Rollback and gradual rollouts

Rollback

From Deployments or Versions, Roll back on any earlier version sends 100% of production traffic to it. The confirmation takes an optional reason, which Cloudflare records with the deployment. It runs wrangler rollback with the project’s account and environment.

A rollback raises a notification and goes into the project’s History.

Gradual rollouts

Split traffic sends a percentage of production traffic to another version, through wrangler versions deploy a@90% b@10%.

• Pick the two versions and the split. 0% is allowed, to keep a version deployed with no traffic.
• The confirmation has a box you have to tick.
• To finish, split again at 100% / 0%, or roll back.

Cloudflare’s Deployments list shows the split, with its message.

Verified

Rollback and a 90/10 split and back were run on a real Worker on 2026-10-14. See What’s proven.