Walk a marathon.
Earn credits.
Bring a buddy — earn more.
A free, worldwide step challenge. Walk a full marathon (42.195 km) at your own pace. Solo is fine. In a group of 2–6, everyone earns +10% per extra member — if every member finishes. Fastest finisher wins 1 month of Regular membership free. No invitation needed — free sign-up, verified by email.
How it works
- Sign in (free) and join the current cohort — solo, or create/join a buddy group with an invite code.
- Walk. Log daily steps by uploading a screenshot from your phone or wearable. We convert steps → km (76cm stride).
- Hit 42.195 km. Solo finishers earn credits immediately. Group members earn once every member finishes.
- Fastest finisher of each cohort wins a free month of Regular membership.
- Each consecutive month you finish adds +5 bonus credits. Twelve in a row = 500-credit annual award (admin-reviewed).
12-month streak badges
Finish twelve cohorts in a row to unlock the annual award. Each month completed lights up a badge.
Keep going with Codex
Common questions
How much does the Codex Walking Marathon cost?
It's free to join, anywhere in the world. You only need a Codex account.
How far do I have to walk?
A full marathon: 42.195 km, tracked in daily step logs (roughly 55,000 steps). You set the pace — finish in a day, a week, or across a month.
How do buddy groups work?
Groups of 2–6 walkers share one invite code. If every member finishes the marathon, everyone earns +10% credits per extra member (up to +50% for a full group of 6).
What do I win?
25 Codex Credits (€50) for a solo finish, more with a buddy group, plus streak bonuses. The fastest finisher of each cohort wins one free month of Regular membership.
How are steps verified?
You log steps daily from your phone or wearable. Days over 40,000 steps auto-flag for admin review. Screenshot uploads and wearable snapshots are supported.
Can I do it from anywhere?
Yes — the Codex Walking Marathon is a global, remote challenge. Any country, any city, any surface.