# Preview editor changes

Copy as Markdown[View as Markdown](/docs/editor/how-to/preview-changes.md)

***

Preview lets you check how a resource looks in EventCatalog before committing your changes.

## Start EventCatalog locally[​](#start-eventcatalog-locally "Direct link to Start EventCatalog locally")

In your catalog project, run:

```
npm run dev
```

EventCatalog usually runs at <http://localhost:3000>.

## Start the editor[​](#start-the-editor "Direct link to Start the editor")

In another terminal, run:

```
npx @eventcatalog/editor
```

The editor checks whether EventCatalog is running locally. When it detects a preview, resource pages show **Open Preview**.

## Use a custom preview port[​](#use-a-custom-preview-port "Direct link to Use a custom preview port")

If EventCatalog is running on a different port, tell the editor:

```
npx @eventcatalog/editor --eventcatalog-port 3001
```

## Open a preview[​](#open-a-preview "Direct link to Open a preview")

Open a resource in the editor and choose **Open Preview**.

The editor opens the matching resource page in the local EventCatalog site.

![Editor header with Open Preview action](data:image/png;base64,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)

## Fix missing preview links[​](#fix-missing-preview-links "Direct link to Fix missing preview links")

If preview is unavailable:

* Check that EventCatalog is running
* Check the preview port
* Restart the editor after starting EventCatalog
* Open the local EventCatalog URL directly to confirm it works

Preview is local. It does not publish your changes.
