
Roundup
The Best Grow Lights
The main ranking: nine fixtures sorted on published data, with every gap named.
We have not tested any of these units. What we have done is read every published spec sheet, divide the figures against each other, and report what the manufacturer left out.

Every other site in this category says it tested twenty grow lights. We have tested none, and we say so at the top of every page. What we do instead is a job that is genuinely useful and that nobody else seems to bother with: read every specification a manufacturer publishes, divide the figures against each other, and report exactly what is missing.
That turns out to be more revealing than it sounds. Of the nine fixtures in this section:
That distribution is the single most useful thing we can tell you about this category, and it is invisible from any individual product page.
| We can tell you | We cannot tell you |
|---|---|
| Published photon output, and whether it divides correctly against the published wattage | Whether the fixture actually delivers its published output |
| Computed average PPFD over a stated area, with the arithmetic shown | Real PPFD at any point, which needs a meter and the unit in hand |
| Computed running cost from published wattage at your tariff | Whether the driver runs hot, buzzes, or fails in year three |
| Whether the form factor suits your shelf geometry | Build quality, fit and finish, or how the mounting hardware feels |
| Exactly which specifications a manufacturer declines to publish | Why they decline to publish them |
Diodes, driver and dimming, roughly in that order. Fixtures naming Samsung LM301H or Bridgelux diodes cluster at the efficient end. Dimming adds cost and is genuinely worth it if the fixture will ever sit over young seedlings. Beyond that, a substantial part of the price spread in this category is appearance — a pendant that belongs in a living room costs several times a bar of equivalent output and is usually less efficient.
Trusting a review that claims hands-on testing without publishing a method. If a review says a fixture measured a given PPFD, it should say which meter, at what height, at what point in the footprint, and with what else in the room. Reviews that skip all four are asserting, not measuring — and the assertion is unfalsifiable, which is precisely what makes it worthless.
Our full method, including every formula and every assumption, is on the methodology page.
Each of these names a top pick and links straight out to it. Prices come from the live price layer, which is why they read “check price” rather than showing a figure we cannot verify at the moment you load the page.

Roundup
The main ranking: nine fixtures sorted on published data, with every gap named.

Roundup
The 100 W panel class compared on published output, efficacy and internal consistency.

Roundup
Linear fixtures for shelves and trays, and the disclosure gap running through the category.

Roundup
Screw-in fixtures for single plants, what the form factor costs, and how to place one.

Comparison
Two panels in the same segment: one publishes photon data, the other publishes none.

Comparison
A 4 ft strip against a screw-in bulb: different shapes, different data, different jobs.

Guide
How the retail channels differ, and why the spec sheet is rarely on the listing.

Guide
A diagnostic checklist for failing fixtures and for plants that say something is wrong.

Review
343 µmol/s published at 150 W. The most photons here, and the numbers are checkable.

Review
249.21 µmol/s from 100 W, and a 2.5 µmol/J claim that divides out correctly.

Review
2.7 µmol/J on Samsung LM301H, and a PPFD claim with no measurement distance.

Review
Useful features, zero published photon data. What you can and cannot know before buying.

Review
2.75 µmol/J published, with no PPF to check it against. The trade-off, examined.

Review
The default shelf bar. Correct form factor, unbeatable price per foot, zero published output.

Review
65.6 µmol/s and a PPFD at a stated 1 ft — enough to place it by arithmetic.

Review
A living-room pendant with genuinely usable placement data and the lowest efficacy here.

Review
A 10 W clip lamp with a repeating timer, and no manufacturer spec sheet to check.