If you’ve ever had to swap out a turn signal or tail light, you might have noticed terms like “7443 bulb” or “7440 bulb.” The 7440 and 7443 bulbs are some of the most versatile automotive bulbs out there. They are commonly used in vehicles from Honda, Chevrolet, Scion, Volkswagen, Toyota, and many others. Whether it’s a rear turn signal or a brake light, chances are you’ll encounter one of these bulbs.

This guide breaks down what these bulbs are, how they’re used, and how to pick the right one for your car.

Also read: 7443 vs. 3157: the Key Differences

what are 7443 7440 bulbs

What Is Bulb Compatibility for 7443 and 7440 Bulbs?

The 7443 bulb is a dual-filament bulb commonly compatible with other bulbs like the 7440, 7441, 7444NA, 992, W21W, and WY21W. However, it is not interchangeable with the single-filament 7440 in all cases, as it requires the correct socket (standard or CK), and a load resistor or flash relay might be needed to prevent "hyper flashing" when replacing with an LED bulb for turn signals.

A 7440 bulb's common compatibility includes other single-filament wedge base bulbs like 7441, T20, W21W, and WY21W. It's crucial to note that the 7440 is a single-filament bulb, making it incompatible for applications requiring a dual-filament bulb, such as some brake or tail light combinations that use a 7443.

Always double-check your vehicle’s manual or use an automotive bulb finder before swapping bulbs to avoid any mishaps.

Many LED bulbs are made to be versatile. 7443 7440 LED bulbs from SEALIGHT like this product can fit 992, 7440, 7441, 7443, 7442, 7444, W21W, WY21W, 7440NA, 7440NAK, 7444NA, 7444NAK bulb sockets.

This broad compatibility allows for easy upgrades across various vehicle models and applications, such as tail lights, brake lights, turn signals, and reverse lights.

What Is the Base Type of 7443 and 7440 Bulbs?

Both the 7443 and 7440 bulbs use the W21W base family, but there’s a key difference. The 7443 uses a W3×16q base for its dual filaments, while the 7440 uses a W3×16d base for its single filament. This detail is crucial for ensuring a snug, proper fit in your car’s socket.

What Are the Types of 7443 and 7440 Bulbs?

When replacing bulbs, you’ll usually choose between traditional halogen or modern LED options. Halogen bulbs have been around forever. They’re affordable and dependable, though they don’t last as long and draw more power. LEDs, on the other hand, offer brighter, faster illumination, use less energy, and can last decades with proper use.

Halogen bulbs usually last 1,000–2,000 hours, while high-performance LEDs can go up to 50,000 hours. That’s a big difference, especially if you’re tired of constantly swapping bulbs. Plus, LEDs stay bright throughout their lifespan, while halogens can fade over time.

Brands like SEALIGHT provide plug-and-play 7443 7440 LED upgrades for most vehicles, making the swap simple and effective.

What Is the Lifespan of a 7443 and 7440 Bulb?

The 7443 or 7440 halogen bulbs generally give you 1,000–2,000 hours of use, depending on quality and how often you drive. LED bulbs can last up to 50,000 hours. Beyond just longevity, LEDs maintain consistent brightness throughout their life, so your signals and brake lights won’t gradually dim.

What Are the Different Colors Available for 7443 and 7440 Bulbs?

Color matters when it comes to vehicle lighting. White or clear bulbs are common for backup lights or DRLs, amber/yellow is standard for turn signals and side markers, and red is required for tail and brake lights.

7443 or 7440 halogens usually come in clear or amber, and you might need filters or lenses to tweak the color. While 7443 7440 LED bulbs come in various colors, including white/clear, amber/yellow, red.

What Is the Light Output of a 7443 and 7440 Bulb?

Standard halogens give enough light for everyday driving, usually in the 280–400 lumen range. LEDs can push past 1800 lumens, delivering faster, brighter illumination. This helps enhance the looks and brightness. Better light output means quicker response time, thus can literally improve road safety.

What Is the Voltage of a 7443 and 7440 Bulb?

Most cars run on 12V systems, and these bulbs are designed accordingly. A halogen 7440 draws 21 watts, while a 7443 uses 21/5 watts for its dual functions. LED versions use far less power while often producing more light, which reduces strain on your car’s electrical system.

Should You Upgrade to 7443, 7440 LED Bulbs?

Yes, LEDs are worth the upgrade.

LEDs outshine halogens in brightness and coverage, with a quality 7443 LED bulb putting out up to 1800 lumens and offering full 360-degree illumination. That makes your car easier to see and helps you spot hazards sooner, especially at night or in bad weather.

LEDs also use far less power than halogens while giving off stronger light, which reduces strain on your battery and alternator. On top of that, LEDs last much longer—up to 50,000 hours—so you won’t have to replace bulbs as often, saving both time and money.

Another advantage is speed: LEDs illuminate instantly, unlike halogens, which makes brake lights and turn signals more effective and gives other drivers more time to react.

Beyond performance, they give your car a modern, polished look.

Where to Buy 7443 and 7440 LED Bulbs

If you want reliable, high-performance LED bulbs, stick with trusted brands like SEALIGHT. We cover nearly every automotive lighting need, from headlights to tail, brake, turn signals, and interior lights. SEALIGHT offers straightforward installation, strong compatibility, and solid support.

With SEALIGHT, upgrading your car’s lighting is straightforward, reliable, and long-lasting. Shop SEALIGHT 7443 and 7440 LED Bulbs now!

Best 7443 7440 LED Bulbs Recommended

Check out the most popular 7443 7440 LED bulbs from SEALIGHT: