💻
Developer Resources
Four groups: code hosting, documentation, communities, and the small utilities that end up pinned in your bookmarks bar. Hosting covers both international and domestic platforms — use international ones for open-source collaboration, switch when network conditions or private repositories require it, and keep default branches in order if you mirror across both. Documentation is for looking things up, not for reading end to end; jump straight to the specific API or flag. Community sites are valuable mostly for their archive of past questions and pitfalls, so search before you post. The utilities group is the smallest and the most used: compatibility tables, regular expressions, JSON formatting, architecture sketches.
Appinn
Curated reviews of free Windows, Android and macOS utilities — a reliable place to hunt for lab and research software
URL Encoder / Decoder
Online percent-encoding tool: standard mode (encodeURIComponent, RFC 3986) and form mode (application/x-www-form-urlencoded, space becomes +) convert as you type, with character/UTF-8 byte stats, an escape map and local history — 100% in-browser, nothing is uploaded
Regex Lab
Online regex tester like RegExr: real-time highlighted matches, group details, $1 replacement preview, syntax cheat sheet and step-by-step explanation
Cron Expression Generator
Build cron expressions online: presets for every minute / hour / day / week / month, plus custom fields supporting *, step values */n, ranges a-b and lists, validated as you type with a live preview of the next 10 runs in your local time zone, one-click copy, pure client-side calculation
JSON.cn
JSON formatter & validator
Can I use
Browser compatibility tables
Excalidraw
Hand-drawn style whiteboard
Shields.io
Badges for open-source projects