# flk update
Update all flake inputs (creates a lockfile backup first).
```bash
flk update # apply updates
flk update --show # preview without applying
```
**Options**
- `--show`: check for updates without modifying `flake.lock`
**Behavior**
- Backs up `flake.lock` to `.flk/backups` before applying.
- Uses `nix flake update`; preview restores the original lockfile after diffing.