The Rab Infinity Alpine Jacket is built for the kind of cold where a standard lightweight down jacket simply is not enough. Rab is widely recognised as one of the strongest brands for premium down insulation, and when my partner needed a reliable, ultra-warm jacket before our winter trip to Iceland, the Infinity Alpine immediately stood out as the serious option.
I personally use the Rab Microlight Alpine for fast-moving local hikes and everyday mountain layering, but it is not designed for deep-winter conditions, biting wind or proper alpine cold. That is where the Rab Infinity Alpine vs Microlight comparison becomes important. The Microlight is a versatile lightweight down jacket, while the Infinity Alpine is a much warmer, more technical piece built for harsh environments.
In this Women’s Rab Infinity Alpine Jacket review, I’ll break down why this jacket works so well for freezing temperatures, winter travel and alpine conditions. With 800-fill European goose down, zoned Rab GORE-TEX Infinium jacket Windstopper fabric and mountaineering-focused features, it has the warmth and weather resistance needed for serious cold.
This guide covers the key specs, strengths, weaknesses, ideal use cases, kit rating and whether it deserves consideration as one of the best women’s mountaineering down jacket options for winter adventures.
Field Note: This guide contains affiliate links. If you purchase gear through these links, I may earn a small commission at no extra cost to you. I only recommend equipment I have personally mountain-tested and trust.
Rab Infinity Alpine Jacket: Introduction
Rab Infinity Alpine Jacket: Overview
The Rab Infinity Alpine Women’s Jacket is a windproof down jacket that is exceptionally lightweight for this level of warmth and protection. With a close, regular fit, the Rab Infinity Alpine Jacket excels on alpine-style, high-energy ascents in tough winter conditions. It’s built with two weights of windproof GORE-TEX INFINIUM™ WINDSTOPPER® technology: ultralight around the body to keep weight and bulk down, and heavier weight around the shoulders, upper body, and outer arms, for durability in rugged environments. Filled with 800FP down and designed to maximise mobility, it’s ideal for upward progress in wild winter weather. The sizing for the Rab Infinity Alpine Jacket is true, with my girlfriend (5ft 1″) opting for a Small for layering space.
Rab Infinity Alpine Jacket
- Weight 494g / 17.4oz — Size S / UK 10
- Outer Material Zoned GORE-TEX INFINIUM™ Windstopper® — 30D & 15D
- Inner Material 20D recycled nylon lining — 38g/m²
- Insulation 800FP European goose down
- Fit Regular fit
- Best For Winter travel, alpine conditions, mountaineering layering and sub-zero temperatures
- Price £365 / $450
Rab Infinity Alpine Jacket: Key Features
- 2 YKK® zipped hand pockets, 1 YKK® zipped internal chest pocket for added storage
- Highly compressible for stashing in a pack with a stuff sack included
- Minimally seamed overlay panel across upper body, shoulders and upper sleeve for added weather protection and reinforced fabrics for rugged terrain.
- Move freely with a refined fit and arm articulation.
- Harness-friendly two-way front zip with 2‑way YKK® Vislon front zip
- Zoned GORE-TEX INFINIUM™ WINDSTOPPER® fabrics: 30D (64gsm) & 13D (45gsm)., Lining 20D recycled nylon (38 g/m²)
- Helmet-compatible hood seals out high winds.
- 800FP European goose down with Nikwax fluorocarbon-free hydrophobic finish (162g/ 5.7oz, Size 10).
- Optimised glove-fit with elasticated, adjustable cuffs.
- Minimises water ingress with inter-stitch baffle technology.
Rab Infinity Alpine Jacket: Strengths
- Exceptional Warmth-to-weight Ratio – The combination of 800 FP hydrophobic down (~162 g) and ultralight shell gives impressive warmth for less than 500 g – ideal for alpine ascents where weight matters. Plus, the use of Advanced stitch-through with “switch-back” overlapped baffles minimises cold spots.
- Weather Protection – GORE‑TEX INFINIUM WINDSTOPPER® is fully windproof and water-resistant, and the fill-down is treated with Nikwax hydrophobic treatment (RDS certified) to resist dampness and keep warmth in during light precipitation.
- Technical Design – Helmet-compatible hood with stiffened peak, articulated arms, and harness-friendly 2‑way zip make it mountaineering-ready and more suitable for climbing.
- Packability – The Rab Infinity Alpine Jacket uses highly compressible down and a lightweight shell that allow packing into small backpack pockets—convenient for multi-day ventures
- Ethical and Sustainable Materials – RDS-certified down, fluorocarbon-free finish, and recycled lining materials align with sustainable practices
- Durability– Designed for mountaineering and climbing use, the Infinity Alpine uses a zoned Shell Fabric Zoned with GORE‑TEX INFINIUM™ WINDSTOPPER® technology. The combination of 30D & 13D patches means it adds robustness where needed and is lighter in other places.
Rab Infinity Alpine Jacket: Considerations
- Limited Wet-weather Performance – Despite being water-resistant, the Rab Infinity Alpine Jacket is not fully waterproof. The untreated seams eventually wet out under heavy rain. Best used as a belay jacket, not for continuous snow or soaked conditions.
- Sizing quirks– The regular fit is close-fitting, and for layering, it could be worth sizing up given it’s designed for cold weather use.
- Cuff Design – A small feature on the Rab Infinity Alpine Jacket is that the elasticated cuffs are not as effective as Velcro or thumb loops in preventing wind or snow from sneaking inside the sleeve.
- Price – There are cheaper synthetic down jackets available for a lot less, but for the quality down that Rab is known for, the price is a premium. Additionally, the 800FP adds to this, rather than the 700FP found in the Microlight jackets. It’s an investment; however, discounts can be found.
Rab Infinity Alpine Jacket: Best Cases
This is not a jacket for a brisk autumn walk in the park; it is a specialised tool built to conquer serious winter environments. Here is exactly where the Women’s Rab Infinity Alpine truly shines—and where it reaches its limits:
Where it Shines:
- Fast, Alpine-Style Ascents & Mountaineering: Thanks to its phenomenal warmth-to-weight ratio and high water resistance, it is perfect for fast-moving ascents. When tackling demanding, high-altitude routes—like the freezing, oxygen-deprived trails of Peru and Bolivia—it provides elite thermal protection without weighing down your pack.
- Exposed, Snowy Environments: If you are navigating an exposed ridge or a snowy glacier, the GORE-TEX INFINIUM™ Windstopper® technology is a game-changer. It ensures that brutal mountain wind chill won’t strip away your trapped body heat, keeping your core completely protected from the elements.
- Cold-Climate Backpacking & Travel: For backpackers exploring notoriously cold climates like Scandinavia, Iceland, or the deep Canadian winter, this is the perfect insulation layer. It compresses down beautifully for late-summer or autumn road trips heading far up north into the Yukon, providing instant, luxurious warmth around a frosty campsite.
Where this jacket earned its keep
I don’t review winter gear from a hanger. These are the destination guides where the Rab Infinity Alpine Jacket proved itself in cold weather, biting wind and winter travel conditions.
Where to Reconsider (The Limitations):
Casual City Use: Because it is packed with 800-fill down and designed for the mountains, it has a bulkier, highly technical aesthetic. It is much less casual in style than the everyday Rab Microlight Alpine.
Heavy, Wet Weather: While highly weather-resistant, it is not a raincoat. If the weather turns genuinely wet, you absolutely must throw a dedicated waterproof hardshell over the top so you do not compromise the down jacket’s effectiveness.
Severe, Static Belaying: Depending on your base and mid-layers, if the temperature drops to extreme sub-freezing levels and you are standing completely still for hours (like a long, severe winter belay), this jacket might not be enough. In those highly static situations, a heavier, max-loft jacket like the Rab Neutrino Pro is the safer choice.
Rab Infinity Alpine Jacket: Alternatives
While the Women’s Rab Infinity Alpine is an absolute fortress against the cold, the technical down market has several incredible options depending on your specific needs for weight, weather resistance, or budget. Here is how it stacks up against the closest competition:
- 1. Rab Infinity Microlight Down Jacket – The streamlined, fast-and-light sibling.
- The Details: If you love the concept of the Infinity Alpine but find it slightly too bulky for your specific style of hiking, the Infinity Microlight is the perfect compromise. It uses the exact same highly protective GORE-TEX INFINIUM™ WINDSTOPPER® shell, but utilises a slightly lighter fabric and a slimmer, more tailored cut. It is the ideal choice for alpinists who prioritise saving weight and maximising packability without sacrificing that crucial windproof barrier.
- 2. Rab Microlight Alpine Jacket – The versatile, eco-conscious everyday classic.
- The Details: This is the women’s version of the jacket I personally use and rely on. While it drops the GORE-TEX shell in favour of standard Pertex® Quantum, it is a brilliant mid-weight option for moderate climates. It features 100% recycled materials and smartly mapped micro-baffles that look slightly more casual for city use while still retaining serious technical chops for the trail. (Check out my full, in-depth review of the Men’s Microlight Alpine here for more details!)
- 3. Rab Neutrino Pro Down Jacket – The ultimate high-altitude, extreme-cold bunker.
- The Details: If you are heading into dangerously cold environments where you will be entirely static—like sitting at a freezing belay station or resting at an exposed high-altitude basecamp—the Neutrino Pro is arguably the best technical mountaineering jacket on the market. It is noticeably warmer and heavier than the Infinity Alpine, packed with a massive amount of 800-fill down. It prioritises absolute maximum thermal protection and top-tier comfort over fast-and-light mobility.
- 4. Patagonia Down Sweater™ Hoody – The ethical, versatile 4-season crossover.
- The Details: Patagonia’s flagship down jacket is a legendary piece of gear for a reason. It offers incredibly lightweight, windproof warmth utilising 800-fill power down at a very similar price point to the Rab. What sets it apart is its exceptional versatility and sustainability—it is crafted from NetPlus® 100% post-consumer recycled nylon (made from recycled fishing nets) and uses strictly ethically sourced down. It is slightly less rigid and technical than the Infinity Alpine, making it perfect for both the backcountry and everyday winter wear.
- 5. Arc’teryx Cerium Jacket / Hoody – The premium, ultra-lofty backcountry specialist.
- The Details: Sitting at the upper end of the price spectrum, the Cerium is engineered for gram-counting minimalists who demand the absolute best. It utilises an ultra-premium 850-fill power down, meaning it achieves an unparalleled warmth-to-weight ratio. Arc’teryx also strategically maps synthetic Coreloft™ insulation in moisture-prone areas (like the shoulders and underarms) to prevent wetting out. It is lighter, incredibly stylish, and more suited to punishing, rugged climates than the Patagonia, serving as a direct, high-end competitor to the Neutrino Pro.
Rab Infinity Alpine Jacket: Kit Ratings
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Rab Infinity Alpine Jacket: Final Thoughts
The Women’s Rab Infinity Alpine Down Jacket is an absolute standout performer when technical warmth, packable lightness, and alpine-ready features are your core priorities. Its elite 800-fill thermal performance, combined with the incredibly thoughtful GORE-TEX Infinium weather resistance and mountaineering-focused details, makes it a top-tier choice for anyone serious about winter ascents or navigating freezing environments.
While it is important to remember that it doesn’t replace a dedicated waterproof hardshell in heavy rain, and its premium price point may deter casual city users, it is undeniably one of the best women’s down jackets on the market today. In our opinion, if you are heading into extreme cold, it is a piece of safety equipment completely worthy of the investment.
What is your favourite down jacket for sub-zero temperatures? Please comment below, share this post with anyone looking to upgrade their winter layering system, and stay tuned for more in-depth kit reviews!
FAQs
Is the Rab Infinity Alpine Jacket waterproof?
No, it is not fully waterproof, but it is highly weather-resistant. The outer shell is built with zoned GORE-TEX INFINIUM™ WINDSTOPPER® fabric, which completely blocks freezing winds and easily sheds dry snow or light, icy drizzle. Additionally, the 800-fill down is treated with a Nikwax hydrophobic finish. However, in heavy, prolonged rain, the seams will eventually wet out, so you will still need a hardshell for true downpours.
How does the Rab Infinity Alpine compare to the Microlight Alpine?
The Microlight Alpine is a fantastic, versatile mid-weight jacket for everyday use and moderate 3-season hiking. The Infinity Alpine, however, is a massive step up in technical performance. It utilises premium 800-fill goose down (compared to the Microlight’s 700-fill) and features a much more robust, windproof GORE-TEX shell. It is built specifically for extreme cold, technical mountaineering, and high-altitude belaying.
Does the Rab Infinity Alpine have a helmet-compatible hood?
Yes. Because it is designed for technical alpine climbing and mountaineering, the down-filled hood is fully adjustable and easily fits over a standard climbing helmet. It also features a stiffened peak to keep driving snow out of your eyes.
What is the fit like on the Women’s Rab Infinity Alpine?
It features Rab’s “Regular Fit.” Because it is designed as a deep-winter outer layer, it is cut slightly roomier in the shoulders and torso than their slimmer, casual jackets. This allows you to comfortably wear a heavy fleece or base layers underneath without restricting your arm movement when reaching for climbing holds or using trekking poles.
