With a few small exceptions (below), OkHttp 4.x is both binary- and Java source-compatible with
OkHttp 3.x. You can use an OkHttp 4.x .jar file with applications or libraries built for OkHttp 3.x.

OkHttp is **not** source-compatible for Kotlin callers, but upgrading should be automatic thanks to
Kotlin’s powerful deprecation features. Most developers should be able to use IntelliJ’s _Code
Cleanup_ for a safe and fast upgrade.

  // These are applied inside the okhttp module for that case specifically
  if (project.name != "okhttp") {
    apply(plugin = "biz.aQute.bnd.builder")
    if (project.name != "okhttp-testing-support") {
      apply(plugin = "io.github.usefulness.maven-sympathy")
    }
  }

  // Skip samples parent
  if (project.buildFile.exists() && project.name != "okhttp") {
    apply(plugin = "com.android.lint")

    who read the trailers on the `raw()` OkHttp response, after its body was decoded.


## Version 5.0.0

_2025-07-02_

This is our first stable release of OkHttp since 2023. Here's the highlights if you're upgrading
from OkHttp 4.x:

**OkHttp is now packaged as separate JVM and Android artifacts.** This allows us to offer

 *  New: Publish a [bill of materials (BOM)][bom] for OkHttp. Depend on this from Gradle or Maven to
    keep all of your OkHttp artifacts on the same version, even if they're declared via transitive
    dependencies. You can even omit versions when declaring other OkHttp dependencies.

    ```kotlin
    dependencies {
       api(platform("com.squareup.okhttp3:okhttp-bom:4.4.0"))

    cachedResponse: Response,
  ) {
  }

  /**
   * Invoked when OkHttp decides whether to retry after a connectivity failure.
   *
   * OkHttp won't retry when it is configured not to:
   *
   *  * If retries are forbidden with [OkHttpClient.retryOnConnectionFailure]. (OkHttp's defaults
   *    permit retries.)
   *  * If OkHttp already attempted to transmit the request body, and [RequestBody.isOneShot] is
   *    true.

prevent a response from using the cache, use [`CacheControl.FORCE_NETWORK`](http://square.github.io/okhttp/4.x/okhttp/okhttp3/-cache-control/-f-o-r-c-e_-n-e-t-w-o-r-k/). To prevent it from using the network, use [`CacheControl.FORCE_CACHE`](http://square.github.io/okhttp/4.x/okhttp/okhttp3/-cache-control/-f-o-r-c-e_-c-a-c-h-e/). Be warned: if you use `FORCE_CACHE` and the response requires the network, OkHttp will return a `504 Unsatisfiable Request` response.


### Canceling a Call ([....

 *  **URLConnection support has moved to the okhttp-urlconnection module.**
    If you're upgrading from 1.x, this change will impact you. You will need to
    add the `okhttp-urlconnection` module to your project and use the
    `OkUrlFactory` to create new instances of `HttpURLConnection`:

    ```java
    // OkHttp 1.x:
    HttpURLConnection connection = client.open(url);

    // OkHttp 2.x:

ciphers.

When negotiating a connection to an HTTPS server, OkHttp needs to know which [TLS versions](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-tls-version/) and [cipher suites](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-cipher-suite/) to offer. A client that wants to maximize connectivity would include obsolete TLS versions and weak-by-design cipher suites. A strict client that wants to maximize security would be limited to only the latest TLS version and strongest cipher suites....

import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension

@Flaky
@Tag("Slow")
class WebSocketHttpTest {
  // Flaky https://github.com/square/okhttp/issues/4515
  // Flaky https://github.com/square/okhttp/issues/4953
  @RegisterExtension
  var clientTestRule = configureClientTestRule()

  @RegisterExtension
  var platform = PlatformRule()

  @RegisterExtension

      .assertLogEqual("--> GET $url http/1.1")
      .assertLogEqual("Host: $host")
      .assertLogEqual("Connection: Keep-Alive")
      .assertLogEqual("Accept-Encoding: gzip")
      .assertLogMatch(Regex("""User-Agent: okhttp/.+"""))
      .assertLogEqual("--> END GET")
      .assertLogMatch(Regex("""<-- 200 OK $url \(\d+ms\)"""))
      .assertLogEqual("Content-Length: 0")
      .assertLogEqual("<-- END HTTP")
      .assertNoMoreLogs()