Measure HTTP response timing
Build a paste-ready command, then review its compatibility and effects before running it.
curl -o /dev/null -s -w 'dns=%{time_namelookup}s connect=%{time_connect}s total=%{time_total}s\n' <url>Complete required fields to copy the generated command.
Compatibility
Linux + macOSVerified for Linux, macOS using posix, bash, zsh syntax.
Operational knowledgereview due 2027-01-19
Requirementscurlcurl must be installed and available on PATH.Network accessThe target must be reachable from the current environment.
Version supportcurl Current supported releasesVerified for linux, macos using posix, bash, zsh syntax; consult compatibility notes for platform-specific differences.
Expected signalsdns=0.012841s connect=0.031902s total=0.118447sRepresentative successful output; values vary with the selected target and system state.
Known errorscurl: command not foundcurl is missing or is not available on PATH.
Verifycurl -o /dev/null -s -w 'dns=%{time_namelookup}s connect=%{time_connect}s total=%{time_total}s\n' {{url}}The output matches the expected target and exits without an error.Rollback noteNot required: this command is read-only and does not change system state.
Command breakdown
01curlCommandRuns the curl stage of this one-liner.
02-oOptionSelects an output file or output format for this command.
03/dev/nullArgumentPasses /dev/null to curl.
04-sOptionEnables silent or summary output for this command.
05-wOptionConfigures curl with the -w option.
06'dns=%{time_namelookup}s connect=%{time_connect}s total=%{time_total}s\n'ArgumentPasses 'dns=%{time_namelookup}s connect=%{time_connect}s total=%{time_total}s\n' to curl.
07<url>ParameterA value supplied in the Fill parameters section.
Example input
curl -o /dev/null -s -w 'dns=%{time_namelookup}s connect=%{time_connect}s total=%{time_total}s\n' https://example.com
Example output
dns=0.012841s connect=0.031902s total=0.118447s
Illustrative output — exact values vary by system and data.
Runbooks
Official sources