ocicdn

A free, global pull-through cache for the public OCI registries, built on Cloudflare Workers and R2.

Free forever. No commercial tier, ever.

usage

Each upstream registry is a subdomain. Pick the one that matches the image you want:

registry	upstream	pull through
Docker Hub	docker.io	docker.ocicdn.net
GitHub Container Registry	ghcr.io	ghcr.ocicdn.net
Quay	quay.io	quay.ocicdn.net
Kubernetes	registry.k8s.io	k8s.ocicdn.net
Google Container Registry	gcr.io	gcr.ocicdn.net
Microsoft Container Registry	mcr.microsoft.com	mcr.ocicdn.net

docker pull docker.ocicdn.net/library/alpine:3.20

Works with docker, podman, containerd, CRI-O, skopeo, buildkit, and anything that speaks the OCI distribution spec. No account, no setup.

why it's fast

6 R2 regions	WNAM, ENAM, WEUR, EEUR, APAC, OC. Routed by `cf.continent`. Africa → WEUR, South America → ENAM.
Edge cache tier	Hot blobs live in CF colos, <5 ms from the client. Under 512 MB per object — CF's limit.
Tee‑on‑miss	A single upstream pull fills client, regional R2, central R2, and edge — all in parallel.
Content‑addressed dedup	`sha256` keys. Ten customers pulling the same base layer share one byte on disk.
Herd‑lock	1000 nodes cold‑missing the same blob? One Hub fetch, 999 wait for the fill.
Planet‑scale	Cloudflare's 300+ colo anycast. Zero ops, no capacity planning.

can you trust this proxy?

Yes — because you don't have to. OCI clients verify the full content tree after every pull. If you pin by digest, your runtime guarantees byte-for-byte identity:

docker pull docker.ocicdn.net/library/alpine@sha256:77726ef6b57ddf65bb551896826ec38bc3e53f75cdde31354fbffb4f25238ebd

We physically cannot substitute content — the pull would fail its own integrity check. For additional assurance:

The proxy is byte-for-byte passthrough. We return Hub's Docker-Content-Digest header verbatim. Every response body's sha256 matches.
Source is open. Read the code that fetches from Hub and streams the bytes through: github.com/isorun/ocicdn.
Sigstore / cosign signatures pass through unchanged. cosign verify <image> works identically through us as direct from Hub.
Our upstream Hub token scope is public read-only. We can't push forged images back to Hub, ever.

limits

Pull-only. No push. No private repos.
Public images only — we don't proxy auth-gated content.