Smart Plug Energy Monitor
Best for: Best for genuinely accurate per-appliance energy monitoring and home automation at a low price — expect some WiFi/outlet-position trial and error, and check current firmware if you need local scripting access.
Check price on Amazon →How we pick: we feature gadgets we’ve actually used or tested, score them honestly, and only recommend the ones that earn it. We may earn from qualifying Amazon purchases.
TidyHacks verdict
Video coming soon
We're filming the TidyHacks Short for this product. Subscribe on YouTube to catch it first.
Our review
A genuine energy-monitoring smart plug for $15.99 is hard to beat, and the Kasa KP115 backs that up with real precision — one detailed reviewer who compared it to a dedicated Kill-A-Watt meter found the Kasa's voltage, current and power readings were actually more precise. At 4.5 stars from nearly 18,000 ratings, it has built a strong reputation with home automation enthusiasts specifically, not just casual smart-home buyers.
The compact "mini" design is a genuine selling point: it does not block the second socket on a duplex outlet, the bi-stable mechanical switch holds its on/off state through a power cut without needing to reboot, and the energy-usage total survives a power loss too, rather than resetting to zero. Reviewers use it for genuinely practical automation: cutting power to a dehumidifier before a freeze, automating an irrigation valve a rain sensor cannot always catch, and monitoring how much a small solar setup produces from 60 feet away. It also supports local network control over TP-Link's own protocol, appealing to privacy-conscious users who would rather it not depend on the cloud.
Two real niggles are worth flagging. First, performance is noticeably sensitive to WiFi signal and even which specific outlet you use — one reviewer found a unit that seemed faulty worked perfectly once moved to a different socket, and ended up buying a second router for reliable coverage to a garden shed. Second, a more recent firmware update removed the local API access some users previously relied on for custom scripting, confirmed directly with TP-Link support by one reviewer — check current firmware behaviour first if script-level local control matters to you. Resetting the cumulative energy total also is not built into the main Kasa app; a few reviewers use a separate third-party app for that.
For straightforward voice control, scheduling, and genuinely accurate energy monitoring at this price, it remains a clear favourite — just be aware of the WiFi sensitivity and the local-API change if those matter to you.
More photos & videos
👍 Pros
- Energy readings reported as more precise than a dedicated Kill-A-Watt meter by one detailed reviewer
- Compact mini design does not block the second socket on a duplex outlet
- Bi-stable switch holds its on/off state through a power cut; energy totals survive power loss too
- Supports local network control via TP-Link's own protocol, not just cloud-dependent
- Used for genuinely practical automation — dehumidifiers, irrigation valves, solar monitoring from 60ft away
👎 Cons
- Performance is noticeably sensitive to WiFi signal and even which specific outlet you use
- A recent firmware update removed local API access some users relied on for custom scripting
- Resetting the cumulative energy total is not built into the main Kasa app — needs a separate third-party app
- Local/third-party integrations (e.g. Home Assistant) still require creating a Kasa account first
Specifications
| Brand | Kasa Smart (TP-Link), model KP115 |
|---|---|
| Rating | 15A, 120V |
| Material | Metal, fireproof shell, sliding child-safety cover |
| Connectivity | 2.4GHz WiFi only, no hub required |
| Control | Kasa app, Alexa, Google Home, local network protocol |
| Monitoring | Real-time + historical energy usage, survives power loss |
| Price | $15.99 |
FAQ
Is the energy monitoring accurate?
Reviewers report it as genuinely precise, with one detailed comparison finding it more accurate than a dedicated Kill-A-Watt meter.
Will it work without internet access?
Mostly yes for on/off control via TP-Link's local protocol, though scheduling needs an internet connection to set the device's clock initially.
Can I control it with my own scripts?
A recent firmware update removed local API access some users relied on for this — check current firmware behaviour before depending on it.
Why does it work in one outlet but not another?
WiFi signal strength varies a lot by outlet location — several reviewers found moving the plug or adding a router fixed connectivity issues.
More Tech & Smart Home reviews
Get the best Amazon finds each week
One short email. New reviews, viral finds and the odd deal. No spam.