How we score
Every device gets a 0–10 score computed from official specs — the same formula, the same inputs, for every model. This page is the whole method.
LED light therapy masks
The formula
Each metric is min-max normalized across the 7 models we track:
(value − min) / (max − min). Session time is inverted, so shorter scores
higher. The score is ten times the weighted sum:
score = 10 × (0.25·wavelengths + 0.20·LED count + 0.15·irradiance + 0.10·session time + 0.10·cordless + 0.10·FDA status + 0.10·warranty)
| Metric | Weight | Direction | Why it matters |
|---|---|---|---|
| Wavelengths covered (count of clinically used bands) | 25% | Higher is better | Blue (~415nm), red (~633nm) and near-infrared (~830nm) are the bands brands cite most; more bands, more use cases. |
| LED count | 20% | Higher is better | More emitters means more even coverage across the face. |
| Irradiance (mW/cm²) | 15% | Higher is better | The power behind each session, as stated by the brand. |
| Session time (min) | 10% | Lower is better | Whether you'll actually keep the habit. |
| Cordless operation | 10% | Yes beats no | A mask you can walk around in gets used more. |
| FDA-cleared status (as stated by the brand) | 10% | Yes beats no | We relay the manufacturer's own regulatory statement, nothing more. |
| Warranty (months) | 10% | Higher is better | How long the brand stands behind the device. |
When a model is missing a metric it is scored on the specs it has, with the remaining weights rescaled to sum to one — missing is never treated as zero, and the formula never guesses.
Worked example
Run the numbers yourself
The current top scorer, Shark CryoGlow LED Face Mask (FW312):
| Metric | Raw value | Normalized | Weight | Points |
|---|---|---|---|---|
| Wavelength coverage | 3 | 0.500 | 25% | 1.25 |
| LED count | 480 LEDs | 0.935 | 20% | 1.87 |
| Published irradiance | 128 mW/cm2 | 1.000 | 15% | 1.50 |
| Session length (shorter is easier) | 6 min | 0.667 | 10% | 0.67 |
| Cordless design | yes | 0.500 | 10% | 0.50 |
| FDA status (brand-stated) | yes | 0.500 | 10% | 0.50 |
| Warranty | 24 mo | 1.000 | 10% | 1.00 |
| Total | 7.3 |
Other categories
Same method, different dials
IPL hair removal devices and at-home nail equipment use the same min-max method with category-specific metrics and weights:
| Category | Weights | |
|---|---|---|
| IPL hair removal | Flash count 25% · energy density (J/cm²) 25% · skin-tone sensor 15% · treatment window (cm²) 15% · intensity levels 10% · corded/cordless 10% | launching next |
| Nail lamps & kits | Lamp power (W) 30% · LED beads 20% · timer modes 15% · full-hand fit 15% · cordless/battery 10% · warranty 10% | launching next |
| Gifts for her | Not scored. Jewelry and gift picks are editorial selections with full affiliate disclosure — there are no meaningful specs to rank. | launching next |
Data sources
Every spec comes from the manufacturer's official product page — never from retailer listings, reviews, or forums. Each product page links the exact source its numbers came from, so every figure is one click from verifiable.
Update cadence
Specs are re-verified against the official pages on a monthly cycle, and scores are recomputed the day any data point changes or a model enters or leaves the list. The footer of every page shows the last data update (currently 2026-09-10).
What we don't do
We don't lab-test. We don't review skin outcomes, and we never claim a device treats, cures, or prevents anything — where a brand states an FDA clearance or a clinical result, we link their statement rather than making our own. We don't show prices — we have no live price feed, so prices and availability are checked on Amazon. And we don't sell placement: no brand can pay to move a score, because the formula only reads specs.
How we make money
As an Amazon Associate we earn from qualifying purchases made through links on this site. Some links route through Awin, an affiliate network, on the same terms. Commissions come out of the retailer's pocket, not yours, and they never enter the formula — the math only sees specs.
Corrections
If a number here ever differs from the official brand page, the official page wins. Verified errors are fixed in the next update cycle. To flag one, email the corrections address published with our newsletter signup (launching soon) — until then, the official sources linked from every product page are the authoritative record.