Test you website response time from the Linux command line with CURL.
Total website response time
Use the following command to get a total response time
, in seconds.
$ curl -s -w %{time_total}\\n -o /dev/null http://www.shellhacks.com
Sample output:
0,117
Brief options description:
Option | Description |
---|---|
-s | Quiet mode. Don’t show progress meter or error messages |
-w | Defines what to display on stdout after a completed and successful operation |
-o | Write output to ‘/dev/null’ |
time_total | The total time, in seconds, that the full operation lasted |
Detailed timing of a website response
The following command returns lookup
, connect
, pretransfer
, starttransfer
time in seconds and the total time
that the full operation lasted.
$ curl -s -w '\nLookup time:\t%{time_namelookup}\nConnect time:\t%{time_connect}\nPreXfer time:\t%{time_pretransfer}\nStartXfer time:\t%{time_starttransfer}\n\nTotal time:\t%{time_total}\n' -o /dev/null http://www.shellhacks.com
Sample output:
Lookup time: 0,004 Connect time: 0,022 PreXfer time: 0,022 StartXfer time: 0,068 Total time: 0,125
Brief options description:
Option | Description |
---|---|
Lookup time (time_namelookup) | The time, in seconds, it took from the start until the name resolving was completed |
Connect time (time_connect) | The time, in seconds, it took from the start until the TCP connect to the remote host was completed |
PreXfer time (time_pretransfer) | The time, in seconds, it took from the start until the file transfer was just about to begin. This includes all ‘pre-transfer’ commands and negotiations that are specific to the particular protocol(s) involved |
StartXfer time (time_starttransfer) | The time, in seconds, it took from the start until the first byte was just about to be transferred. This includes ‘time_pretransfer’ and also the time the server needed to calculate the result |
More detailed timing of a website response
The following command adds appconnect
and redirect
time in seconds, to the previous report. These options are available in a latest versions of CURL.
$ curl -s -w '\nLookup time:\t%{time_namelookup}\nConnect time:\t%{time_connect}\nAppCon time:\t%{time_appconnect}\nRedirect time:\t%{time_redirect}\nPreXfer time:\t%{time_pretransfer}\nStartXfer time:\t%{time_starttransfer}\n\nTotal time:\t%{time_total}\n' -o /dev/null http://www.shellhacks.com
Sample output:
Lookup time: 0,003 Connect time: 0,020 AppCon time: 0,000 Redirect time: 0,000 PreXfer time: 0,020 StartXfer time: 0,963 Total time: 1,001
Brief options description:
Option | Description |
---|---|
AppCon time (time_appconnect) | The time, in seconds, it took from the start until the SSL/SSH/etc connect/handshake to the remote host was completed (Added in 7.19.0) |
Redirect time (time_redirect) | The time, in seconds, it took for all redirection steps include name lookup, connect, pretransfer and transfer before the final transaction was started. ‘time_redirect’ shows the complete execution time for multiple redirections. (Added in 7.12.3) |
Use --version
to see if your CURL supports these options.
$ curl --version
Response Times: The 3 Important Limits
Short note for your information.
- 0.1 second – is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result;
- 1.0 second – is about the limit for the user’s flow of thought to stay uninterrupted, even though the user will notice the delay. Normally, no special feedback is necessary during delays of more than 0.1 but less than 1.0 second, but the user does lose the feeling of operating directly on the data;
- 10 seconds – is about the limit for keeping the user’s attention focused on the dialogue. For longer delays, users will want to perform other tasks while waiting for the computer to finish, so they should be given feedback indicating when the computer expects to be done. Feedback during the delay is especially important if the response time is likely to be highly variable, since users will then not know what to expect.
отличная статья! спасибо
thank you very much, this was incredibly useful.
Awesome!
Nice work!
But you should mention a catch:
Curl doesn’t follow any redirects in this case.
Imagine a heavy PHP-Site. You may end up measuring just the time the http-https-redirect needs, which stems from apache. So PHP isn’t involved at all.
Thank you very much, the article helped a lot!!!
where can we use command ? to check server response time?