JSON to Scala Case Class Generator

About the JSON to Scala

Generate Scala case classes from JSON, with circe decoders and encoders or Play JSON formats in the companion objects. Field names match your JSON keys exactly.

Key features

• Scala case classes from any JSON sample
• circe semi-auto decoders and encoders, or Play JSON formats
• Option[T] fields with None defaults
• Int vs Long chosen from your values
• Field names match JSON keys exactly (backticks where needed)
• Companion objects with implicit codecs

Scala case classes from JSON

Scala services built on http4s, Akka HTTP, Pekko or Play typically decode JSON into case classes. Paste a sample and get case classes with codecs for circe or Play JSON.

Example

[
  { "user_id": 7, "name": "Ada", "nickname": "ada", "score": 4.5 },
  { "user_id": 8, "name": "Alan", "nickname": null, "score": 3 }
]

import io.circe.{Decoder, Encoder, Json}
import io.circe.generic.semiauto.{deriveDecoder, deriveEncoder}

final case class User(
  user_id: Int,
  name: String,
  nickname: Option[String] = None,
  score: Double
)

object User {
  implicit val decoder: Decoder[User] = deriveDecoder
  implicit val encoder: Encoder[User] = deriveEncoder
}

val users = io.circe.parser.decode[List[User]](json)

Libraries

Tips

• camelCase fields: with circe-generic-extras, configure Configuration.default.withSnakeCaseMemberNames and rename fields freely.
• Dates: change String to java.time.Instant; circe and Play both include codecs for it.
• Big numbers: use BigDecimal for money.

Related tools

Generating for the JVM in other languages? See JSON to Java and JSON to Kotlin.

How to use the JSON to Scala

1. Paste your data into the input box, upload a file, or click Sample to try it out.
2. Adjust the options above the editor if you need to (indentation, delimiter, and so on).
3. The Scala appears instantly in the output panel. Any errors are shown with their line and column.
4. Click Copy to copy the result, or Download to save it as a file.