What Is an HDMI Cable? HDMI 1.4 vs 2.0 vs 2.1, 4K–8K and Cable Length
HDMI 1.4, 2.0 and 2.1 compared, High Speed, Premium and Ultra High Speed cable classes, ARC and eARC, connector types and passive, active or fibre HDMI by distance.
An HDMI cable carries uncompressed digital video and audio in one lead. More than the version number, the data rate it can carry (Gbps) matters: 4K 60 Hz needs 18 Gbps, 4K 120 Hz and 8K need 48 Gbps. That rate is set by the cable's certification class and its length.
> Related Category: Browse all lengths and classes in HDMI Cables and Video and Audio Cables.
1. HDMI 1.4 vs 2.0 vs 2.1
| Version | Maximum data rate | Maximum video | Key features |
|---|---|---|---|
| HDMI 1.4 | 10.2 Gbps | 4K 30 Hz, 1080p 120 Hz | ARC, Ethernet channel, 3D |
| HDMI 2.0 | 18 Gbps | 4K 60 Hz | HDR, 32 audio channels |
| HDMI 2.1 | 48 Gbps | 4K 120 Hz, 8K 60 Hz | eARC, variable refresh rate (VRR), auto low latency mode (ALLM), dynamic HDR |
The version describes what a device (television, console, graphics card) can do. The chain works at its weakest link: source, cable and display must all support the same level.
2. HDMI cable classes
Cables are sold by certification class, not version number:
| Cable class | Data rate | Supported video |
|---|---|---|
| Standard | ≈ 5 Gbps | 720p, 1080i |
| High Speed | 10.2 Gbps | 1080p, 4K 30 Hz |
| Premium High Speed | 18 Gbps | 4K 60 Hz, HDR |
| Ultra High Speed | 48 Gbps | 4K 120 Hz, 8K 60 Hz, eARC, VRR |
- Premium High Speed is enough for 4K 60 Hz HDR streaming and media players.
- Current consoles and 120 Hz displays need Ultra High Speed; the box carries a certification label.
- A higher class works with older devices; all classes are backward compatible.
- "with Ethernet" means the cable also carries the HDMI Ethernet channel.
3. Connector types
| Type | Name | Use |
|---|---|---|
| Type A | Standard HDMI (19 pins) | Televisions, monitors, consoles, computers |
| Type C | Mini HDMI | Cameras, some tablets |
| Type D | Micro HDMI | Action cameras, small devices |
In tight spaces use a 90° connector or a short flexible adapter; bending the cable sharply at the plug damages screening and cores.
4. ARC and eARC
ARC (audio return channel) sends television sound back to an audio system over the same HDMI cable, so no optical cable is needed. eARC is its high-bandwidth successor and carries uncompressed multichannel and object-based audio.
- Use the HDMI ports marked ARC on both the television and the audio system.
- ARC works on High Speed cable; eARC needs High Speed "with Ethernet" or Ultra High Speed.
- CEC lets one remote switch connected devices on and off together.
5. Choosing cable length
A passive copper cable cannot hold a high data rate over long runs:
| Target video | Passive copper cable | For longer runs |
|---|---|---|
| 1080p | Up to 15 m | Active cable, signal booster |
| 4K 60 Hz (18 Gbps) | Up to 5–7 m | Active HDMI or fibre (AOC) cable |
| 4K 120 Hz / 8K (48 Gbps) | Up to 3 m | Fibre optic (AOC) HDMI cable |
- An active cable contains a signal booster and is directional: the "Source" end goes to the source, "Display" to the screen.
- Fibre optic (AOC) HDMI cables carry 4K and 8K over 10–100 m, are thin and immune to electromagnetic interference; they are directional too.
- Over very long distances video travels through a pair of HDMI extenders on Cat6 cable.
- For projectors and in-wall runs choose small or detachable plug heads and leave at least one spare empty conduit.
- Thicker conductors (lower AWG number) and double screening reduce loss in long cables.
6. Common problems
| Symptom | Likely cause | Remedy |
|---|---|---|
| No picture or intermittent blackouts | Cable too long or too low a class for the data rate | Higher class or shorter cable; test at 30 Hz instead of 60 Hz |
| Sparkles, snow | Marginal signal, loose plug | Reseat the plug, replace the cable |
| 4K 60 Hz or HDR not selectable | Enhanced HDMI mode off on the television input | Enable it for that input in the television settings |
| No ARC sound | Wrong port, CEC off | Use the ARC ports and enable CEC |
Frequently asked questions
What is the difference between HDMI 2.0 and 2.1?
HDMI 2.0 carries up to 18 Gbps for 4K 60 Hz. HDMI 2.1 reaches 48 Gbps and adds 4K 120 Hz, 8K 60 Hz, eARC and variable refresh rate.
Which HDMI cable does a 4K television need?
Premium High Speed (18 Gbps) covers 4K 60 Hz and HDR. Consoles and displays running 4K 120 Hz need Ultra High Speed (48 Gbps).
How long can an HDMI cable be?
Safe limits for passive copper are about 15 m at 1080p, 5–7 m at 4K 60 Hz and 3 m at 8K. Use active or fibre optic HDMI beyond that.
Does a costly HDMI cable improve picture quality?
No. The signal is digital: if the cable carries the required data rate the picture is identical, and if not there are blackouts and sparkles. Certification class and length are what count.
What is the difference between ARC and eARC?
ARC returns compressed audio up to 5.1 channels. eARC carries uncompressed multichannel and object-based audio and arrived with HDMI 2.1.