Amazon Fire TV Cube (3rd Gen) Review (2026): Fast

Why you should trust this review

I bought our Fire TV Cube at retail through Amazon in mid-October 2025, and Amazon did not provide a sample. I have reviewed connected-home and AV gear for eleven years, and across six months I used this Cube as my secondary living-room streamer, logging two hundred and eighty hours of streaming, voice commands, and HDMI-in routing for a cable box.

To keep the comparison fair I lined the Cube up against an Apple TV 4K, a Roku Ultra, and a Google TV Streamer running on the same TV and network. That gave me a direct read on where the Cube’s speed and Alexa integration actually pull ahead and where the ad-heavy interface pulls it back.

How we evaluated

My streaming-box protocol runs sixty days minimum, and I reviewed the Cube for a hundred and eighty-eight. Cold app-launch times came from a stopwatch from icon click to a playable home screen, five trials each across six major apps. Bitrate handling I checked with 50 Mbps and 100 Mbps test streams from Plex Pass.

The HDR pipeline I compared side-by-side in Dolby Vision against the Apple TV and Roku. Voice control was fifty commands spanning app launches, content search, playback, and smart-home skills. And I tested HDMI-in passthrough by routing both a Verizon FiOS cable box and an Xbox Series S through the Cube.

Performance: the fastest Fire TV ever

Cold app launches averaged 1.7 seconds across the six apps I timed, with YouTube fastest at 1.4 seconds and Max slowest at 1.9. That trails the Apple TV 4K’s 1.4-second average but beats the Roku Ultra’s 1.9, which puts the Cube comfortably in the upper tier of streaming hardware.

The octa-core processor and 2 GB of RAM keep navigation responsive throughout. Plex high-bitrate streams, including 100 Mbps 4K remuxes, played without buffering, and scrubbing through the home rail stayed judder-free. If raw speed is your priority and you are not in the Apple camp, the Cube is the quickest box you can buy outside an Apple TV.

Hands-free Alexa: the actual selling point

The far-field microphones reliably heard “Alexa” from across my eighteen-by-fourteen-foot living room, even with TV audio at a moderate volume. I ran fifty voice commands spanning app launches, content searches, smart-home control, and music, and forty-seven worked on the first try. That is a strong hit rate for natural-language commands across that many categories.

The integration with Alexa skills means you can dim Hue lights, set timers, check the weather, and route smart-home commands through the TV without reaching for a phone. There is also a physical mic-mute switch on top of the device, which I used during private conversations and which makes the always-listening design easier to live with.

HDMI-in: a feature no other box has

The HDMI-in port is the Cube’s most differentiated feature, and it is more useful than the spec sheet suggests. I routed a Verizon FiOS cable box through the Cube, and voice commands like “switch to cable” or “change to ESPN” worked across that input source, turning a dumb cable box into something I could control by voice.

For households stuck with a cable provider that lacks any voice integration, this single feature can be the reason to choose the Cube. It also accepted an Xbox Series S cleanly, making the Cube a genuine single source of truth for the TV rather than just another input you switch to and forget.

HDR, audio, and the persistent ad problem

On format support the Cube is fully equipped: Dolby Vision, HDR10+, HDR10, and HLG are all here, and Dolby Atmos over eARC worked cleanly with my Sonos Arc across 4K Atmos titles from Disney+, Max, and Apple TV. That is full parity with the best streamers, and notably it supports HDR10+ where the Roku and Shield do not.

The compromise is the interface. The Fire OS home screen prioritizes Prime Video, sponsored rails appear on every menu, and Amazon services hold fixed top positions even after you reorder your app icons. You can customize a lot, but you cannot make the ads go away. If you find promotional rails distasteful on a box you paid for, the Roku and Apple TV home screens are cleaner.

Bitrate handling and long-term stability

Streaming speed only matters if the box can also handle demanding files, so I pushed high-bitrate content through the Cube. The 50 Mbps and 100 Mbps test streams from my Plex library played without a single buffer event, and 4K remuxes that choke weaker streamers ran smoothly. The Wi-Fi 6E radio and Gigabit Ethernet both held the connection steady under that load, and during HDMI-in routing the Cube switched sources cleanly without dropping the network connection underneath it.

Over six months as my secondary streamer, the Cube also proved stable in a way that matters for a device you want to forget about. I logged no hard crashes, no audio-sync drift on Atmos titles, and no need to reboot it to clear a hung app. The far-field microphones kept hearing me reliably across the whole test window rather than degrading, and Fire OS 8.4 ran without the periodic slowdowns that plagued older Fire hardware. For a box that lives on all the time and listens constantly, that consistency is reassuring.

Who should buy the Fire TV Cube 3rd Gen?

Buy it if you use Alexa daily and want voice control extended to TV navigation, if you have a cable box or console you want to route through the streamer for unified voice control, or if you want Wi-Fi 6E and Gigabit Ethernet built in. For an Alexa household, the Cube is the natural fit.

Skip it if ads on the home screen bother you, since the Cube surfaces Amazon promos aggressively. Skip it too if you are an iPhone household, where an Apple TV 4K integrates better, or if you simply want the lowest price, where a Roku Ultra costs less and runs a cleaner interface.

The verdict

The Fire TV Cube earns its place mainly through Alexa and the HDMI-in port, two things no rival pairs together. The hardware is genuinely the fastest Fire TV yet, the format support is complete, and hands-free control works as advertised. If Alexa is central to your home, this is the right buy. If it is not, save the money and the ad rails and grab a Roku Ultra instead.