Partial content
Edit pageLast modified: 06 February 2025Required dependencies: io.ktor:ktor-server-partial-content
Server example: download-file, client example: client-download-file-range
Native server support: ✅
The PartialContent plugin adds support for handling HTTP range requests used to send only a portion of an HTTP message back to a client. This plugin is useful for streaming content or resuming partial downloads.
PartialContent has the following limitations:
Works only for
HEADandGETrequests and returns405 Method Not Allowedif the client tries to use theRangeheader with other methods.Works only for responses that have the
Content-Lengthheader defined.Disables Compression when serving ranges.
Add dependencies
To use PartialContent, you need to include the ktor-server-partial-content artifact in the build script:
implementation("io.ktor:ktor-server-partial-content:$ktor_version")implementation "io.ktor:ktor-server-partial-content:$ktor_version"<dependency>
<groupId>io.ktor</groupId>
<artifactId>ktor-server-partial-content-jvm</artifactId>
<version>${ktor_version}</version>
</dependency>Install PartialContent
To install the PartialContent plugin to the application, pass it to the install function in the specified module. The code snippets below show how to install PartialContent...
... inside the
embeddedServerfunction call.... inside the explicitly defined
module, which is an extension function of theApplicationclass.
import io.ktor.server.engine.*
import io.ktor.server.netty.*
import io.ktor.server.application.*
import io.ktor.server.plugins.partialcontent.*
fun main() {
embeddedServer(Netty, port = 8080) {
install(PartialContent)
// ...
}.start(wait = true)
}import io.ktor.server.application.*
import io.ktor.server.plugins.partialcontent.*
// ...
fun Application.module() {
install(PartialContent)
// ...
}The PartialContent plugin can also be installed to specific routes. This might be useful if you need different PartialContent configurations for different application resources.
To learn how to use PartialContent to serve a file using HTTP range requests, see the File section.