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In this guide
Color-changing bulbs live or die on two questions that have nothing to do with color: how they are controlled, and what happens to the wall switch. The KL125 answers the first with a phone app and three voice assistants, and the second with a datasheet line saying it is not compatible with regular light switches and should not be used with standard dimmers. Read those before the 16 million colors.
What the bulb offers in return is a full A19 replacement: 800 lumens, a 9 W draw, white from warm 2500 K to cool 6500 K, and a two-year US warranty that is unusual at ten dollars a bulb. It joins the same Kasa app as the KP125M plug we covered, but unlike that plug it carries no Matter logo, and the difference decides who should buy it.
Our verdict
A reasonable color bulb for lamps and fixtures you control from a phone or a voice assistant, priced at ten dollars a bulb in the 2-pack and less in the 4-pack. Every dimming and color function runs through the Kasa app and cloud, the wall switch must stay on, and neither the page nor the datasheet mentions Matter.
- A good fit for
- A household already using Alexa, Google Assistant or SmartThings that wants tunable white and color in a few table lamps or open fixtures and is fine keeping a TP-Link account for as long as the bulbs are in service.
- We would skip it if
- You want a bulb that joins Apple Home or a local Matter hub, you plan to put it in an enclosed or recessed fixture, or you expect the wall switch or an existing dimmer to keep working as before.
Reasons to consider it
- 800 lumens at 9 W with a stated CRI of 90 or higher, tunable from 2500 K to 6500 K, and dimming down to 1 percent
- Two years of warranty coverage for US buyers, stated on Kasa's own page
- No hub: the bulb joins a 2.4 GHz network directly, with pack prices as low as $6.39 per bulb at the retailer Kasa links to
The compromises
- Dimming, tuning and color changing are listed as available via app and cloud only, so a wall dimmer or a plain switch cannot do the job
- Matter appears nowhere on the page or in the datasheet, which means no direct Apple Home path and continued dependence on TP-Link's cloud
- The datasheet bars use in totally enclosed or recessed luminaires and with standard dimmers, photosensors, motion sensors or timers
What we have not verified: We have not installed this bulb, measured its light output or color accuracy, or checked how it behaves when the Kasa cloud is unreachable. The 25,000-hour figure is our arithmetic from the datasheet's 22.8 years at three hours a day, not a number Kasa prints. The page and the datasheet disagree on wattage, weight, height and which safety mark applies, and we could not resolve which is current. Prices are from Amazon listings reached through Kasa's buy buttons, not from Kasa itself.
The things in this guide
A closer look at the products, who they may suit, and what to check before buying.
Smart Wi-Fi Light Bulb, Multicolor · KL125
At $25.57 for four on the Amazon listing Kasa links to, the per-bulb cost drops to $6.39, and the app, schedules and voice control are the same whether you own one bulb or twenty.
Before you buy: Each bulb needs a fixture that stays powered and is neither enclosed nor recessed, and every color and dimming function stops at the Kasa cloud, so a home that needs local or Apple Home control is better served by a Matter bulb.
Price checked September 11, 2026. Retailer prices can change.Eight hundred lumens, nine watts, and a white range wider than most
Kasa's specification block gives 800 lm typical output at 9 W of actual draw, which the marketing rounds to a 60 W equivalent. Color temperature runs from 2500 K to 6500 K, the dimming range is 1 to 100 percent, the beam angle is 220 degrees, and the color rendering index is stated as 90 or higher. The base is E26 and the bulb is an A19 shape, so it drops into any ordinary US lamp socket.
The lower end of that white range is warmer than the 2700 K most fixed-white LED bulbs stop at, which matters for a bedside lamp, and the 6500 K top end is a cool daylight that suits a desk. The datasheet lists a slightly different 8.8 W draw and 8.8 kWh per 1000 hours of weighted consumption, and quotes standby power under 0.2 W on the page, so a bulb left switched on but dark costs very little.
Every adjustment runs through the app and the cloud
Three rows of Kasa's technical specifications carry the same qualifier: dimmable, tunable and color changing are each marked as yes, via app and cloud only. The datasheet is blunter, stating that the bulb is not compatible with regular light switches, should not be used with standard dimmers, and does not work with photosensors, motion sensors or timers. In practice the wall switch stays on and the phone or a voice assistant does the switching.
The consequence is that anyone who walks into the room and flips the switch off has disconnected the bulb from the network until it is powered again, at which point it comes back at whatever state the firmware restores. Households that mix smart and plain bulbs on one circuit run into this constantly. A smart switch or a plug on the fixture's circuit avoids the problem, and Kasa sells both, but the bulb on its own does not.
No Matter, so no Apple Home and no local fallback
Neither Kasa's page nor the V4.6 datasheet mentions Matter. Voice control is listed for Amazon Alexa, Google Assistant and SmartThings, setup is through the Kasa app on iOS 10 or Android 5.0 and newer, and the datasheet adds that a free Kasa account is required. Apple Home is absent from every list, and there is no commissioning code to scan in a third-party app.
For a household on Alexa or Google Home this changes little day to day. What it changes is the long term: a Matter device controlled by a local hub keeps working if the maker's cloud is switched off, while this bulb's dimming and color depend on TP-Link's servers staying up and its account system staying open. The KP125M plug from the same brand is Matter-certified, so the omission here is a product decision, not a company-wide one.
A lifespan stated in years, a warranty stated in years, and three fixture rules
The datasheet does not print an hours figure. It states that the bulb provides stable lighting for up to 22.8 years, footnoted as based on three hours a day, which works out to roughly 25,000 hours by our arithmetic, alongside a stated 15,000 switching cycles. Kasa's page lists a warranty term of two years for the US, longer than many bulbs at this price carry and easy to verify because it sits in the technical specifications block.
The fixture rules are the part buyers skip. The datasheet says the bulb is not for use in totally enclosed or recessed luminaires, is for indoor use only, is suitable for damp locations, and is not for emergency lighting. Heat is the reason for the enclosure rule, since a Wi-Fi radio and driver electronics inside a sealed fixture run hotter than the bulb is rated for, and running it there is the most common way to shorten the life the datasheet promises.
Kasa prints no price, so the pack you pick sets the cost
Kasa's page offers the bulb as a single, a 2-pack, a 4-pack and a 5-pack, but prints no price for any of them; the two buy buttons go to Amazon listings. When we checked, the 2-pack KL125P2 was $19.99, shown as $10.00 per bulb, and the 4-pack KL125P4 was $25.57 against a $34.99 list price, or $6.39 per bulb. Both were shipped and sold by Amazon.com.
The gap between $10.00 and $6.39 per bulb is large enough that the 4-pack is the sensible order for anyone planning more than two bulbs, and the 2-pack listing was itself marked as a deal, so the standing price may be higher. We did not find a single-bulb price anywhere on Kasa's site. Two small discrepancies are worth knowing: the page lists FCC and UL marks while the datasheet lists FCC, IC, ETL, RoHS, DOE and CEC Title 20, and the two documents give different weights and heights for the same bulb.
When to skip it
Skip it if the fixture is a sealed ceiling can, a recessed downlight or an outdoor lantern, because the datasheet rules out all three. Skip it if the room's wall switch is the way people actually turn lights off, since each flip takes the bulb offline until power returns. And skip it if your home runs on Apple Home or a local Matter hub, because the bulb offers no path into either.
It is a fair buy at $6.39 per bulb for table lamps and open fixtures in an Alexa, Google or SmartThings household that already keeps a Kasa account for plugs or switches. The two years of coverage and the 2500 K to 6500 K range are real advantages over the cheapest color bulbs; the cloud dependency and the missing Matter support are the price paid for them.
How we put this together
Built from the product pages and listings below, without test scores or results we have not measured. Specifications and prices change, so check the original page for the exact model, current price, delivery, and returns.
- Kasa: Kasa Smart Light Bulb, Multicolor, KL125 (opens in a new tab)
- TP-Link: KL125(US) V4.6 datasheet (PDF) (opens in a new tab)
- Amazon: Kasa Smart Light Bulbs 2-Pack, KL125P2 (opens in a new tab)
- Amazon: Kasa Multicolor Dimmable Wi-Fi Smart Bulb 4-Pack, KL125P4 (opens in a new tab)
- TP-Link: KL125 support and download page (opens in a new tab)
