LED Flicker Explained: Three Types and How to Avoid Them
Not all LED flicker is the same. There are three distinct types that can affect your lighting, and understanding each one will help you choose the right bulbs and set up your lights correctly.
Type 1: Invisible High-Frequency Flicker
This is the most common and least understood type of flicker. It happens inside the LED driver at 50-100 times per second (in line with Australia's 50Hz power supply), and you cannot see it with the naked eye.
Even though it's invisible, research has linked this type of flicker to:
- Eye strain and visual fatigue
- Headaches and migraines
- Difficulty concentrating
- Discomfort for people with photosensitivity, migraines or autism spectrum conditions
How LiquidLEDs bulbs compare:
Our bulbs are independently tested by TUV Rheinland to the EU Ecodesign Regulation 2019/2020, one of the world's strictest lighting standards:
| Metric | LiquidLEDs Result | Standard Limit | |---|---|---| | Flicker index | ≤1.0 | ≤1.0 | | Stroboscopic effect | ≤0.9 | ≤1.0 |
A stroboscopic effect score of ≤0.9 is at the very low end of what's achievable, meaning our bulbs produce near-zero perceptible flicker under normal use.
Who benefits most: Home offices, children's rooms, anyone prone to headaches, photographers and videographers shooting under artificial light.
Type 2: Dimmer Incompatibility Flicker
This type of flicker is visible and is caused by using an LED bulb with an incompatible dimmer switch. It appears as a noticeable buzz, flicker or strobe effect, especially at low dim levels.
Why it happens:
Most older dimmer switches were designed for incandescent or halogen bulbs, which have a much higher minimum load. LED bulbs draw very little power, which can confuse these dimmers and cause them to chop the power supply inconsistently.
How to fix it:
- Replace your dimmer with a modern LED-compatible trailing-edge dimmer
- Use LiquidLEDs' own Pixie Dimmer, which is specifically designed and tested with our bulbs
- If you prefer a third-party dimmer, look for one rated for low-load LED use (minimum load of 0W or 1W)
Signs this is your issue: The flicker only happens when the lights are dimmed, not at full brightness. It may also be accompanied by a buzzing sound from the bulb or the switch.
Type 3: Tariff-Switching Flicker (Australia)
This is a uniquely Australian issue that catches many people off guard. Australian electricity providers use a system called ripple control, which sends a signal through the power grid to switch certain loads (like hot water systems) between peak and off-peak tariffs. This signal causes a brief, momentary fluctuation in the mains voltage.
With standard LED bulbs, this voltage spike can cause a brief visible flicker, sometimes just a single flash, or a brief period of instability lasting a second or two. It most commonly happens in the early morning or evening when tariff periods change.
How to identify it:
- Flicker occurs at specific times of day (typically around 10pm, 11pm, or early morning depending on your provider)
- It affects all lights in your home simultaneously
- It does not happen when you use the dimmer
What you can do:
- LiquidLEDs bulbs with advanced flicker-filtering drivers are more resilient to these voltage spikes than standard LED bulbs
- If this is a persistent issue, speak to your electricity provider about the ripple control schedule for your area
- Installing a whole-home surge protector can also help buffer these transient spikes
Summary
| Flicker Type | Visible? | Cause | Solution | |---|---|---|---| | High-frequency (invisible) | No | LED driver technology | Choose TUV-certified flicker-free bulbs | | Dimmer incompatibility | Yes | Wrong dimmer type | Use an LED-compatible dimmer or Pixie Dimmer | | Tariff switching (AU) | Yes (brief) | Electricity grid ripple control | Flicker-filtering bulbs, surge protector |
LiquidLEDs Flicker-Free Range
Browse our full range of Flicker-Free LED bulbs at liquid-leds.com.
For a deeper dive, visit our Flicker-Free Lighting Guide.
Need Help?
Not sure which bulb or dimmer is right for your situation? Our team is happy to help. Contact us or call +61 2 8880 9033 (weekdays 8am-6pm AEDST).