Last updated September 2026 · By Christopher Smith, Bright Light LED
Short answer: choose a flashlight by the job first, then check five specs: lumens for total brightness, candela and beam distance for reach, runtime at the mode you will use, water rating, and battery type. For most people, a USB-C rechargeable light with 300 to 1,000 lumens, a good low mode and at least an IPX6 rating is the right place to start.
Start with the job
| If you need a light for… | Look for | Shop |
|---|---|---|
| Everyday carry | Small, 300–2,000 lumens, USB-C, pocket clip | Everyday carry |
| Keys and backup | Tiny, waterproof, 20–300 lumens | Keychain lights |
| Duty and security | Tail switch, high candela, tough body | Duty & professional |
| Hunting and long range | High candela, long beam distance | Hunting & long-range |
| Camping and hands-free work | Headlamp with red mode, or a lantern | Headlamps |
| Mechanics and job sites | Magnetic base, wide flood beam | Work lights |
| Emergency kit | AA batteries, long storage life | BW1 AA flashlight |
1. Lumens: total brightness
Lumens measure all the light a flashlight puts out. More lumens light up more area, but the number says nothing about how far the beam reaches or how long the light holds that output. Most people need 300 to 800 lumens day to day. Our lumens guide breaks it down by task.
2. Candela and beam distance: reach
Candela measures the intensity at the brightest point of the beam. Beam distance, under the ANSI FL1 standard, is how far the light travels before it drops to 0.25 lux, about the brightness of a full moon. The two are linked: double the beam distance takes four times the candela. If you need to see or identify something far away, compare candela, not lumens.
3. Beam type: flood, throw or zoom
A flood beam spreads light wide for close work and walking. A throw beam concentrates it for distance. A zoom head, like the one on the BW1, lets you switch between the two. Some lights, such as multi-source flat EDC lights and three-source headlamps, give you separate spot and flood emitters.
4. Runtime: how long it lasts
Under ANSI FL1, runtime is measured until output falls to 10% of its starting level, so a light can dim well before the official runtime ends. Almost every high-output light steps down from turbo after a few seconds or minutes to control heat. Look at the runtime for the mode you will actually use, and value a good low mode.
5. Water resistance: IP ratings
- IPX4: splashes from any direction
- IPX6: powerful water jets and heavy rain
- IPX7: submersion to 1 meter for 30 minutes
- IPX8: submersion beyond 1 meter, to a depth the manufacturer specifies
The first digit covers dust; an X means it was not tested for dust. For boating, fishing or anything near water, choose IPX7 or IPX8.
6. Battery type
- Built-in rechargeable: slim and convenient, but you cannot swap in a spare.
- Removable lithium-ion (18650, 21700): high performance and swappable. See our battery size guide.
- AA or AAA: lower performance, but available everywhere and ideal for emergency kits.
7. Charging
USB-C built into the light means one cable for your phone and flashlight. Magnetic charging is quick to connect and helps water resistance, but you need the specific cable. Lights with removable cells can also use an external battery charger, which lets you charge spares.
8. Switches and interface
A tail switch gives instant momentary light and is preferred for tactical and duty use. A side switch is easier for cycling modes one-handed. Look for a lockout so the light does not turn on in a pocket or bag, and a simple interface you can use without looking.
9. Size, build and extras
Aluminum bodies with hard anodizing are the standard for durability. An impact rating tells you the drop height a light survived in testing. Useful extras include a magnetic tail for hands-free work, a battery indicator, a red mode for night vision, and UV for inspection.
Frequently asked questions
What is the most important spec on a flashlight?
It depends on the job. For close work, lumens and beam width matter most. For seeing far, candela and beam distance. For long use, runtime at a sustainable output.
Is a higher lumen flashlight always better?
No. Very high output drains batteries quickly, creates heat, and can wash out your vision at close range. A light with a good range of modes is more useful than one with the highest peak.
Rechargeable or battery flashlight?
Rechargeable for regular use because it is cheaper to run and more powerful. Keep an AA or AAA light as a backup for emergencies.
What does ANSI FL1 mean on a flashlight?
It is a standard for measuring lumens, candela, beam distance, runtime, water resistance and impact resistance, so specs from different brands can be compared fairly.
Keep reading
See the best EDC flashlights under $100, compare flat EDC flashlights, or browse every light we stock.
