🛈 If you buy through our links, Amazon pays us a small commission at no extra cost to you. That’s how we keep the database running. How we choose.
📑 Contents
⚡ The best W21/5W bulbs in stock
Stock checked on October 8, 2026
The best W21/5W bulbs in stock
SYLVANIA 7443 Long Life Miniature Bulb, Daytime Running Light, 2 Bulbs
SYLVANIA 7443 SilverStar Mini Bulb, Daytime Running Light, 2 Bulbs
2 Pack 7443 Bulb,7444 T20 W21/5W Brake/Tail/Turn Signal Light Bulbs.
12 Pack 7443 Bulb 7444 T20 W21/5W 7443LL Brake/Tail Light Bulbs/Turn Signal Long Life Daytime Running…
20 Pcs 7443 Brake Light Bulbs, T20 7444 7443LL W21/5W Turn Signal Bulbs
See more W21/5W bulbs on Amazon →
LuzCoche score: combines the average rating and the number of customer reviews on Amazon.
Cars that use a W21/5W bulb
We don’t have any cars with this bulb in our English database yet. Search for your car to see all its bulbs.
Which W21/5W to buy: standard, brighter or long life
- Standard: the classic incandescent bulb; cheap and no dashboard warnings.
- LED: whiter light and lower power draw. On turn signals and brake lights they can cause hyperflash or bulb-out warnings: choose CANbus versions or add load resistors.
- Long life: handy where bulbs are hard to reach (tail lights or dome lights).
To confirm which bulb each light on your car uses, follow the methods in how to find out which bulb your car takes.
Signal & interior bulbs
Frequently asked questions
What is a W21/5W bulb?
The W21/5W is a 21/5 W, 12 V automotive bulb with a W3x16q base. It’s also sold as 7443 and 580.
Is the W21/5W the same as the PSY24W?
No. Even if they look alike, each size has a different base (W3x16q on the W21/5W) and won’t fit another size’s socket. Always buy the exact size your car takes.
Can I replace a W21/5W with an LED?
Yes, LEDs are common for turn signals, parking, license plate and dome lights. Pick CANbus versions or use load resistors to avoid hyperflash and bulb-out warnings, and keep the correct color (amber for turn signals, red for brake lights).