We’ve all been there. There’s that one task you’ve been avoiding on your todo list. It’s not even that hard, to be honest. It just involves something finicky, fiddly, and unfamiliar. Maybe it’s a particularly tricky regex or a shell script that needs written. Luckily, it’s the 21st century and there are a plethora of resources to aid coders in these tasks. May I present The Big List of Online Code Checkers:

Devops Stuff

Crontab: https://crontab.guru

mod_rewrite Rules: https://martinmelin.se/rewrite-rule-tester

Shell Scripts: https://shellcheck.net

SPF Record: https://www.spfwizard.net

Subnet Calculator: http://www.subnet-calculator.com

Runners up – local devops tools for checking syntax

Apache: apachectl configtest

Bind: named-checkconf /etc/named.conf

Nginx: nginx -t -c conf/nginx.conf

Postfix: postfix check

SSH: sshd -t – Use this every time if you don’t want to get locked out :)

Coding Playgrounds

These are great for spiking on a solution in a less-familiar language.

Collaborative Editor: http://collabedit.com

Elixir: http://elixirplayground.com

Go: https://play.golang.org

Javascript/CSS/HTML: https://jsfiddle.net

PHP: https://www.tehplayground.com

Python: https://mathcs.holycross.edu/~kwalsh/python

Regular Expressions: https://rubular.com

Ruby: http://rubyfiddle.com

Sass: https://www.sassmeister.com

SQL: https://sqlfiddle.com

Online Code Checkers, Formatters & Converters

CSS validator: https://jigsaw.w3.org/css-validator/

HAML to ERB converter: https://haml2erb.org

HTML Tidy: https://infohound.net/tidy/

HTML validator: https://validator.w3.org

Javascript Minifier: https://jscompress.com

JSON validator/formatter: https://jsonformatter.curiousconcept.com

RSS/Atom validator: https://validator.w3.org/feed/

YAML: http://www.yamllint.com


robots.txt: Google Webmaster Tools

Structured Data: https://developers.google.com/structured-data/testing-tool/

XML Sitemap Generator: https://www.xml-sitemaps.com

This is just a small sampling of what’s available. There are online code checkers, validators, converters, formatters, and generators for just about anything you can imagine. Next time you find yourself with a dreaded task in

What online code checkers, formatters, or generators do you use on a regular basis?