Red Light vs. Near-Infrared: What the Wavelengths Mean

By Better Human Goods
2 min read

Shopping for a red light device, you'll keep running into two terms: red light and near-infrared, often listed with specific wavelength numbers. Here's what they mean, in plain language, so the spec sheets make sense.

It's all about wavelength

Light comes in different wavelengths, measured in nanometers (nm). Our eyes can only see a certain range. The differences between "red" and "near-infrared" come down to where on that scale the light sits.

Red light: the visible glow

Red light sits in the visible part of the spectrum — it's the warm red glow you actually see when a device is on. It's typically described in a range around the mid-600s nanometers. Because it's visible, it's the light most people picture when they think "red light therapy."

Near-infrared: the invisible part

Near-infrared (often shortened to NIR) sits just past visible red — a slightly longer wavelength your eyes can't detect, usually described in the higher range (around the 800s nm). A device emitting near-infrared may look dim or partly dark even while it's working, because much of the output is invisible.

Why devices often combine both

Many quality devices emit both red and near-infrared together. The simple buyer's takeaway: the two wavelengths reach differently, and a combined device gives you both in one session. What matters most when shopping is that the manufacturer states the specific wavelengths rather than just saying "red light."

How to read a spec sheet

  • Look for named wavelengths in nm (e.g., a red figure and a near-infrared figure).
  • Be wary of devices that only say "red light" with no numbers.
  • Combined red + near-infrared is common and gives you both bands.

The bottom line

Red light is the visible glow; near-infrared is the invisible band just beyond it. Many devices combine both. The real quality signal is whether the device is honest and specific about the wavelengths it emits.

Every device in the Red Light collection is built to a higher hardware standard, with clear specs. See Red Light devices →

Keep reading: Panel vs. mask vs. belt →  |  How and when to use it →

This article is general information, not medical advice.