TP-Link Kasa Filament Smart Bulb review: Models KL50 and KL60 both deliver quality light, but neither is very bright

In the smart lighting space, vintage-style filaments are fully on trend for 2020, and just about every vendor seems to be releasing bulbs with visible, elongated LEDs that approximate the look of an old-time Edison bulb.

TP-Link is the latest to the party with its matched pair of Kasa Smart Vintage LED Filament Bulbs, both of which are affordable Wi-Fi-ready devices, albeit rather limited in features.

This review is part of TechHive’s coverage of the best LED bulbs. Click that link to read reviews of competing products, along with a buyer’s guide to the features you should consider when shopping.

Christopher Null / IDG

These bulbs are both white-only and each comes permanently tuned to a specific color temperature: The KL50 is a soft (but still warm) white, the KL60 is an even warmer amber. Aside from that, they are largely distinguished by their overall power.

The KL50 emits 600 lumens, but the KL60 puts out just 400. Both of those values are rather low, however, making these bulbs best suited for accent use rather than full-on task lights. Both bulbs can be dimmed in software—and with either Amazon Alexa or Google Assistant—but not via a hardware switch.

Both bulbs also have the same basic form factor, with a traditional globe set atop a somewhat chunky base containing the electronics and heat sink. Since these bulbs are designed to be used in a setting where they aren’t obscured, you’ll probably want to check them out in depth to ensure their aesthetic works with your home, before you purchase them in bulk.

Let’s look at each bulb in turn.

Kasa Filament smart bulb, soft white

TP-Link

The KL50 is tuned to 2700K, which in most environments will feel very warm and cozy. Its 600 lumens require just 7 watts of power. The bulb is made from clear glass, unfrosted, with a white base that will be rather visible in some fixtures. The crisscrossed filament design is interesting, but unusual for an exposed-filament style bulb.

Connection to the bulb takes place through Kasa’s mobile app, which is functional but comparably basic. A now archaic setup operation requires manually connecting to the bulb’s temporary Wi-Fi network and pairing it to your own; Kasa hasn’t jumped on newer automation techniques—nor Bluetooth—just yet.

Inside the app, functionality is as expected, with four easy-to-reach brightness presets and a dimmer wheel if you want to fine-tune things. It also includes various goodies, including a capable scheduling system (including sunrise/sunset options) and an energy-usage meter. The app is generally quite responsive and changes are pushed to the bulb nearly instantaneously.

The bulb’s light quality is solid, but the lack of luminosity may present a challenge for some. At $17 each, the bulb is also just slightly expensive versus competing products with a similar design and feature set, but not exorbitantly so. While another few hundred lumens would be nice, it’s a capable enough bulb to at least merit putting it on the consideration list if its specific features are on your shopping list.

Kasa Filament smart bulb, warm amber

TP-Link

As noted above, the KL60 bulb has the same overall form factor as the KL50, but it differs in a few key ways. First, the bulb glass is given a light amber sheen, which provides it with an antique appearance, particularly when paired with the bronze-colored heat/sink base. The filaments in this bulb are largely vertical and are more readily visible to the naked eye than those in the KL50.

If the KL50 is a warm bulb, the KL60 is downright hot. Tuned to a very low 2000K, its light is extremely orange in hue, approximating candlelight. With just 400 lumens (and a 5.5-watt power draw) of brightness, it frankly feels a lot like candlelight.

Setup and operation are identical with the KL60—to the point where you’ll need to pay attention to the name you give the bulb in order to distinguish it from any other Kasa bulbs. Again, that means you have full control over dimming, but no tuning features. Scheduling and energy monitoring features work the same way as they do on the KL50.

All told, choosing this bulb over the KL50 really comes down to the question of color temperature and power. While the KL60 can serve as a bedside bulb in some scenarios, I didn’t find the KL50 bright enough to read by at night. It is, however, pretty enough to look at.