Source: https://seerepo.com/compare/flannel-io/flannel/vs/k3s-io/k3s
Markdown source: https://seerepo.com/compare/flannel-io/flannel/vs/k3s-io/k3s.md
Description: flannel and k3s share 5 technologies: net/http, etcd, k8s.io/klog/v2, github.com/Microsoft/hcsshim, and github.com/coreos/go-systemd/v22. Both are written in Go.

# flannel vs k3s

flannel and k3s share 5 technologies: net/http, etcd, k8s.io/klog/v2, github.com/Microsoft/hcsshim, and github.com/coreos/go-systemd/v22. Both are written in Go.

- [flannel-io/flannel](https://seerepo.com/r/flannel-io/flannel): flannel is a network fabric for containers, designed for Kubernetes
- [k3s-io/k3s](https://seerepo.com/r/k3s-io/k3s): Lightweight Kubernetes

## What they share and what sets them apart

- In common: net/http, etcd, k8s.io/klog/v2, github.com/Microsoft/hcsshim, github.com/coreos/go-systemd/v22
- Only in flannel: github.com/containernetworking/plugins, github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common
- Only in k3s: github.com/k3s-io/kine, github.com/ipfs/go-ds-leveldb, MinIO, Rancher, k8s.io/apiserver, github.com/sirupsen/logrus, containerd, Kubernetes, github.com/rancher/wharfie, k8s.io/cloud-provider, Prometheus, github.com/go-logr/logr, k8s.io/cluster-bootstrap, github.com/containerd/fuse-overlayfs-snapshotter/v2, github.com/containerd/stargz-snapshotter, github.com/pdtpartners/nix-snapshotter, k8s.io/kubelet, Docker, github.com/natefinch/lumberjack, go.uber.org/zap, github.com/cloudnativelabs/kube-router/v2, github.com/containerd/zfs/v2, github.com/flannel-io/flannel, github.com/google/cadvisor/lib, github.com/ipfs/go-log/v2, github.com/Mirantis/cri-dockerd

## Side by side

| | flannel | k3s |
|---|---|---|
| Size | 19,318 lines written, 68 code files | 61,452 lines written, 244 code files |
| Who writes it | 1.8% of its commits signed by AI. With GitHub Copilot and Claude Code | 0.1% of its commits signed by AI. With Claude Code |
| Activity | Last push November 9, 2026, 1,325 commits, 9,568 stars | Last push November 14, 2026, 3,677 commits, 34,402 stars |
| Tests | 38 test files. 41.2% of its code files have a test that imports them | 107 test files. 33.2% of its code files have a test that imports them |

- Size: Lines written by people and agents, without generated ones; code files, without tests.
- Who writes it: A commit counts as AI's when it carries its signature: a Co-Authored-By line, its author name or the merge of its branch.
- Activity: From GitHub and its history, on the day SeeRepo read it.
- Tests: The files that test the code, and the share of code files a test imports.

## Frequently asked questions

### Which is bigger, flannel or k3s?

k3s, with 61,452 lines written; flannel has 19,318.

The proof: [k3s-io/k3s's code at commit c55a7df](https://github.com/k3s-io/k3s/tree/c55a7df0fc49e826072b163d2c91ab4f67f06325)

### Which has more GitHub stars, flannel or k3s?

k3s, with 34,402 stars; flannel has 9,568.

The proof: [k3s-io/k3s on GitHub](https://github.com/k3s-io/k3s)

### Which has more tests, flannel or k3s?

k3s, with 107 test files; flannel has 38.

The proof: [k3s-io/k3s's code at commit c55a7df](https://github.com/k3s-io/k3s/tree/c55a7df0fc49e826072b163d2c91ab4f67f06325)

### Which was updated more recently, flannel or k3s?

k3s: its last push was on November 14, 2026, and flannel's on November 9, 2026.

The proof: [k3s-io/k3s's commits on GitHub](https://github.com/k3s-io/k3s/commits)

### Which has more commits signed by AI, flannel or k3s?

flannel: an AI signed 1.8% of its commits, with GitHub Copilot and Claude Code; in k3s, 0.1%.

The proof: [the commits each tool signed in flannel-io/flannel](https://seerepo.com/r/flannel-io/flannel/ai)

## Sources

- flannel-io/flannel: Read on November 14, 2026, at commit dc074a9 (https://github.com/flannel-io/flannel/tree/dc074a93121c406313b7f6c2607d9ad102b6d24e)
- k3s-io/k3s: Read on November 14, 2026, at commit c55a7df (https://github.com/k3s-io/k3s/tree/c55a7df0fc49e826072b163d2c91ab4f67f06325)

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.