# tag

<!---MARKER_GEN_START-->
Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

### Aliases

`docker image tag`, `docker tag`


<!---MARKER_GEN_END-->

## Description

A full image name has the following format and components:

`[HOST[:PORT_NUMBER]/]PATH`

- `HOST`: The optional registry hostname specifies where the image is located.
The hostname must comply with standard DNS rules, but may not contain
underscores. If the hostname is not specified, the command uses Docker's public
registry at `registry-1.docker.io` by default. Note that `docker.io` is the
canonical reference for Docker's public registry.
- `PORT_NUMBER`: If a hostname is present, it may optionally be followed by a
registry port number in the format `:8080`.
- `PATH`: The path consists of slash-separated components. Each
component may contain lowercase letters, digits and separators. A separator is
defined as a period, one or two underscores, or one or more hyphens. A component
may not start or end with a separator. While the
[OCI Distribution Specification](https://github.com/opencontainers/distribution-spec)
supports more than two slash-separated components, most registries only support
two slash-separated components. For Docker's public registry, the path format is
as follows:
  - `[NAMESPACE/]REPOSITORY`: The first, optional component is typically a
user's or an organization's namespace. The second, mandatory component is the
repository name. When the namespace is not present, Docker uses `library`
as the default namespace.

After the image name, the optional `TAG` is a custom, human-readable manifest
identifier that is typically a specific version or variant of an image. The tag
must be valid ASCII and can contain lowercase and uppercase letters, digits,
underscores, periods, and hyphens. It cannot start with a period or hyphen and
must be no longer than 128 characters. If the tag is not specified, the command uses `latest` by default.

You can group your images together using names and tags, and then
[push](https://docs.docker.com/engine/reference/commandline/push) them to a
registry.

## Examples

### Tag an image referenced by ID

To tag a local image with ID "0e5574283393" as "fedora/httpd" with the tag
"version1.0":

```console
$ docker tag 0e5574283393 fedora/httpd:version1.0
```

### Tag an image referenced by Name

To tag a local image "httpd" as "fedora/httpd" with the tag "version1.0":

```console
$ docker tag httpd fedora/httpd:version1.0
```

Note that since the tag name is not specified, the alias is created for an
existing local version `httpd:latest`.

### Tag an image referenced by Name and Tag

To tag a local image with the name "httpd" and the tag "test" as "fedora/httpd"
with the tag "version1.0.test":

```console
$ docker tag httpd:test fedora/httpd:version1.0.test
```

### Tag an image for a private registry

To push an image to a private registry and not the public Docker registry you
must include the registry hostname and port (if needed).

```console
$ docker tag 0e5574283393 myregistryhost:5000/fedora/httpd:version1.0
```