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About this tool
Design a Docker image tagging scheme from semver, git sha, branch and date parts, validated against the OCI reference rules.
This tool builds a Docker image tagging convention from the parts teams actually use — SemVer version, git branch, short commit SHA, build date and environment — and validates the result against the OCI reference grammar used by Docker (tags of at most 128 characters from letters, digits, '_', '.' and '-', never starting with '.' or '-'). It is for platform and CI engineers standardising how images are named across pipelines, so every tag is legal, sortable and traceable to a commit.
Open Docker Tag Naming Convention Builder on AltFTool — it loads instantly in your browser.
Paste your code or data sample into the workspace.
Pick the format, conversion, or analysis you need.
Copy the polished result straight back into your project.
Every part is validated against the distribution/reference rules Docker itself enforces, so the tag never fails at push time.
Slashes, spaces and other illegal characters in branch names are sanitised to hyphens automatically.
Flags mutable 'latest', untraceable tags with no SHA or version, and unusual combinations.
ASCII letters, digits, underscore, period and hyphen — the pattern [A-Za-z0-9_][A-Za-z0-9._-]* — with a maximum length of 128 characters, and the first character cannot be a period or hyphen. Anything else, including the '/' in branch names like feature/login, must be replaced before tagging.
Because 'latest' is mutable: it silently moves to whatever image was pushed most recently, so two deployments of 'latest' can run different code and rollbacks become guesswork. Immutable tags built from a version or commit SHA, or digest pinning with @sha256:, make every deployment reproducible.
Use both for different purposes: a short SHA tag (7-12 hex characters) on every CI build gives exact commit traceability, while a SemVer tag like 1.4.2 marks human-meaningful releases. Many teams push the same image with both tags, since tags are just pointers to one image digest.
No. The repository path (namespace and name) must be lowercase — components match [a-z0-9]+ separated by '.', '_', '__' or '-', with the whole path limited to 255 characters. Tags may contain uppercase letters, but repository names may not, which is why MyApp fails to push while myapp works.