In short: For cutting metal in 2026, a fiber laser is the default choice: it uses far less electricity, cuts thin and medium sheet faster, handles reflective metals such as copper and brass, and needs less maintenance. CO₂ lasers still make sense for non-metals such as wood and acrylic, and some users prefer their edge finish on thicker plate. Most comparisons online were written when fiber lasers had 3–6 kW; with today's 12–40 kW fiber sources, compare production speed and cost per part at your own thicknesses.
Why most comparisons you find are out of date
Much of what ranks for "fiber vs CO₂" was written when fiber cutting machines were new. One widely cited article from 2013, written by a laser machine manufacturer, compares fiber machines of 2–4 kW with CO₂ machines of up to 6 kW (source 3). A 2020 comparison by another manufacturer uses 4 kW as its reference (source 2). Both are useful for the physics, but fiber laser power for sheet-metal cutting has moved far beyond that — our own HL-F series runs at 20–40 kW. Read the numbers below with their date in mind.
The core difference: wavelength
A fiber laser emits at about 1.07 µm (source 2); a CO₂ laser emits in a band centred near 10.6 µm (source 1) — roughly ten times longer. Metals absorb the shorter fiber wavelength more readily, which is why fiber lasers cut thin sheet so quickly and can process reflective metals such as copper and brass, which are a risk for CO₂ optics (source 3). Many non-metals such as wood and acrylic absorb the CO₂ wavelength well, which is why CO₂ remains common for those materials (source 5).
The wavelength also changes the beam delivery: fiber light travels through a flexible fiber cable to the cutting head, while a CO₂ beam is guided by mirrors through the machine.
Electricity: the biggest running-cost difference
A manufacturer that sells both technologies states that a 4 kW fiber laser including its chiller draws about 18 kW at full power, against about 70 kW for a CO₂ laser of the same power with its chiller (source 2). The 2013 article reports a 3 kW fiber machine using about one third of the electricity of a 4 kW CO₂ machine on average, and one customer's electrical load falling from 37 kW to 16 kW after switching (source 3). Current industrial fiber lasers are quoted at over 30 % wall-plug efficiency (source 4). For a machine running two shifts, that difference is a large part of the cost per hour — put your own tariff into the cost per part calculator.
Speed: thin sheet, thick plate and piercing
- Thin sheet: in the 2013 comparison, a fiber machine cut 1 mm mild, galvanised or stainless steel about three times faster than a 4 kW CO₂ machine, and about twice as fast at 2 mm (source 3). The 2020 comparison reports up to three times the speed on thin aluminium (source 2).
- Thicker plate at equal low power: the 2013 article found CO₂ faster above roughly 5 mm and faster at piercing (source 3); the 2020 article reports similar speeds on mild steel with oxygen but much shorter fiber pierce times (source 2).
- Today: those comparisons were made at 3–4 kW. A 20–40 kW fiber laser is a different machine on thick plate; compare measured production speeds at your main thicknesses — see our fiber laser cutting thickness chart.
Edge quality
The 2020 manufacturer comparison states that CO₂ produces a finer edge in all thicknesses, with the difference growing as material gets thicker — for mild steel above about 12.7 mm (0.5 inch) in particular (source 2). If edge finish on thick plate is critical for your parts, ask for test cuts on both technologies; with fiber, nozzle, gas and focus settings make a large difference. Send your part through our test cut request.
Maintenance and safety
A fiber laser source has no mirrors or moving parts in the beam generation; one manufacturer claimed around 50 % longer service intervals and lower servicing cost than CO₂ (source 3 — a manufacturer's claim). CO₂ systems need beam-path mirrors kept clean and aligned, and laser gas.
Safety works differently. The fiber wavelength passes through ordinary clear plastics and is particularly hazardous to the eyes, so fiber cutting machines are fully enclosed and their viewing windows need filters rated for that wavelength (source 2). Always check that a machine's enclosure and windows are specified for the fiber wavelength.
Replacing a CO₂ machine: what changes in the shop
- Electrical supply: a fiber machine of the same power usually needs a smaller connection — but if you move to a much higher power at the same time, recalculate the supply (see fiber laser power requirements).
- Gas: no laser gas is needed for the fiber source itself; assist gas for cutting is still required, and high-power fiber machines can often cut thin and medium sheet with compressed air (see nitrogen vs oxygen laser cutting).
- Programs and parameters: nesting files carry over, but cutting parameters are different for each technology — plan time for parameter tuning on your common materials.
- Operators: daily care shifts from mirror cleaning to cutting-head optics, nozzles and protective windows.
Side-by-side comparison
| Fiber laser | CO₂ laser | Source / note | |
|---|---|---|---|
| Wavelength | ≈ 1.07 µm | ≈ 10.6 µm | Sources 1, 2 |
| Electrical draw incl. chiller, 4 kW source | ≈ 18 kW | ≈ 70 kW | Source 2 (manufacturer, 2020) |
| Thin sheet (1–2 mm) | 2–3× faster than 4 kW CO₂ | Slower | Source 3 (2013, 3–4 kW) |
| Thick plate at equal low power | Similar or slower; faster piercing | Competitive | Sources 2, 3 — re-check at high power |
| Reflective metals (copper, brass) | Yes | Risk to optics | Source 3 |
| Non-metals (wood, acrylic) | Not suited | Common use | Source 5 |
| Edge finish, thicker plate | Good; depends on setup | Finer according to one manufacturer | Source 2 |
| Beam delivery | Fiber cable | Mirrors | |
| Maintenance | Lower (no beam-path mirrors in source) | Mirrors, laser gas | Source 3 (manufacturer claim) |
| Available power today | Up to tens of kW for sheet-metal cutting | Typically lower for this use | Compare at your thickness |
How to decide
- If you cut metal only — especially thin and medium sheet, stainless, aluminium, copper or brass — choose fiber.
- If non-metals are a large share of your work, CO₂ (or a separate non-metal machine) is the better fit.
- If you cut mostly thick plate and edge finish is critical, compare test cuts from a high-power fiber laser against your current CO₂ edges.
- If you own a working CO₂ machine, calculate the electricity and maintenance saving per year before replacing it — it often decides the timing.
Frequently asked questions
Is fiber laser better than CO2 for cutting metal?
For most metal cutting, yes: fiber lasers use much less electricity, cut thin and medium sheet faster, handle reflective metals such as copper and brass, and need less maintenance. CO2 remains relevant for non-metals and, according to one manufacturer, gives a finer edge on thicker plate.
How much electricity does a fiber laser save compared with CO2?
One manufacturer that sells both states that a 4 kW fiber laser with chiller draws about 18 kW at full power, against about 70 kW for a CO2 laser of the same power. Your saving depends on power level, hours and tariff.
Can a CO2 laser cut copper or brass?
Reflective metals such as copper and brass are a risk for CO2 laser optics; fiber lasers are the usual choice for them.
Why do some shops still use CO2 lasers?
Because they cut non-metals such as wood and acrylic well, because existing machines are paid off, and because some users prefer the CO2 edge finish on thicker plate.
What wavelength does a fiber laser use compared with CO2?
A fiber laser emits at about 1.07 µm; a CO2 laser at about 10.6 µm, roughly ten times longer.
Sources
- IUPAC Gold Book, “carbon dioxide laser (CO2 laser)” — emission band centred near 10.6 µm — old.goldbook.iupac.org (accessed 2026-10-25)
- Messer Cutting Systems, “Fiber laser vs CO2 laser – which technology is right for your application?” (manufacturer, 22 Dec 2020) — 1.07 µm, power draw incl. chiller, speed, edge quality, safety — in.messer-cutting.com (accessed 2026-10-25)
- Laser Focus World, “Fiber versus CO2 laser cutting” (written by a laser machine manufacturer’s UK managing director, 13 Nov 2013) — speed, electricity, maintenance, reflective metals — laserfocusworld.com (accessed 2026-10-25)
- Laser Focus World, “High-efficiency optical pumping” — industrial ytterbium fiber lasers above 30 % wall-plug efficiency — www.laserfocusworld.com (accessed 2026-10-25)
- Thunder Laser, “CO2 vs. Fiber” (manufacturer) — CO2 for wood, acrylic and other non-metals — old.thunderlaser.com (accessed 2026-10-25)