---
title: 'Development'
description: 'Preview changes locally to update your docs'
---
**Prerequisites**:
- Node.js version 19 or higher
- A docs repository with a `docs.json` file
Follow these steps to install and run Mintlify on your operating system.
```bash
npm i -g mint
```
Navigate to your docs directory where your `docs.json` file is located, and run the following command:
```bash
mint dev
```
A local preview of your documentation will be available at `http://localhost:3000`.
## Custom ports
By default, Mintlify uses port 3000. You can customize the port Mintlify runs on by using the `--port` flag. For example, to run Mintlify on port 3333, use this command:
```bash
mint dev --port 3333
```
If you attempt to run Mintlify on a port that's already in use, it will use the next available port:
```md
Port 3000 is already in use. Trying 3001 instead.
```
## Mintlify versions
Please note that each CLI release is associated with a specific version of Mintlify. If your local preview does not align with the production version, please update the CLI:
```bash
npm mint update
```
## Validating links
The CLI can assist with validating links in your documentation. To identify any broken links, use the following command:
```bash
mint broken-links
```
## Deployment
If the deployment is successful, you should see the following:
## Code formatting
We suggest using extensions on your IDE to recognize and format MDX. If you're a VSCode user, consider the [MDX VSCode extension](https://marketplace.visualstudio.com/items?itemName=unifiedjs.vscode-mdx) for syntax highlighting, and [Prettier](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode) for code formatting.
## Troubleshooting
This may be due to an outdated version of node. Try the following:
1. Remove the currently-installed version of the CLI: `npm remove -g mint`
2. Upgrade to Node v19 or higher.
3. Reinstall the CLI: `npm i -g mint`
Solution: Go to the root of your device and delete the `~/.mintlify` folder. Then run `mint dev` again.
Curious about what changed in the latest CLI version? Check out the [CLI changelog](https://www.npmjs.com/package/mintlify?activeTab=versions).