Sanity Field Types Reference

Text Field Types

string

Use for: Short text content (titles, names, labels) Webflow examples: Name, Title, Category, Tag, Author Name Conversion:

Trims whitespace
Preserves Unicode characters
Removes null bytes

Example:

{
  "title": "My Blog Post",
  "category": "Technology"
}

Limitations:

No character limit in Sanity (but keep under 200 chars for usability)
Single line only (use text for multi-line)

text

Use for: Long plain text (descriptions, notes, excerpts) Webflow examples: Excerpt, Meta Description, Summary, Notes Conversion:

Preserves line breaks
Trims leading/trailing whitespace
Supports multi-line content

Example:

{
  "excerpt": "This is a longer description\nthat spans multiple lines\nand preserves formatting."
}

Differences from string:

Multi-line support
Usually rendered as textarea in Studio
Better for longer content

portableText

Use for: Rich text with formatting (blog posts, descriptions) Webflow examples: Post Body, Description, Content, Rich Text, Article Body Conversion:

Parses HTML structure
Converts to Portable Text blocks
Preserves formatting (bold, italic, links)
Handles headings, lists, images

Example:

{
  "content": [
    {
      "_type": "block",
      "style": "h2",
      "children": [{"text": "Introduction"}]
    },
    {
      "_type": "block",
      "children": [
        {"text": "This is "},
        {"text": "bold", "marks": ["strong"]},
        {"text": " text."}
      ]
    }
  ]
}

Learn more: HTML Conversion

Number Field Types

number

Use for: Numeric values (prices, counts, ratings, percentages) Webflow examples: Price, Quantity, Rating, Order, Count Conversion:

Parses integers and decimals
Handles thousand separators (1,000 → 1000)
Preserves decimal precision

Example:

{
  "price": 99.99,
  "rating": 4.5,
  "quantity": 100
}

Notes:

Stored as JSON number
No currency symbol (add in frontend)
Decimal precision preserved

Boolean Field Type

boolean

Use for: True/false toggles (featured, published, active) Webflow examples: Featured, Published, Active, In Stock, Visible Conversion:

CSV Value	Boolean
`true`, `True`, `TRUE`	`true`
`false`, `False`, `FALSE`	`false`
`yes`, `Yes`, `YES`, `1`	`true`
`no`, `No`, `NO`, `0`, (empty)	`false`

Example:

{
  "featured": true,
  "published": false,
  "inStock": true
}

Date/Time Field Types

datetime

Use for: Dates with time (published date, event time, timestamps) Webflow examples: Published Date, Event Date Time, Updated At Conversion:

Parses ISO 8601 format (2024-01-15T10:30:00.000Z)
Converts to UTC
Validates date range (1900-2100)

Example:

{
  "publishedAt": "2024-01-15T10:30:00.000Z",
  "eventStart": "2024-06-20T14:00:00.000Z"
}

Webflow format: Webflow exports dates like 2024-01-15T10:30:00.000Z which convert directly.

Excel corrupts dates! Don’t open CSVs in Excel—it changes the format and breaks the import.

date

Use for: Date only, no time (birth date, release date) Less common - Most use cases work better with datetime. Use this only when time component is truly irrelevant. Example:

{
  "birthDate": "1990-05-15"
}

URL Field Types

url

Use for: Web URLs, external links Webflow examples: Website, External Link, Source URL, Video URL Conversion:

Validates URL format
Preserves full URL
Accepts http:// and https://

Example:

{
  "website": "https://example.com",
  "sourceUrl": "https://webflow.com/article"
}

slug

Use for: URL-friendly identifiers (page slugs, permalinks) Webflow examples: Slug, URL Slug Conversion:

Lowercases value
Replaces spaces with hyphens
Removes special characters
Formats as Sanity slug object

Example:

{
  "slug": {
    "_type": "slug",
    "current": "my-blog-post"
  }
}

Webflow value: my-blog-post Sanity value: {current: "my-blog-post"}

Slugs are stored as objects in Sanity, not plain strings. MigrateKit handles this conversion automatically.

Asset Field Types

image

Use for: Single images (cover image, hero image, thumbnail) Webflow examples: Main Image, Hero Image, Thumbnail, Featured Image Conversion:

Downloads image from Webflow CDN URL
Checks for duplicates (reuses existing)
Uploads to Sanity assets
Creates asset reference

Example:

{
  "coverImage": {
    "_type": "image",
    "asset": {
      "_ref": "image-abc123xyz-1920x1080-jpg",
      "_type": "reference"
    }
  }
}

Supported formats: JPG, PNG, GIF, SVG, WebP

file

Use for: Documents, PDFs, downloads Webflow examples: PDF Download, Attachment, Document Conversion: Similar to images:

Downloads from URL
Uploads to Sanity
Creates reference

Example:

{
  "pdfDownload": {
    "_type": "file",
    "asset": {
      "_ref": "file-xyz789-pdf",
      "_type": "reference"
    }
  }
}

Supported formats: PDF, DOC, DOCX, XLS, XLSX, ZIP, etc.

Advanced Field Types

array

Use for: Multiple values (tags, categories, multiple images) Webflow examples: Tags (comma-separated), Gallery (multiple images) Conversion:

Splits comma-separated values
Creates array of specified type

Example (array of strings): CSV: "webflow,sanity,migration"

{
  "tags": ["webflow", "sanity", "migration"]
}

Example (array of images): CSV: "https://cdn/img1.jpg,https://cdn/img2.jpg"

{
  "gallery": [
    {"_type": "image", "asset": {"_ref": "image-abc..."}},
    {"_type": "image", "asset": {"_ref": "image-def..."}}
  ]
}

reference

Not currently supported in MigrateKit MVPReference fields (relationships to other collections) must be manually recreated in Sanity Studio after import.Workaround:

Map as string to preserve the ID/slug
Manually link references in Sanity after migration
See Limitations for details

Field Type Decision Guide

Use this flowchart to choose the right field type:

Common Mapping Patterns

Blog Post

{
  "_type": "post",
  "title": "string",
  "slug": "slug",
  "content": "portableText",
  "coverImage": "image",
  "publishedAt": "datetime",
  "featured": "boolean",
  "tags": "array of string"
}

Product

{
  "_type": "product",
  "name": "string",
  "slug": "slug",
  "description": "portableText",
  "price": "number",
  "images": "array of image",
  "inStock": "boolean"
}

Author

{
  "_type": "author",
  "name": "string",
  "slug": "slug",
  "bio": "portableText",
  "photo": "image",
  "email": "string",
  "website": "url"
}

Getting Started

CSV Migration Guide

Understanding MigrateKit

Troubleshooting

Reference

Text Field Types

string

text

portableText

Number Field Types

number

Boolean Field Type

boolean

Date/Time Field Types

datetime

date

URL Field Types

url

slug

Asset Field Types

image

file

Advanced Field Types

array

reference

Field Type Decision Guide

Common Mapping Patterns

Blog Post

Product

Author

Learn More

Field Mapping Guide

Sanity Docs

Getting Started

CSV Migration Guide

Understanding MigrateKit

Troubleshooting

Reference

​Text Field Types

​string

​text

​portableText

​Number Field Types

​number

​Boolean Field Type

​boolean

​Date/Time Field Types

​datetime

​date

​URL Field Types

​url

​slug

​Asset Field Types

​image

​file

​Advanced Field Types

​array

​reference

​Field Type Decision Guide

​Common Mapping Patterns

​Blog Post

​Product

​Author

​Learn More

Field Mapping Guide

Sanity Docs

Text Field Types

string

text

portableText

Number Field Types

number

Boolean Field Type

boolean

Date/Time Field Types

datetime

date

URL Field Types

url

slug

Asset Field Types

image

file

Advanced Field Types

array

reference

Field Type Decision Guide

Common Mapping Patterns

Blog Post

Product

Author

Learn More