Essential Free Online Resources for Developers

We are fortunate to have a plethora of free online development tools at our disposal, which can make our lives as developers easier. In this article, I will present the ones that I find interesting and that I wanted to share with you.

Table of Contents

Tools for regular expressions

To begin with, regular expressions are a powerful tool for developers. However, unfortunately, they can also be the bane of many developers’ existence. Crafting or correcting a regular expression can quickly become a hair-pulling experience.

Regex101 – Creating, testing, and debugging regular expressions

Regex101 is a comprehensive online tool designed to assist developers in working with regular expressions. It provides a user-friendly interface for creating, testing, and debugging regular expressions in various programming languages, including JavaScript, Python, PHP, and many others. With features like syntax highlighting, real-time matching, explanation of regex patterns, and substitution support, Regex101 simplifies the process of working with regular expressions, making it a valuable resource for both beginners and experienced developers alike.

Cyrilex – Regular Expression Tester and Visualizer

I will try to remain neutral, Cyrilex is a regular expression tester offering numerous features. Like regex101, it allows testing regex in different programming languages, including MySQL (a rare feature among competitors). It includes a pattern visualizer, which makes it easier to understand patterns. It also offers the ability to generate strings from a pattern.

Data set generators

Data generators are invaluable for creating diverse and representative data for testing purposes, ensuring robustness and accuracy in software evaluation and performance analysis.

Mockaroo – Generating realistic test data

Mockaroo is a versatile online tool designed for generating realistic test data. With Mockaroo, you can easily create customized datasets for testing purposes in various formats, including CSV, JSON, SQL, and Excel. It offers a wide range of data types and options for generating structured and randomized data, allowing you to simulate real-world scenarios accurately. Additionally, Mockaroo provides features such as data validation and custom formulas. Whether you are a developer, tester, or data analyst, Mockaroo is an invaluable resource for creating realistic test data efficiently.

Mockaroo also offers a paid version with numerous advantages and removes certain limitations. It is also available as a docker image that you can deploy in your own private cloud.

Mockium – Freely generate large datasets

Mockium enables rapid generation of test data without the need for registration or installation. Like Mockaroo, you visually define your dataset fields and select data types, with predefined types corresponding to typical client data found in datasets. You can generate dummy data files (CSV, SQL, JSON) according to your specifications. However, its advantage lies in the absence of limitations on the quantity of generated data; you can freely generate large datasets with hundreds of thousands of elements at no cost.

Playgrounds

Playgrounds serve as invaluable platforms for developers to explore and learn. They enable rapid experimentation and testing. Furthermore, they facilitate seamless sharing troubleshooting on forums (Yes, ChatGPT hasn’t killed forums yet).

Codepen.io – Test and showcase excerpts of HTML, CSS, and JavaScript code

Codepen.io serves as a collaborative platform tailored for front-end designers and developers. It enables to create and launch websites, showcase projects, create test scenarios for learning and debugging, and seek creative inspiration.

DB Fiddle – MySQL and PostgreSQL sandbox

db-fiddle.com allows to create and share SQL queries across popular database engines like MySQL, PostgreSQL, and SQLite. It offers a user-friendly interface and features for sharing code snippets.

A medley of cool tools

Codebeautify.org – The Ali Baba’s cave

Codebeautify.org offers over 100 online tools, including Code Formatters, Data Beautifiers, Viewers, Converters, and more.

Freeformatter.com – Online developer tools

Freeformatter.com also offers a multitude of online tools, including formatters, validators, converters, escapers, as well as web resources (such as a list of MIME types, URL parser, etc.).