Reference
Lookup pages for the things you check while using the tools: what a status code means and what to do about it, how to write a cron schedule, a regex that is known to work, and the right Content-Type for a file. In English.
HTTP Status Codes
Every status code you are likely to meet in one table, with causes, fixes and example responses for the ones people run into most.
49 codes, 15 guidesCron Cheatsheet
The five fields, the special characters, and ready-made schedules written out for crontab, GitHub Actions, Kubernetes, systemd, AWS and Quartz.
Syntax, 12 schedulesRegex Cheatsheet
Regular expression syntax on one page, and tested patterns for emails, URLs, IP addresses, UUIDs and more, written out for six languages.
Syntax, 16 patternsMIME Types
Which Content-Type to send for a file or a request body, with the extensions, the parameters and how to send each common type with curl and fetch.
67 types, 14 guidesHTTP Compression
Which content types to send with gzip or Brotli and which to leave alone, measured on real samples, with nginx, Apache and Caddy settings.
12 type groups, 3 servers