Format converter migrates [[Properties#Deprecated properties|deprecated property formats]] to the current format used by Obsidian.
> [!warning] Back up your vault
> Conversion applies to your entire vault. [[Back up your Obsidian files]] before you start.
To convert the properties in your notes:
1. Open the [[Command palette]].
2. Select **Format converter: Frontmatter migration**.
3. Select **Start conversion**.
## Supported property formats
The converter updates aliases, tags, and CSS classes from deprecated formats:
**Aliases**
```yaml
# Before
alias: My Note Title
# After
aliases:
- My Note Title
```
**Tags**
```yaml
# Before
tag: project, important
# After
tags:
- project
- important
```
**CSS Classes**
```yaml
# Before
cssclass: custom-style
# After
cssclasses:
- custom-style
```