| --- |
| page_title: uuid - Functions - Configuration Language |
| description: The uuid function generates a unique id. |
| --- |
| |
| # `uuid` Function |
| |
| `uuid` generates a unique identifier string. |
| |
| The id is a generated and formatted as required by |
| [RFC 4122 section 4.4](https://tools.ietf.org/html/rfc4122#section-4.4), |
| producing a Version 4 UUID. The result is a UUID generated only from |
| pseudo-random numbers. |
| |
| This function produces a new value each time it is called, and so using it |
| directly in resource arguments will result in spurious diffs. We do not |
| recommend using the `uuid` function in resource configurations, but it can |
| be used with care in conjunction with |
| [the `ignore_changes` lifecycle meta-argument](/language/meta-arguments/lifecycle#ignore_changes). |
| |
| In most cases we recommend using [the `random` provider](https://registry.terraform.io/providers/hashicorp/random/latest/docs) |
| instead, since it allows the one-time generation of random values that are |
| then retained in the Terraform [state](/language/state) for use by |
| future operations. In particular, |
| [`random_id`](https://registry.terraform.io/providers/hashicorp/random/latest/docs/resources/id) can generate results with |
| equivalent randomness to the `uuid` function. |
| |
| ## Examples |
| |
| ``` |
| > uuid() |
| b5ee72a3-54dd-c4b8-551c-4bdc0204cedb |
| ``` |
| |
| ## Related Functions |
| |
| * [`uuidv5`](/language/functions/uuidv5), which generates name-based UUIDs. |
