What naming rules does Kubernetes enforce?

Most object names must be a valid RFC 1123 DNS label: lowercase alphanumerics and hyphens only, starting and ending with an alphanumeric, up to 63 characters. A few resources allow the longer DNS subdomain form with dots, up to 253 characters. This tool generates names that pass both checks.

Why are uppercase letters not allowed?

Kubernetes derives DNS records and labels from object names, and DNS is case-insensitive and conventionally lowercase. Names with uppercase letters or underscores are rejected by the API server, so the generator only emits lowercase letters, digits and hyphens.

What is the difference between a label and a subdomain name?

A DNS-1123 label is a single segment up to 63 characters with no dots, used by pods, services and most objects. A DNS-1123 subdomain allows dot-separated labels up to 253 characters total and is used by a smaller set of resources such as some custom resources.

Are the generated names guaranteed valid?

Yes. Each name is built from a lowercase word list joined by hyphens, then validated against the exact regular expression Kubernetes uses, and truncated to the length limit so it always starts and ends with an alphanumeric character.

Does the tool contact any server?

No. Names are generated locally in your browser with no network calls, so it works offline and nothing you generate is sent anywhere.

Kubernetes Resource Name Generator

Names the API server will accept

The Kubernetes Resource Name Generator produces object names that satisfy the validation Kubernetes applies on kubectl apply. Most resources require an RFC 1123 DNS label — lowercase, hyphen-separated, alphanumeric at both ends, 63 characters or fewer. This tool builds names that pass that rule (or the longer subdomain form) so your example manifests never get rejected.

How it works

The generator draws from curated word lists — adjectives, nouns and short technical terms — and joins them with hyphens, appending a kind-appropriate suffix (for example -svc for a service or -cm for a configmap). It then lowercases everything, strips any character outside [a-z0-9-], collapses repeated hyphens, and trims leading and trailing hyphens so the first and last characters are always alphanumeric.

Finally each candidate is matched against the exact regular expression Kubernetes uses. For a DNS-1123 label that is [a-z0-9]([-a-z0-9]*[a-z0-9])? capped at 63 characters; for a subdomain it is the dot-joined form of that label capped at 253 characters. Only names that pass are emitted, so every result is guaranteed valid.

Tips and example

A pod name comes out like calm-otter-pod; a service like bright-cache-svc; a namespace like team-payments.
Keep names short and descriptive — 63 characters is the hard limit for labels, and very long names are awkward in logs and selectors.
Use the subdomain rule only for resources that actually allow dots, such as certain custom resources; pods and services need the label form.
All names are synthetic placeholders for examples and tests — never assume one maps to a real workload.