For years, I was completely behind the trend of adopting ultra-warm down jackets, until I finally field-tested the Rab Microlight Alpine Jacket, and it completely flipped my opinion. While brands like The North Face have certainly made big, puffy coats fashionable for the city, what I truly needed for rigorous mountain adventures and multi-day trekking was a highly compressible, lightweight, and comfortable layer capable of handling serious cold-weather challenges.
My research consistently pointed me toward this specific model, and after putting it through its paces in environments ranging from the freezing tea houses of the Himalayas to the fierce winds of Patagonia, I finally understand why it has gained such legendary status among hikers, climbers, and backpackers. In this comprehensive Rab Microlight Alpine jacket review, I will break down its top strengths, technical features, and any important considerations you need to know before investing in this amazing piece of gear.
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 Microlight Alpine Jacket: Introduction
Rab’s Bestseller
There are many types of Down Jackets on the market, with the first thing to understand being the fill. Synthetic down is cheaper and not as warm, whereas natural down (i.e., feathers) is warmer but pricier. Then the scale of down called the Down Fill Power measures the loftiness of the insulation. Typically, the Down Fill ranges from 400 to 900, with higher numbers indicating better quality and insulation. The 700-fill in the Microlight offers a great balance of weight-to-warmth ratio and is affordable for a fully featured mountain down jacket.
Rab Microlight Alpine
The Rab Microlight Alpine Jacket is an all-rounder that is versatile for all-mountain activities. The Microlight Alpine is a low-profile jacket that is easy to layer or store thanks to the micro baffles used. The body and shoulders have Micro baffles for better insulation, and Nano baffles under the arm improve breathability. The Recycled 700FP Fill Down with a Nikwax Hydrophobic finish insulation combined with the DWR coated Pertex Quantum outer protects against the weather excellently. Overall, the Rab Microlight Alpine Jacket has a high warmth-to-weight ratio and packability, making it an excellent choice for outdoor enthusiasts wanting reliable performance.
Jacket Construction
- Outer: Pertex® Quantum is a soft, lightweight, windproof fabric designed for full loft and packability
- Insulation: Recycled 700FP Down with Nikwax Hydrophobic Finish
- Internally elasticated cuffs and drawcord adjustable hem for a customisable fit
- Stuff pack and high compressible design for maximum packability
- Down-filled hood for added warmth and cosiness
- 2 side zips and a chest zip for accessible storage and hand-warming lining
My Testing
I brought the Rab Microlight Alpine Jacket before travelling to Nepal to tackle the Annapurna Circuit. Now it is 4 years old and joined me on mountain adventures in the Himalayas, Alps, Canada and Patagonia. And I can safely say that it has reliably kept me warm and comfortable down to -25-degree conditions. The small stuff sack is very compressible to maximise packing space when trekking. Rab offers a range of colours to fit your taste, and I love my Beluga Blue version. This jacket has withstood the cold mountain weather thrown at it. For sustainability, the Rab Microlight Alpine Jacket uses 91% recycled content, with all the fabrics and down fill being 100% recycled, for the environmentally conscious.
Where this jacket earned its keep
I don’t review gear out of a box. Read the full destination guides where the Rab Microlight Alpine provided critical warmth from the high-altitude Himalayas to the Arctic Circle.
The hood is adjustable and is compatible with a helmet, which is ideal for climbers or Alpinists. I found it very useful in Patagonia when zip-lining across a valley. The versatility to layer the rab Microlight Alpine Jacket is what makes it such a great all-rounder. I can easily put my Arc’Teryx Proton LT Hoody underneath for extra warmth without feeling too constricted. Or if the rain starts, then I have no issues layering my Arc’teryx Beta AR Waterproof Jacket over the Rab.
The soft fleece-lined chin protector feels luxurious when hiking on the trail. And the hood has a small lip to protect your face from snow or precipitation. The lining of the Microlight has a soft texture against the skin and is very comfortable for all-day use. The Rab Microlight Alpine Jacket being reviewed is size small, and despite Rab’s Regular sizing, I feel it’s more slim fit.
Tip: Rab offers repair services which helped fix a tear and loss of filling on a Baffle
Rab Microlight Alpine Jacket:
Selling Points
Warmth
- Despite being lightweight, the 700FP Fill insulates very effectively and is a warm Down Jacket. The price means you’re getting premium insulation that is very reliable in freezing cold winter conditions. The thermal performance is maximised by using Micro-baffles on the core chest and arm areas, and then Nano baffles where breathability is required.
- Plus, with the added Nikiwax hydrophobic finish and DWR coating, it will perform better than most down jackets in the wet! The Pertex Quantum outer is designed for high windproofing, which adds to the overall warmth.
Style
- One of my favourite points is the overall look of the Rab Microlight Alpine Jacket. The fit is an alpine tapered cut, in my opinion, despite Rab saying it’s a regular fit. And the Jacket has a regular length body and arms as well. The Micro-baffles are slim compared to bigger, thicker baffles. I use the jacket for casual wearing around town or to work, as well as on mountain adventures.
Lightweight
- The warmth-to-weight ratio of the Rab Microlight Alpine Jacket is one of its strongest assets. While there are lighter and more compact jackets available, they lack warm insulation. And the heavier, bulkier jackets aren’t as suitable for backpacking, trekking or hiking due to their size and restricted movement. The Rab balances this better than the rest with the choice of 700FP insulation.
Comfort
- My favourite feature is the all-day comfort of the Rab Microlight Alpine Jacket. It has a tapered alpine fit, which gives me the confidence to wear it up mountains or around town. It has great flexibility and range of motion for basic climbing or scrambling, and will keep you toasty when stationary, such as belaying. The inner lining feels soft next to bare skin and does not stick when slightly sweaty.
Weather Resistance
- The recycled 700-fill Down has a Nikwax hydrophobic finish to help keep you dry and insulated. And combined with a Pertex Quantum outer shell and with a robust DWR treatment, this Jacket is impressive against the wet and doesn’t lose its loft even when damp. From experience, other cheaper down jackets (such as my Trespass) lose their warmth when the rain starts.
Durability
- The outer shell is made of 30D nylon Pertex Quantum ripstop, which will help with snags and tears. I have torn mine and lost some down-fill, which has made it lighter but lost some loftiness. The Rab warranty meant I could get it repaired cheaply by their experts in a few weeks.
Value
- £210 is inexpensive for a hydrophobic-down jacket that has awesome weather resistance and comfort. In comparison to the Patagonia Men’s Down Sweater™ (£280), Arc’teryx Cerium (£350) and North Face Breithorn Down Jacket (£310), the Rab Microlight Alpine Jacket is value for money. It is affordable for a brand such as Rab, given the quality of features present.
Rab Microlight Alpine Jacket:
Worth Knowing
Packability
- The 700FP Down, as mentioned, has a great balance of weight, warmth and cost; however, if packing size is a priority, then an 800FP Jacket will compress even smaller such as the Arc’teryx Cerium Hoody. This becomes important when trekking or mountaineering, and every gram counts, but it will impact your wallet for better insulation. The packed-down version (see the yellow stuff sack in the image above) is 150 x 220 mm and can mould further around other equipment in a backpack.
Wet Weather vs Synthetic
- The Rab Microlight Alpine Jacket is designed to perform well in light precipitation thanks to its innovative finishes. The hydrophobic down is better than regular down; it underperforms compared to synthetic nylon insulation over longer periods. But these synthetic jackets are less packable.
Slim Fit
- From my research, the slim fit alpine cut is not for everyone, especially people with broader shoulders. And this will also limit the layering options, so it’s best to try the jacket on before purchasing and consider buying a size up to layer well.
Internal Pockets
- One feature that would be useful is an internal zip pocket.
Best Use Cases
- Cold-Weather Trekking & Mountaineering: Whether you are pushing through the freezing, damp coastal trails in North Vancouver or facing the extreme, high-altitude elements of the Himalayas and the Andes, the Rab Microlight Alpine jacket excels. The hydrophobic down ensures that even if you get caught in a heavy mountain fog or a sudden flurry, the jacket retains its critical heat-trapping loft to protect your core.
- Alpine Climbing & Belaying: When you transition from a high-output scramble to standing completely still at a freezing belay station in the Alps, your body temperature plummets instantly. The Rab Microlight Alpine Jacket provides an immediate blast of trapped heat and features a highly articulated, climbing-helmet-compatible hood, making it the perfect layer to throw on between pitches.
- Winter Travel & Everyday Cold: Because it compresses so efficiently into its included stuff sack, it is an absolute dream for travellers navigating the winter months. It takes up minimal space in a 50L pack for a trip to Patagonia, yet the micro-baffle design looks sleek and low-profile enough to wear casually around town without making you look like a walking sleeping bag.
Kit Rankings
Competitor Showdown
While the Rab Microlight Alpine Jacket is a phenomenal all-rounder, the insulated jacket market is incredibly competitive. Depending on whether you prioritise ultralight warmth, synthetic wet-weather performance, or premium climbing features, here is how the Rab stacks up against the closest competition:
1. Patagonia Nano Puff
- The Verdict: The synthetic, wet-weather crossover alternative.
- The Details: If you frequently hike in environments that guarantee heavy, torrential downpours where even treated down might eventually wet out, the Patagonia Nano Puff is the undisputed synthetic king. Instead of goose down, it utilises 60g PrimaLoft® Gold Eco insulation. While it lacks the ultra-plush, lofty feeling of the Rab’s 700-fill down, the Nano Puff retains 98% of its warmth even when completely soaked. Weighing in at roughly 396g, it is slightly lighter than the Rab Microlight Alpine Jacket and features a sleek, brick-quilted design that crosses over beautifully from a backcountry mid-layer to a casual everyday jacket.
2. Arc’teryx Cerium Hoody
- The Verdict: The premium, high-loft ultralight hybrid.
- The Details: Arc’teryx built the Cerium for gram-counting alpinists who are willing to pay a premium. It utilises an incredibly lofty 850-fill-power down, making it noticeably warmer for its weight than the Rab Microlight Alpine Jacket. At around 337g (11.9 oz), it’s significantly lighter too. Arc’teryx also smartly places synthetic Coreloft™ insulation in moisture-prone areas (like the underarms and shoulders). The major drawback is the price tag—it is considerably more expensive than the Microlight Alpine, and the ultralight face fabric requires a bit more care around sharp rocks.
3. The North Face Summit Series Breithorn Hoodie
- The Verdict: The rugged, expedition-grade workhorse.
- The Details: Designed for serious alpine use, the Summit Breithorn steps up the warmth with 800-fill ProDown™ (which is also treated with a hydrophobic finish like Rab’s). Weighing in at 416g, it sits slightly lighter than the Rab Microlight Alpine Jacket but feels distinctly more technical. It features a Pertex® Y Fuse ripstop shell that boosts durability and water resistance. If you are pushing into higher altitudes or harsher winter mountaineering conditions, the Breithorn provides a fantastic balance of packability and rugged mountain performance.
4. Montane Anti-Freeze Hoody
- The Verdict: The closest direct competitor to the Rab Microlight Alpine Jacket.
- The Details: Montane’s Anti-Freeze Hoody targets the exact same hiker as the Microlight Alpine. It features a similar 100% recycled Pertex® Quantum Eco outer and is stuffed with 750-fill water-resistant HyperDRY™ down. It weighs around 420g, making it just a fraction lighter than the Rab Microlight Alpine Jacket. The fit is slightly different (often feeling a bit roomier in the shoulders), but in terms of warmth, eco-credentials, and price point, it is a brilliant alternative if the Rab’s fit doesn’t quite work for your body shape.
Final Thoughts
The Rab Microlight Alpine Down Jacket absolutely excels at providing lightweight warmth and premium comfort for serious outdoor enthusiasts. While it is not designed to act as a waterproof hardshell in prolonged, torrential wet conditions, its stellar performance in cold and dry alpine settings makes it an incredibly reliable choice for mountain adventures and beyond.
The Rab Microlight Alpine Jacket offers fantastic weather protection thanks to its hydrophobic down, alongside a brilliant warmth-to-weight ratio and unbeatable comfort at a very attractive price tag. These features make it highly versatile for virtually all types of outdoor pursuits. Whether you are pushing up a freezing trail in the Alps or just wearing it casually around town in North Vancouver, it truly is an affordable, premium all-rounder that will not let you down.
What down jacket would you recommend trying next? Please share this post with fellow outdoor lovers who are looking for a warm, durable puffer, and stay tuned to Backpacker’s Mentality for more in-depth kit reviews coming up!
FAQs
Is the Rab Microlight Alpine jacket waterproof?
No, it is not fully waterproof. However, it is highly weather-resistant. The 30D Pertex® Quantum outer shell is treated with a fluorocarbon-free DWR (Durable Water Repellent) finish that easily sheds light snow and brief drizzles. Additionally, the 700-fill down is treated with a Nikwax hydrophobic finish, meaning it absorbs significantly less water, dries faster, and retains its loft even if you get caught in a damp fog. For heavy rain, you still need a dedicated hardshell over the top.
How warm is the Rab Microlight Alpine?
Rab does not provide official temperature ratings due to individual variables, but the Microlight Alpine is considered the perfect mid-weight “three-season” puffer. Moving fast on a high-altitude climb, it provides incredible warmth in sub-zero temperatures. For static use—like sitting around a backcountry campsite in the evening—it is perfectly comfortable down to around freezing (32°F / 0°C) with a good base layer.
Does the Rab Microlight Alpine pack into its own pocket?
No, unlike some ultralight competitors, it does not pack into its own pocket. Instead, Rab includes a separate lightweight stuff sack. When compressed into the sack, it shrinks down to roughly the size of a small loaf of bread, making it easy to stash in a trekking pack.
How does the sizing run on the Rab Microlight Alpine?
Historically, Rab had a very slim, European alpine fit. However, recent models of the Microlight Alpine have been updated to a “Regular” fit. This provides just enough room across the chest and shoulders to comfortably wear a heavy fleece or mid-layer underneath without restricting your mobility during technical scrambles.
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