Petzl Nao Running Headtorch Review

The Nao is part of Petzls Performance Series of head torches and features a powerful 575 lumen beam with reactive lighting technology which automatically adjusts brightness and beam pattern depending on your environment.

I had entered my first 100 mile ultra and I expected to be running through most, if not all, of the night so I was looking for a headtorch which did 2 things:

1. had a long battery life to get through the night
2. had a good quality wide beam that would allow me to concentrate on running rather then looking where I was going

After much searching and research I finally decided on the Petzl Nao but did it live up to expectations?

Reactive Lighting Technology

Reactive Lighting is what Petzl calls this headtorches ability to adjust the brightness of it’s beam depending on your environment in order to save battery life.

A sensor detects the amount of light that is reflected off objects in the torches path and regulates the beam automatically between 7 to 575 lumens. The idea is that when you need full beam, the torch gives you full beam yet when you don’t the torch will give you what it deems to be the correct amoutn

For example: imagine you are running through a dark forest where you need the full beam, Reactive Lighting senses the light levels around you and provides you with the maximum brightness.

Now imagine you leave the forest and need to run through a village with street lights as part of the route. Obviously you don’t need full beam here so Reactive Lighting senses the increased light levels around you and adjusts the beam accordingly to increase battery life.

It’s a simple yet clever idea that for the most part does work very well however in a few situations it can become confused and start strobing, just like being in a disco.

If you look at a reflective road sign or another runners reflective kit it can cause the beam to dim and if it is cold and you have condensation in your breath then you can cause the beam to flicker considerably if the light bounces off the water droplets and gets picked up by the sensor.

This really is a minor issue with what is overall a welcome addition to the headlamp and if it does annoy you that much then all you need to do is turn the headlamp to constant lighting.

The table below from the Petzl website shows how the torch will behave at different factory presets. These can be altered with the handy Petzl application.

Lighting technologyLighting modesBrightnessDistanceBurn timeReserve mode
REACTIVE LIGHTINGMax autonomy7 to 290 lm2 to 80 maround 12 h 30 – 52 h max1 h at 20 lm
Max power7 to 575 lm2 to 135 maround 6 h 30 – 52 h max
CONSTANT LIGHTINGproximity120 lm60 m8 h
rapid movement430 lm130 m1 h 30


Obviously the battery life is extended thanks to Reactive Lighting talked about previously and Petzl have done well to put a lot of power into a small battery which as a result feels very light and balances well on your head.

The battery has a set of 3 lights which indicate power level left, although you do have to take the torch off to see this so isn’t much use while running.

The battery is rechargable via a USB charger making recharging simple.

One thing that is a small problem is the way the battery release mechanism works. It’s a small clip that can be fiddly to release at the best of times never mind with cold hands or when wearing gloves.

It’s only a minor issue and in most cases isn’t a problem but i’m sure there would be an easier way to do this. Maybe something for Petzl to look into in the future.


The Petzl Nao really is an impressive headtorch and brightness levels are more than adequate when running at speed across uneven terrain.

For trail finding the lamp is perfect. the light is even over distance and is very powerful.


Unlike most head torches the headband of the Nao is adjusted by a simple draw cord that works very well and performs much better than the elasticated version found on most other headtorches.

It allows you to fasten the torch securely to your head and even without any padding on both the torch and battery I find it to be incredibly comfortable after its adjusted correctly.

When running the headtorch doesn’t move around or bounce thanks to it’s fastening mechanism although you do get a nice torch imprint once you remove it.

Despite it’s weight the Petzl Nao is very comfortable to wear for long periods without issue. I have heard of other people thinking comfort could be improved by the addition of a piece of foam to provide some additional cushioning but I didn’t find this to be an issue.


Weighing 190 grams (6.7 ounces) the Nao is one of the heaviest headlamps on the market but this weight is distributed and carried well thanks to its unique headband.

Once the headtorch is on and you have it adjusted this weight doesn’t detract from the overall performance. In fact I find this more comfortable to use than the single unit Petzl Tikka headlamp which I was previously using because it feels more secure and stable when running.

Best uses

This is a head torch for the serious trail or ultra marathon runner who expects to spend long periods out in the dark of the night and needs a dependable headtorch to provide them with a high quality beam and good battery life.


Without a doubt the Petzl Nao is a fantastic bit of kit and if it meets your requirements you won’t do any better. It’s not for runners a budget looking to illuminate the road in front of them when out for a couple of miles round town.

If you are doing a long ultra and expect to be out most the night then this is the perfect head torch for your needs and it certainly justifies the cost in these instances.

The beam pattern is confidence inspiring and the battery life will last you through all but the longest of nights.

Reactive lighting technology is a good feature which helps to improve battery life once you get past the few little niggles that come with it, but on the whole is a welcome addition to this headtorch.

It is a heavy torch but this is almost impossible to notice once you have it on your head and adjusted correctly. In fact I find it more comfortable to wear than other lighter headtorches I own.

So the bottom line on the Petzl Nao is if it matches your requirements go and buy one, you won’t regret it!

Buy Petzl Nao online

AmazonFrom £98.90FreeBuy now
WiggleFrom £108.75FreeBuy now

Manufacturers specification

REACTIVE LIGHTING mode: brightness adapts instantly to need, due to the light sensor. The lamp offers adapted, comfortable lighting. It helps keep the hands as free as possible and optimizes management of the energy source.

Maximum brightness: 575 lumens

Lithium-Ion rechargeable battery:

  • performs well at low temperatures
  • easily rechargeable with the integrated USB connector (compatible with all USB chargers: cell phone, MP3 player, computer, portable energy source, solar panel, car cigarette lighter…)
  • with battery charge indicator light
  • can be replaced, if necessary, with two AAA/LR03 batteries (reduced performance)

CONSTANT LIGHTING mode is also available, guaranteeing stable lighting that does not diminish during the entire chosen burn time

Two lighting levels available:

MAX POWER – brightness prioritized
MAX AUTONOMY – burn time prioritized

Lock function to avoid accidentally turning it on during transit or storage

Headlamp is stable on the head: adjustable headband with top strap for technical activities

Optional belt kit for NAO allows the rechargeable battery to be moved to the belt to reduce the weight worn on the head, or to keep it warm in winter

Customized lighting with OS by Petzl software, free for download at


  • Weight: 187 g
  • Beam pattern: wide, mixed
  • Energy: Lithium-Ion 2600 mAh rechargeable battery (included) or 2 AAA/LR03 batteries (not included)
  • Recharge time: 5 h
  • Battery compatibility: alkaline and lithium
  • Watertightness: IP X4 (weather resistant)
  • Certification(s): CE
  • Headlamp comes with rechargeable Lithium-Ion battery and 30 cm USB cable

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