你的浏览器还没开启 Javascript 功能!

浏览器请求耗时阶段解释

浏览器请求耗时阶段解释

Queueing

浏览器会在以下情况时将请求加入队列,有优先级更高的请求;当请求协议是 HTTP/1.0 和 HTTP/1.1 时,同一域名下已经有 6 个 TCP 链接;浏览器在分配磁盘缓存

Stalled

由于排队中描述的任何原因,请求可能会停止

DNS Lookup

浏览器正在解析请求的 IP 地址

Proxy negotiation

浏览器与代理服务器协商请求

Request sent

请求已经发出

ServiceWorker Preparation

浏览器启动 service worker

Request to ServiceWorker

请求已经向 service worker 发出

Waiting (TTFB)

浏览器等待第一个字节返回,此时间包括 1 次往返延迟和服务器准备响应所用的时间。

Content Download.

浏览器接收响应

Receiving Push.

浏览器收到通过 HTTP/2 Server Push 的响应

Reading Push.

浏览器正在读取先前收到的本地数据

Timing breakdown phases explained

Here’s more information about each of the phases you may see in the Timing tab:

Queueing.

The browser queues requests when:

  • There are higher priority requests.
  • There are already six TCP connections open for this origin, which is the limit. Applies to HTTP/1.0 and HTTP/1.1 only.
  • The browser is briefly allocating space in the disk cache

Stalled.

The request could be stalled for any of the reasons described inQueueing.

DNS Lookup.

The browser is resolving the request’s IP address.

Proxy negotiation.

The browser is negotiating the request with aproxy server.

Request sent.

The request is being sent.

ServiceWorker Preparation.

The browser is starting up the service worker.

Request to ServiceWorker.

The request is being sent to the service worker.

Waiting (TTFB)

The browser is waiting for the first byte of a response. TTFB stands for Time To First Byte. This timing includes 1 round trip of latency and the time the server took to prepare the response.

Content Download

The browser is receiving the response.

Receiving Push

The browser is receiving data for this response via HTTP/2 Server Push.

Reading Push

The browser is reading the local data previously received.