Reference Tools
Quick references you reach for daily: HTTP status codes, ASCII table, MIME types and other cheat sheets.
HTTP Status Codes
HTTP status code reference — searchable list of all standard 1xx–5xx codes with names and plain-English descriptions, free online.
ASCII Table
ASCII table reference online for free — all 128 characters with decimal, hex, glyph and control-code names, searchable by any format.
Semver Checker
Check semantic versions online — parse versions, compare two releases, bump major/minor/patch/prerelease and test npm-style ranges like ^1.2 or 1.x for free.
Mail Blackhole Comparison
Free email sandbox plans compared — Mailtrap, Mailisk, Mailloop and MailSlurp vs our Mail Blackhole fake SMTP mailboxes: monthly quotas, retention, API, IMAP and webhooks.
Watchdroid Comparison
Free uptime monitoring compared — UptimeRobot, Better Stack, Healthchecks.io, StatusCake and Uptime Kuma vs our Watchdroid monitors: monitor counts, check intervals, heartbeat/cron support, alerts and status pages.