CO₂, Er:YAG, or Fraxel? The Resurfacing Decision Is Mostly About Depth, Downtime, and Risk

“Laser resurfacing” sounds like one procedure until you try to schedule your life around it.

Fractional CO₂, Er:YAG and nonablative fractional lasers can all be used to improve texture, scars and signs of photodamage, but they create different levels and patterns of tissue injury. That difference is the treatment.

The practical decision is not which laser has the best reputation. It is how much correction you are trying to create, how much recovery and pigment risk you can reasonably accept, and whether the provider can match the device and settings to your skin.

First distinction: ablative versus nonablative

Ablative lasers remove or vaporize portions of the skin surface while creating controlled thermal injury. CO₂ and Er:YAG are the major resurfacing names in this category. Fractional versions treat columns of skin while leaving intervening tissue untreated, which generally shortens recovery compared with older fully ablative approaches.

Nonablative fractional lasers create controlled dermal injury while preserving more of the epidermal surface. Fraxel is a brand name associated with several fractional platforms; in consumer language it is often used as shorthand for nonablative fractional resurfacing, although the exact device matters.

In broad terms, more aggressive tissue injury can create more dramatic improvement—and also more redness, swelling, crusting, infection risk, pigment change and downtime. That is not a flaw in the technology. It is the bargain.

Fractional CO₂: the bigger intervention

CO₂ lasers operate at 10,600 nm and interact strongly with water in tissue. Fractional CO₂ resurfacing can produce meaningful improvement in atrophic acne scars and other texture concerns, but the treatment carries a larger recovery burden than many nonablative options.

Recent systematic reviews continue to place fractional CO₂ among the more effective laser options for atrophic acne scarring, while also emphasizing heterogeneity in protocols and outcomes. A 2025 meta-analysis comparing ablative and nonablative laser treatment for acne scarring found a trade-off between efficacy and adverse-effect/downtime considerations rather than one universally superior choice.

If someone wants substantial scar or texture correction and can accept the recovery, CO₂ may deserve discussion. If the event calendar, skin-tone risk or tolerance for visible healing makes that burden unacceptable, “stronger” may not mean better.

Er:YAG: ablative, but with a different thermal profile

Er:YAG operates at 2,940 nm and is also strongly absorbed by water. It generally creates less residual thermal injury than CO₂ at comparable ablative depths, which can mean a different healing and risk profile.

A 2024 systematic review and meta-analysis comparing fractional CO₂ with fractional Er:YAG for atrophic acne scars found both effective, with differences in efficacy and adverse effects that should be interpreted in the context of study variability. The practical point is not that Er:YAG is “CO₂ lite.” It is another ablative resurfacing tool with its own depth, thermal behavior and treatment logic.

Ask what problem the provider believes Er:YAG solves better in your case and what result would justify choosing it over CO₂ or a nonablative series.

Fraxel and other nonablative fractional lasers: less disruption, usually more patience

Nonablative fractional lasers such as 1550-nm erbium-glass systems create microscopic zones of thermal injury without vaporizing the entire surface. Recovery is commonly shorter than with ablative resurfacing, but multiple sessions may be needed to accumulate the desired improvement.

The AAD notes that nonablative laser treatment often requires a series. “Minimal downtime” can hide a different kind of burden: more appointments, more cumulative cost, repeated sun restrictions and months of incremental change.

That may be exactly the right trade for someone who cannot disappear from work or social life for a more visible recovery. The calendar is part of efficacy because a treatment you cannot realistically complete is not an elegant plan.

Acne scars make the comparison more complicated

Atrophic acne scars are not one shape. Ice-pick, rolling and boxcar scars can require different strategies. The American Academy of Dermatology specifically notes that acne-scar treatment is individualized and commonly multimodal.

A laser can improve surface texture and collagen remodeling, but a tethered rolling scar may need subcision before resurfacing has much chance to change the contour. Deep ice-pick scars may require focal techniques. Active acne should generally be controlled so that the treatment plan is not polishing old scars while new ones are forming.

This is why asking “Which laser is best for acne scars?” is one question too early. Ask what kinds of scars you actually have.

Skin tone can change which level of injury makes sense

Darker skin is more prone to post-inflammatory hyperpigmentation after laser treatment. That does not prohibit ablative or fractional resurfacing, but it raises the importance of device selection, conservative parameters, pretreatment planning where appropriate, sun avoidance and operator experience.

A provider should be able to show experience with your skin tone and concern, explain pigment-risk mitigation, and discuss whether a less aggressive series might produce a better risk-adjusted result than one dramatic session.

The downtime comparison needs more than a number

Ask what recovery actually looks like:

• How long is the skin raw, crusted or actively peeling?
• How long does conspicuous redness typically persist?
• When can you use ordinary skincare and makeup again?
• When can you exercise, swim, use saunas or return to high sun exposure?
• What infection or cold-sore precautions apply?
• How long can pigment changes continue after the visible peeling ends?

“Five days of downtime” can mean five days before work and several more weeks before the skin looks fully settled in every lighting condition. Ask for both.

One aggressive session versus a series is partly a financial decision

Ablative resurfacing may carry a higher single-treatment burden. Nonablative fractional treatment may require multiple sessions. The only honest price comparison includes the complete expected course, medications and aftercare, time away from work or events, travel and maintenance.

Use The Maintenance Math rather than comparing promotional session prices.

The consultation should produce a reason, not a brand preference

• What exact laser and wavelength are you proposing?
• Is it ablative or nonablative, and how fractional is the treatment?
• What specific texture or scar pattern are you targeting?
• Why this technology rather than CO₂, Er:YAG, nonablative fractional treatment, microneedling or another option?
• What improvement range is realistic after the complete course?
• What recovery should I expect beyond the first visibly rough days?
• How does my skin tone change your settings and pigment-risk plan?
• What combination treatment might be needed if the scar is tethered or deep?

For the individual treatment decisions, continue to fractional CO₂ resurfacing or Fraxel and nonablative fractional lasers. If the reason for resurfacing is acne scarring, use the acne-scar treatment map first; if pigment risk is central, read Laser Treatments in Darker Skin.

The Verdict

CO₂, Er:YAG and Fraxel-style nonablative fractional resurfacing are not three versions of the same facial. They are different ways of spending tissue injury to buy remodeling.

The right choice is not automatically the treatment with the most dramatic before-and-after photograph. It is the treatment whose expected improvement is worth its recovery, risk, cost and number of sessions for the skin actually being treated.

This article is educational and does not determine which resurfacing procedure is appropriate for a particular person.