We've put 10 front bike lights and seven rear bike lights through their paces in our bike light group test.
We tested bike lights from popular retailers Halfords, Lezyne, Knog, Moon, Cateye and more. These were then dropped, soaked in water, and put through their paces on roads at night, to reveal those that shone out. Four were good enough to be named Which? Best Buys.
It's a legal requirement to have a white front light and red rear light on display when you're cycling at night. You will also be, and feel, a lot safer on the roads with a good front and rear bike light on your bike.
All of the bike lights we selected for testing are USB rechargeable. They're also all designed to illuminate the road in front of you, as well as be seen by other road users.
Last tested: October 2020. Prices and availability last checked 6 June 2022.
Only Which? members can view the bike light test results below. If you're not yet a member, you'll see an alphabetically ordered list of the bike lights we tested. to get instant access to our test scores and Best Buy recommendations below.
Key features: 800 Lumen, up to 12 hours battery, five light settings between 800 and 200 Lumen, Micro USB cable to recharge
This 800 Lumen front light can be attached to a helmet or your front handlebars. Blackburn says it will survive being dropped from up to a metre, it takes four hours to recharge and will last up to 12 hours on its strobe setting.
It's pretty light for a bike light, but how did it cope when we dropped it from the height of a set of handlebars, and how well does it really light up the road compared with the other lights we tested?
Key features: 800 Lumen, up to 30 hours battery life, 3 hours to recharge, five light settings between 800 and 200 lumen, USB rechargeable
The Cateye Ampp 800 has a FlexTight bracket which tightens on your bars with the twist of a dial. The light can be removed quickly from the mount if you don't want to leave it stored on the bike. Cateye says it takes three hours to charge and will last for up to 30 hours on its least bright setting.
The mount takes a little longer than some to attach to the bike, but how easy is it to switch between settings, will it survive a heavy rain shower and can you get a brighter light for less?
Key features: 1,000 lumen, aero adaptor attachment, up to 96 hour battery life on lowest setting, remaining burn time display, various rubber mounts to secure a tight grip to your bars, doubles up as a powerbank, USB rechargeable
This Halfords own-brand front bike light claims to dish out a whopping 1,000 Lumen, and it also comes with an optional aero mount so the light will sit out in front of your handlebars. This light also doubles up as a powerbank, so you can charge your phone, or your rear lights if you need to.
It's a potentially appealing package for only £40. But can a Halfords own brand really put specialist lighting brands like Lezyne, Knog and Cateye to the sword?
Key features: 1,600 lumen, aero adaptor attachment, up to 136 hour battery life on lowest setting, remaining burn time display, various rubber mounts to secure a tight grip to your bars, doubles up as a powerbank, USB rechargeable
If the Halfords 1,000 lumen light is appealing, how about an extra 600 Lumen for only £15 more? Like its slightly dimmer cousin it comes with an optional aero mount, and various rubber attachments to secure a tight grip on your bars.
The extra lumen comes with a little extra weight and bulk attached. To find out whether this Halfords bike light really turns night into day, and whether it can pass our tough durability and ease of use tests, you'll need to read our full review.
Key features: 450 lumen, doubles as a powerbank, attaches with a rubber strap, also comes with a helmet mount, 6 settings between 450 and 50 lumen, USB rechargeable
This 450 Lumen light doubles up as a powerbank that can charge other USB compatible devices, like a phone or even your rear bike lights. It can be mounted on a helmet, as well as your handlebars. It has six different light settings and Knog says it will last up to 90 hours on its Eco Flash setting.
The Knog is small and compact, but is it robust? and can a 450 Lumen light outshine lights that claim to be brighter?
Key features: 1,000 lumen, eight light settings from 15 to 1,000 lumen, attaches to the bars with a sturdy rubber strap, USB rechargeable, race mode
With 1,000 lumen to play with this Lezyne claims to pack a serious punch when it comes to illumination. It has eight different light settings between 15 and 1,000 lumen, and claims to last for 87 hours on its lowest setting. It also has a race mode, which simplifies the light down to only two settings, the brightest and economy mode.
It's small and compact and attaches easily to the bars, but does it light up the road as well as cheaper alternatives? And how does it deal with being dropped?
Key features: 600 lumen, attaches with a rubber strap, race mode, USB rechargeable, nine different light settings
This Lezyne bike light claims to last up to 44 hours on its lowest light setting. It has nine light modes in total ranging from 600 down to 15 lumen. It also has a race mode function, which is enabled if you hold the power button for five seconds. Race mode simplifies the light so that it only has two settings, the brightest one, and economy mode.
It's one of the most compact lights we tested, but is 600 lumen enough to illuminate a dark country lane?
Key features: 1,300 lumen, optional helmet mount, USB charging, remote button feature, seven light settings from 120 to 1,300 lumen, wide or focused beam
The Moon Meteor Storm has a helmet mount in addition to the handlebar mount. It's also got seven light modes ranging from 120 to a whopping 1,300 lumen when it's on full beam. This light also has an extra control button that allows you to make the lights beam wider, or narrower. The moon bike light can also be switched on and off via a button on the end of a wire that can be attached to the light and put anywhere else on the bike that might be easier for you to reach.
This light has a couple of nice additional features, like the dual beam angle, and remote button feature. But how does it compare with cheaper options, and does it pass our durability tests?
Key features: 600 lumen, daylight sensor, up to 57 hours runtime on lowest setting, seven light modes
The Moon Meter X Auto Pro light has a maximum lumen output of 600, attaches to your handlebars with a sturdy rubber strap and has seven different light modes. It also has a great auto on/off feature that responds to the light levels your riding in. This is great for extending the battery life, and also for safety as it will switch on itself if you ride through a dark tunnel, for example.
This Moon light is the cheapest front light we tested, but it has some great features like the auto light feature that switches it on and off. How does it compare with pricier competition in our tests?
Key features: 1,000 lumen, doubles as a powerbank, FlexTight grip, USB rechargeable, five light settings
The Mr Bike Light Mercury 1000 has a range of light settings up to 1,000 lumens. It attaches with a FlexTight grip that you tighten on the bars with a round dial, you can take the light on and off this attachment if you don't want to store it on the bike. This light also doubles up as a powerbank, which is a nice feature.
This light aced our waterproofing test, but how good is it at lighting up a dark road, and is it robust?
We tested seven rear bike lights ranging in price from £10 to almost £40.
All of the lights were put through a bevvy of tests including durability, visibility, battery life and more. These are the seven rear bike lights we tested:
We sent 10 front bike lights and seven rear bike lights home with one of our researchers, who is also a keen cyclist, to put them through their paces in our specially designed bike lights test.
We put each bike light through two key durability assessments. To check whether each light is waterproof, we doused them in a shower for five minutes, making sure each front bike light was subject to a steady stream of water droplets from every angle.
Good front bike lights need to be robust as well as waterproof. There's every chance you will drop yours from time to time when wrestling with the elastic strap on a cold, dark evening. To replicate this, we designed a drop test where dropped all of the front bike lights from the height of the handlebars, 10 times, onto a hard surface. Disappointingly, not all of the lights were able to pass this relatively simple test.
The brightness of a front bike light is more than just the stated lumen output on the packaging. We wanted to see how well this stated lumen output transfers to the road, and your surroundings, when you're riding. So there was nothing for it but to strap each of the lights to a bike (in turn), wait until it got dark, and head out to an unlit country lane.
After painstakingly ranking each light for how well it illuminates the road and it's surroundings, it's interesting to note that lights with higher claimed lumen output aren't always better at lighting up the way while you're riding.
For the rear bike lights we conducted a visibility test at a variety of ranges and at as much as 180 degrees (to the side) of the light, as well as directly behind.
All of the lights we tested will last at least an hour on their brightest setting. And in some cases, they'll last days on their least bright setting.
For our battery test, we wanted to do something a little different and recreate a scenario that all cyclists will have faced. The dreaded flat battery test.
We completely drained each light of all of its charge, and then gave it a quick 10-minute charge. We then timed how long the light would last on its least bright continuous setting.
Most of the lights we tested will last more than two hours from a 10-minute charge. But we tested one that we found will only give you 20 minutes of riding time from this emergency charge, and another that was just under 40 minutes - it's worth knowing which these are if you have a long journey home.
The last thing you want when you're getting ready for a bike ride is to spend ages fiddling with difficult straps or attachments for your front bike lights.
We assessed each light on how easy it is to attach to a bike while wearing thick cycling gloves, and how easy it is to remove and switch between bikes. Some lights have fiddly straps that are difficult to attach securely. The best lights are easy to attach, remove, and switch between bikes, even when you're wearing cycling gloves.
We also assessed how easy it is to turn the light on and cycle between the settings. Some lights have stiff buttons that are hard to use, or in awkward to reach places, particularly with thick gloves on. Whereas others are a joy to use, and easy to operate, even while you're riding.
We weighed each light, on the same set of digital kitchen scales.
The weights we publish are often a little higher than claimed by the manufacturer because we include the rubber or plastic strap that you use to attach the light to the bike, in our measurement. We feel this is a more accurate weight as you'll be carrying these attachments with you on the light when it isn't attached to your bike.
You can see these weights in our members only content.
For our test we chose front bike lights that cost between £30 and £60 as this is the price range the regular cyclists we consulted told us that they'd be prepared to pay.
We then picked widely available bike lights in this price range that are stocked in the major cycling retailers, such as Halfords, Wiggle, Chain Reaction Cycles and Amazon.
We ordered and paid for all of the lights we tested, just like you would. Which? doesn't accept freebies, which gives us the freedom to tell the truth about our test results.
Front bike lights broadly break down into two categories, those that allow you to be seen, and those that will allow you to see the road.