Shop for anything in the recovery world and you'll run into a wall of numbers: 660 nm, 850 nm, "full spectrum," "far-infrared." It can feel like you need a physics degree to buy a light pad or a sauna. You don't. Once you know where each type of light sits and what it does in a device, the labels start making sense fast. Here's a chill, plain-language guide.
The quick version
All of these are forms of light, sorted by wavelength, which is usually measured in nanometers (nm) or microns (µm, where 1 µm equals 1,000 nm).
- Red light is visible. It's the deep red glow you see on a red light pad or panel.
- Near-infrared (NIR) sits just past red. You can't see it, but many red light devices pair it with red LEDs.
- Far-infrared (FIR) is much longer wavelength light that you mostly feel as warmth. It's what heats the panels in a far-infrared sauna.
So "red light therapy" devices and "infrared saunas" are related on the spectrum, but they're built to do pretty different jobs.
Where red light sits on the spectrum
According to NASA, the human eye can typically detect wavelengths from about 380 to 700 nanometers, with violet at the short end and red at the long end, around 700 nm.
Most home red light devices use red LEDs near the top of that range. A few examples from what we carry:
- The Illuminate Red V2 panel ($2,295.00) uses 1,980 micro-LEDs at 660 nm, per its maker.
- The Novaa Light Pad ($349.90) lists 660 nm red alongside 850 nm near-infrared.
Because 660 nm is visible, you'll see a strong red glow during a session. That's normal, and it's also why makers recommend protecting your eyes.
What near-infrared means
Go past about 700 nm and you leave visible light behind. That next stretch is near-infrared. You use it every day without thinking about it: NASA notes that a typical TV remote uses infrared at a wavelength around 940 nanometers (NASA).
In red light devices, the most common near-infrared wavelength you'll see listed is around 850 nm. A few examples:
| Device | Price at Sauna Chiller | Listed wavelengths |
|---|---|---|
| Novaa Light Pad | $349.90 | 660 nm red + 850 nm NIR |
| Novaa Deep Healing Pad XL | $599.90 | 400 red LEDs (660 nm) + 800 NIR LEDs (850 nm) |
| Novaa Recovery Pod | $2,500.00 | 2,320 LEDs, 660 nm red + 850 nm NIR |
| Novaa Extra-Strength Healing Laser | $299.90 | 16 lasers, 650 nm red + 808 nm NIR |
| Illuminate Red V2 panel | $2,295.00 | 660 nm red |
Prices and specs are as listed on saunachiller.com at the time of writing.
Why do so many devices combine red and near-infrared?
The research field behind these devices is called photobiomodulation, and it studies red and near-infrared light together. A review by Michael Hamblin of the Wellman Center for Photomedicine describes photobiomodulation as "the use of red and near-infrared light," with research focused on how cells, especially mitochondria, absorb that light (Hamblin, AIMS Biophysics, 2017). That's a big part of why makers build pads with both wavelengths in one device.
One practical note: since you can't see near-infrared, a pad's NIR LEDs can look dim or off even while they're working. That's expected, not a defect.
What far-infrared means (and why your sauna is different)
Far-infrared is a lot further down the spectrum. A review by Vatansever and Hamblin defines far-infrared as wavelengths from 3 to 100 µm, which is 3,000 to 100,000 nm (Photonics and Lasers in Medicine, 2012). The same review notes that specialty lamps and saunas deliver far-infrared for its effects on the body.
You don't see far-infrared. You feel it as radiant warmth, a bit like sitting in sunshine on a cool Tahoe afternoon. That's the heat source in a far-infrared sauna:
- The Orivon Lumin One ($6,999.00) is a 1-person Canadian hemlock cabin with 2 far-infrared heating panels.
- The Orivon Lumin Two ($7,999.00) is a 2-person cabin with 3 far-infrared panels.
- The Orivon Lumin Three ($9,999.00) is the 3-person version.
A far-infrared sauna is a heat session. A red light pad is a light session. They aren't swaps for each other, and a far-infrared sauna isn't a red light therapy device.
And traditional saunas?
A traditional sauna, like the Orivon Auris One outdoor cedar sauna ($15,999.00), heats the air with a heater, rather than using infrared panels to warm you directly. A systematic review of regular dry sauna bathing gathered research on both traditional and infrared sauna use (Hussain and Cohen, 2018) if you want to dig into what's been studied. Curious about cost? We broke down what it costs to run an infrared sauna.
How to read a spec sheet without overthinking it
When you're comparing devices, here's what's worth checking:
- The actual wavelengths. Look for real numbers like 660 nm or 850 nm, not just "red" or "infrared."
- Red only, or red plus NIR. Both exist. Decide whether you want a combined device or a single-wavelength one.
- Form factor. A flexible pad wraps a knee or shoulder, a panel covers more area from a distance, and a pod covers the whole body. Our wrap vs. pad guide for back use walks through that choice.
- Session time. Higher-output devices often list shorter sessions. See how often to use red light therapy and for how long for maker session times.
- Heat vs. light. If what you really want is a deep sweat, you're shopping for a sauna, not a light pad.
Be a little skeptical of a vague "full spectrum" label with no numbers behind it. A clear spec sheet is a good sign.
Safety basics
The Cleveland Clinic says red light therapy appears to be safe when used short-term and as directed, recommends protecting your eyes with at-home devices, and notes that long-term safety isn't known yet. Follow your device's manual, and check with your doctor first if you're pregnant, take photosensitizing medication, or have a medical condition.
FAQ
Is near-infrared the same as red light?
No. Red light is visible and sits around the top of the visible range, near 700 nm. Near-infrared starts just past that and is invisible. Many devices, like the Novaa Light Pad, combine 660 nm red with 850 nm near-infrared.
Is an infrared sauna the same as red light therapy?
No. A far-infrared sauna uses far-infrared panels, which are much longer wavelengths (3 to 100 µm), to warm you up. Red light devices use visible red and often near-infrared LEDs. Many people use both, but they're different sessions.
Why can't I see the near-infrared LEDs working?
Near-infrared is outside what the human eye can detect, so those LEDs can look dim or dark while they're on. That's normal.
What wavelength should I look for?
Many home red light devices list 660 nm red, and combined devices often add 850 nm near-infrared. The most useful thing is a clear spec sheet with real numbers, plus a form factor and session time that fit your routine.
This article is for general information only and is not medical advice. Red light devices and saunas are wellness products and aren't intended to diagnose, treat, cure or prevent any disease, so check with your doctor first, especially if you're pregnant, photosensitive or managing a medical condition.
Sources - NASA Science, Visible Light and Infrared Waves - Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 2017;4(3):337–361. - Vatansever F, Hamblin MR. Far infrared radiation (FIR): its biological effects and medical applications. Photonics Lasers Med. 2012;4:255–266. - Hussain J, Cohen M. Clinical effects of regular dry sauna bathing: a systematic review. Evid Based Complement Alternat Med. 2018. - Cleveland Clinic, Red Light Therapy - Product specifications as listed on saunachiller.com