HDMI 2.1
Display Cables · 7 specs
Direct Answer
HDMI 2.1 increases total bandwidth to 48 Gbps via Fixed Rate Link (FRL). It mandates Ultra High Speed HDMI Cable certification and supports Variable Refresh Rate (VRR), Auto Low Latency Mode (ALLM), and eARC.
Source: HDMI 2.1a Specification · Last reviewed Aug 28, 2026
Specs
| Max Resolution @ Refresh Rate | 8K @ 60Hz / 4K @ 120Hz (10K with DSC) |
| Max Bandwidth / Data Rate | 48 Gbps (FRL 4 lanes) |
| Pin Count | 19 Pins (Type A) |
| Display Stream Compression (DSC) | DSC 1.2a Supported |
| Variable Refresh Rate (VRR) | HDMI Forum VRR & Quick Media Switching (QMS) |
| Max Audio Channels | 32 Channels (eARC up to 192kHz / 24-bit uncompressed) |
| Max Recommended Cable Length | 3 Meters (Passive Ultra High Speed) / 100m+ (Active Optical AOC) |
Evolution from HDMI 2.0
HDMI 2.1 was announced by the HDMI Forum in January 2017 and the finalized specification was released that November, more than four years after HDMI 2.0. The Forum has managed the HDMI specification since 2011, taking over from the original group of seven founding companies that created HDMI in 2002.
The jump from HDMI 2.0 to 2.1 nearly tripled maximum bandwidth, from 18 Gbps to 48 Gbps, by introducing a new signaling method called Fixed Rate Link (FRL) in place of the older TMDS (Transition-Minimized Differential Signaling) used since HDMI 1.0. That bandwidth increase is what makes 4K at 120Hz and 8K at 60Hz possible without relying on compression for most content.
New Features Beyond Bandwidth
HDMI 2.1 introduced several gaming- and audio-focused features earlier versions lacked. Variable Refresh Rate (VRR) lets the display's refresh rate match the source's frame rate to reduce stutter and tearing, and Auto Low Latency Mode (ALLM) lets a console or PC automatically switch a TV into its lowest-latency game mode.
On the audio side, enhanced Audio Return Channel (eARC) replaced the original ARC, raising bandwidth enough to carry object-based surround formats like Dolby Atmos and DTS:X in their full, uncompressed form from a TV back to a soundbar or receiver -- something the original ARC's limited bandwidth couldn't support.
Technical Comparisons
Compare all in Display Cables →Related
DisplayPort 2.1
Competing high-bandwidth digital video standard, common on PC monitors and game consoles rather than TVs
DVI
DVI-D shares the same underlying digital video signal -- interoperates via a simple passive adapter, but without audio or guaranteed HDCP support
HDMI 2.0
The previous version, capped at 18 Gbps -- enough for 4K60 but not 4K120 or 8K