The Prototype Is Already Racing — and Already Breaking Records
The Alphafly 4 is not vaporware. It physically exists, has been raced at the elite level, and has already set a world record.
The shoe first appeared on the official World Athletics approved list under prototype code Nike-Dev 16141 just before the 2025 Chicago Marathon, making it eligible from October 2, 2025. At Chicago, American athlete Conner Mantz raced in the prototype and set a new American Record of 2:04:43. Notably, race winner Jacob Kiplimo chose to stay in the Alphafly 3 at Chicago — a telling sign that the prototype needed more validation before elite athletes fully committed to it.
The shoe was re-registered as Dev 164 on the World Athletics list as of February 2026, cleared through 12 February 2027. By March 2026, Kiplimo had made up his mind: he wore the Dev 164 at the Lisbon Half Marathon and set a new half marathon world record — the most significant performance the prototype has delivered to date.
Early retail release rumors pointed to January 2026. Those did not materialise. Current projections point to a retail launch sometime in 2026, possibly spring ahead of the fall marathon season, but Nike has confirmed nothing.
Important competition note: the Dev 164 is not approved for World Athletics Series events or the Olympics — only road races, cross country, and mountain and trail events. Lisbon qualified; the Olympic Marathon does not.
What Is Actually Changing From the Alphafly 3
The Alphafly 3 focused on smoothing out the ride with a continuous bottom unit. The Alphafly 4 appears to be taking a different approach entirely — stripping back everything that is not directly contributing to propulsion and energy return, to compete with ultra-light competitors like the Adidas Adizero Adios Pro Evo 1.
The trade-off is reduced heel cushioning. Runners who rely on the Alphafly 3's 8mm drop for Achilles protection will need to adapt.
The practical result is expected to be a more mechanical, high-energy sensation underfoot that will feel exceptional at race pace but potentially disjointed at easy effort.
The Alphafly 3's AtomKnit upper required 10–25km to break in. The 4.0 version is expected to be lighter but potentially similar in terms of needing race-pace wear-in before race day. Do not race in them cold.
Alphafly 4 vs Alphafly 3: Expected Spec Comparison
| Specification | Alphafly 3 (Current) | Alphafly 4 (Expected) |
|---|---|---|
| Price | $295 USD | TBC |
| Stack Height | 40mm | 40mm |
| Drop | 8mm | 4–6mm (expected) |
| Air Zoom Pods | Dual, continuous | Dual, independent piston |
| Upper | AtomKnit 3.0 | AtomKnit 4.0 (stripped) |
| Outsole | Full rubber coverage | Targeted zones only |
| Forefoot Rocker | Aggressive | More aggressive |
| Availability | Now — $295 | May 2026 (projected) |
| R.A.C.E. Score | 9.5/10 | TBD on release |
Who the Alphafly 4 Is Built For
The Alphafly 4 will be more demanding than the Alphafly 3 in every respect. Based on the expected geometry, this is not a shoe for casual or recreational runners.
Built for you if...
- You are a forefoot or midfoot striker with strong, consistent mechanics
- You race at sub-4:00 min/km pace where the pods and rocker engage fully
- You have raced in the Alphafly 3 and want more aggression
- Your calves and Achilles handle lower-drop shoes well
- You use race shoes exclusively for races and key sessions
- You have 3–4 race-pace sessions to break in the upper before race day
Not built for you if...
- You are a heel striker — the geometry will work against you
- You have Achilles sensitivity or a history of calf issues
- You run at conversational pace (pods require pace to engage)
- You want to use it for both training and racing
- You are new to carbon plate shoes — start with the Hoka Rocket X3
- Your target race is before May 2026 — buy the Alphafly 3 now
Should You Buy the Alphafly 3 Now or Wait?
This is the most practical question and the answer depends on your race calendar.
Buy the Alphafly 3 now if you have a target race before mid-2026. The Alphafly 3 scores 9.5/10 in our R.A.C.E. rankings, costs $295, and is one of the two best marathon shoes available in 2026. There is no performance vacuum to fill. See our full Alphafly 3 vs Vaporfly 4 comparison if you are deciding between the two current Nike options.
Wait for the Alphafly 4 if your target race is fall 2026 or later, you are comfortable with the shoe being more demanding than the 3, and you are specifically chasing maximum mechanical performance over comfort. The Alphafly 4 will likely be faster on paper — but only for runners whose mechanics can activate it properly.
One more consideration: Nike typically launches a limited Proto colorway first at a premium price point before the general release. If history repeats, the Proto drop will be limited quantity and sell out quickly. The wider general release follows a few weeks later at the standard price.
Compare the Current Top 12 Carbon Plate Shoes
While you wait for the Alphafly 4, see how the Alphafly 3 stacks up against ASICS, Adidas, Saucony and more right now.
Open the Comparison Tool →Frequently Asked Questions
When is the Nike Alphafly 4 release date?
Nike has not officially announced a release date. Early rumours pointed to January 2026 — those did not materialise. Based on prototype-to-retail timelines, industry trackers currently point to sometime in 2026, possibly spring ahead of the fall marathon season, but nothing has been confirmed by Nike. The Alphafly 4 prototype (Dev 164) is cleared for competition through February 2027, giving Nike considerable runway before a retail release is required.
What is the Nike Alphafly 4 prototype code?
The Alphafly 4 has appeared on the World Athletics approved shoe list under prototype development code Nike-Dev 16141 (also spotted as Dev 164). Under World Athletics regulations, approved prototypes can be used in professional races during a 12-month development window before retail release. Clearance on the list confirms it meets the 40mm stack height limit and other competition requirements.
How does the Nike Alphafly 4 compare to the Alphafly 3?
Based on prototype sightings and leaked specs, the Alphafly 4 is expected to be more aggressive than the Alphafly 3 in every dimension. Key expected changes include a lower drop (4–6mm vs 8mm), more independent Air Zoom pods with greater vertical travel, a stripped AtomKnit 4.0 upper to save weight, and a sharper forefoot rocker. The Alphafly 3 remains available at $295 and scores 9.5/10 in our R.A.C.E. rankings.
Is the Nike Alphafly 4 good for heel strikers?
No. Based on the expected geometry — aggressive forefoot rocker, lower drop, and isolated Air Zoom pods — the Alphafly 4 will be even less suitable for heel strikers than the Alphafly 3. It is designed specifically for forefoot and midfoot strikers at race pace. Heel strikers should see our guide to the best carbon plate shoes for heel strikers, where the Saucony Endorphin Pro 5 and Hoka Rocket X3 are the top picks.
Should I buy the Alphafly 3 now or wait for the Alphafly 4?
If you have a race before mid-2026, buy the Alphafly 3 now at $295. It scores 9.5/10 and is one of the best marathon shoes available today. If your target race is fall 2026 or later and you want maximum mechanical performance, waiting for the Alphafly 4 may be worth it — but only if your mechanics can handle a more aggressive geometry than the V3.