* The size and frequency of the HTTP calls your application makes. If you’re making too many calls, or your calls are too large, you should know about it!
 * The performance of these calls on the underlying network. If the network’s performance isn’t sufficient, you need to either improve the network or use less of it.

### EventListener

_2020-03-17_

**This release candidate turns on web socket compression.**

The [spec][rfc_7692] includes a sophisticated mechanism for client and server to negotiate
compression features. We strive to offer great performance in our default configuration and so we're
making compression the default for everyone starting with this release candidate.

Please be considerate of your servers and their operators as you roll out this release. Compression

}
```

Further examples are on the [OkHttp Recipes page][recipes].


Requirements
------------

OkHttp works on Android 5.0+ (API level 21+) and Java 8+.

OkHttp depends on [Okio][okio] for high-performance I/O and the [Kotlin standard library][kotlin]. Both are small libraries with strong backward-compatibility.

We highly recommend you keep OkHttp up-to-date. As with auto-updating web browsers, staying current

to connect to that server: the port number, HTTPS settings, and preferred network protocols (like HTTP/2).

URLs that share the same address may also share the same underlying TCP socket connection. Sharing a connection has substantial performance benefits: lower latency, higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-pool/)...

    security provider is installed.
 *  Fix: The previous release introduced a performance regression on Android,
    caused by looking up CA certificates. This is now fixed.


## Version 3.1.0

_2016-02-06_

 *  New: WebSockets now defer some writes. This should improve performance for
    some applications.
 *  New: Override `equals()` and `hashCode()` in our new cookie class. This

| [OpenJSSE]       |         | ✅           | [OpenJDK]       | OpenJDK backport.                                            |
| [Corretto]       | ✅      | ✅           | [OpenSSL]       | Amazon's high-performance provider. [Tracking bug.][bug5592] |

All providers support HTTP/1.1 and TLSv1.2.


[BoringSSL]: https://boringssl.googlesource.com/boringssl/
[Bouncy Castle]: https://www.bouncycastle.org/java.html

## Version 2.7.4

_2016-02-07_

 *  Fix: Don't crash when finding the trust manager if the Play Services (GMS)
    security provider is installed.
 *  Fix: The previous release introduced a performance regression on Android,
    caused by looking up CA certificates. This is now fixed.


## Version 2.7.3

_2016-02-06_

 *  Fix: Permit the trusted CA root to be pinned by `CertificatePinner`.

    prefer the JDK’s precedence order.) This change may cause your HTTP calls to negotiate a
    different cipher suite than before! OkHttp's defaults cipher suites are selected for good
    security and performance.

 *  New: `ConnectionListener` publishes events for connects, disconnects, and use of pooled
    connections.

 *  Fix: Immediately update the connection's flow control window instead of waiting for the

 *
 * When a single logical call requires multiple streams due to redirects or authorization
 * challenges, we prefer to use the same physical connection for all streams in the sequence. There
 * are potential performance and behavior consequences to this preference. To support this feature,
 * this class separates _allocations_ from _streams_. An allocation is created by a call, used for

 */
package okhttp3

/**
 * [TLS cipher suites][iana_tls_parameters].
 *
 * **Not all cipher suites are supported on all platforms.** As newer cipher suites are created (for
 * stronger privacy, better performance, etc.) they will be adopted by the platform and then exposed
 * here. Cipher suites that are not available on either Android (through API level 24) or Java
 * (through JDK 9) are omitted for brevity.
 *