards specify the required conversion depending on display capabilities.

HDR-TV is a part of HDR imaging, an end-to-end process of increasing the dynamic range of images and videos from their capture and creation to their storage, distribution and display. Often, HDR is used with wide color gamut (WCG) technology. WCG increases the gamut and number of distinct colors available. HDR increases the range of luminance available for each color. HDR and WCG are separable but complementary technologies. Standards-compliant HDR display also has WCG capabilities, as mandated by Rec. 2100 and other common HDR specifications.

The use of HDR in television sets began in the late 2010s. By 2020, most high-end and mid-range TVs supported HDR, and some budget models did as well. HDR-TVs are now the standard for most new televisions.

There are a number of different HDR formats, including HDR10, HDR10+, Dolby Vision, and HLG. HDR10 is the most common format and is supported by all HDR TVs. Dolby Vision is a more advanced format that offers some additional features, such as scene-by-scene mastering. HDR10+ is a newer format that is similar to Dolby Vision but is royalty-free. HLG is a broadcast HDR format that is used by some TV broadcasters.

Before HDR, improvements in display fidelity were typically achieved by increasing the pixel quantity, density (resolution) and the display's frame rate. By contrast, HDR improves the perceived fidelity of the existing individual pixels. Standard dynamic range (SDR) is still based on and limited by the characteristics of older cathode-ray tubes (CRTs), despite the huge advances in screen and display technologies since CRT's obsolescence.

SDR formats are able to represent a maximum luminance level of around 100 nits. For HDR, this number increases to around 1,000–10,000 nits. HDR can represent darker black levels and more saturated colors. The most common SDR formats are limited to the Rec. 709/sRGB gamut, while common HDR formats use Rec. 2100, which is a wide color gamut (WCG).

In practice, HDR is not always used at its limits. HDR contents are often limited to a peak brightness of 1,000 or 4,000 nits and P3-D65 colors, even if they are stored in formats capable of more. Content creators can choose to what extent they make use of HDR capabilities. They can constrain themselves to the limits of SDR even if the content is delivered in an HDR format.