Here is how these two headlamps compare on the numbers. They score within a hair of each other, so it comes down to the details below.
| Petzl Swift LT | Black Diamond Deploy 325 | |
|---|---|---|
| GearScore | 79✓ | 79 |
| Max lumens | 380 lm✓ | 325 lm |
| Weight | 1.5 oz | 1.3 oz✓ |
| Beam distance | 70 m✓ | 52 m |
| Max runtime | 60 h | 30 h |
| Price | $55✓ | $70 |
| Battery | Rechargeable | Rechargeable |
| Water rating | IPX4 | IPX4 |
Highlighted cells mark the better spec: Swift LT in blue, Deploy 325 in amber. A blank spec is never counted as a win. Runtime is shown for context and is not scored, since makers publish it at different brightness levels. GearScore is the overall rating (0 to 100); re-weight it on the full headlamp comparison. Prices are current MSRP.
The Petzl Swift LT against the Black Diamond Deploy 325 is a study in priorities. They are close enough that this really is about which handful of specs you weight most.
The Swift LT is brighter (380 vs 325 lm), a longer beam (70 vs 52 m), and $15 cheaper. The Deploy 325 is 5 g lighter. Their GearScores land within a couple of points (79 vs 79), so neither runs away with it.
Pick the Swift LT if you care most about brightness and longer throw, which makes it the better call for your priorities. Pick the Deploy 325 if low weight matter more to you, or you are focused on counting grams on long miles.
The Petzl Swift LT. It is brighter (380 vs 325 lm) than the Deploy 325.
The Black Diamond Deploy 325. It is 5 g lighter than the Swift LT.
They are nearly tied at 79 and 79 on the default algorithm, so re-weight the score to your own priorities to break the tie.
It depends on your priorities. Go with the Swift LT for brightness, or the Deploy 325 for low weight. The spec table above shows exactly where each wins.