> ## Documentation Index
> Fetch the complete documentation index at: https://bun.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Get the process uptime in nanoseconds

Use `Bun.nanoseconds()` to get the total number of nanoseconds the `bun` process has been alive.

```ts theme={"theme":{"light":"github-light","dark":"dracula"}}
Bun.nanoseconds();
```

***

See [Docs > API > Utils](/runtime/utils) for more useful utilities.