As a Software Developer, you have some tasks which you regularly need to take care of. Tasks like quickly compiling, running, and testing a line of code, formatting code, converting some code or exporting it as an image, editing or converting an image,… and some other similar tasks.

Therefore, I compiled a list of the free online tools I usually use for such kind of tasks.

Code Compilers

Code Compilers are quickly used to compiler your code and run it to see the results. They are so useful when you want to quickly test a piece of code and you don’t want to open a new IDE window for that purpose.

DotNetFiddle

Using DotNetFiddle, you can quickly compile and run your C#, F#, and VB.NET code.

JSFiddle

Using JSFiddle, you can quickly compile and run your JavaScript code. It supports many of JavaScript frameworks like vanilla JavaScript, CoffeeScript, Babel, TypeScript, Vue, React and more…

OnlineGDB

OnlineGDB is an online compiler and debugger tool for C, C++, Python, PHP, Ruby, C#, VB, Perl, Swift, Prolog, Javascript, Pascal,… and many other languages.

CodeChef

Using CodeChef, you can compile & run your code. The online compiler supports multiple programming languages like Python, C++, C, Kotlin, NodeJS, and many more.

IdeOne

Using IdeOne, you can quickly compile and run your code in many languages.

Code Formatters

Code Formatters are used to quickly format code into a decent format controlling spaces, indents,… and other attributes.

JSONLint

JSONLint is a validator and re-formatter for JSON, a lightweight data-interchange format. Copy and paste, directly type, or input a URL in the editor above and let JSONLint tidy and validate your messy JSON code.

SAML Developer Tools

SAML Developer Tools provides a set of tools centered around Security Assertion Markup Language (SAML). It is an XML-based, open-standard data format for exchanging authentication and authorization data between parties, in particular, between an identity provider and a service provider.

Web Formatter

Using Web Formatter, you can format your HTML, XML, CSS, JavaScript, PHP and JSON code in a few easy steps. Paste your code into the text box, select the tab spacing that you want and click the format button.

Code Beautify

Code Beautify provides a great set of different tools for developers including compilers, formatters, converters,… I would recommend to always keep it around.

Converters

Converters are used to convert code from one format to another.

Carbon

Using Carbon, you can create and share beautiful images of your source code.
Start typing or drop a file into the text area to get started.

Hilite

Hilite converts your code snippets into pretty-printed HTML format, easily embeddable into blog posts, emails and websites.

Just copy the source code to the left pane, select the language and the color scheme, and click “Highlight!”. The HTML from the right pane can now be pasted to your blog or email, no external CSS or JavaScript files are required.

Json2Csharp

Using Json2Csharp, you can convert any JSON object to a C# class.

QuickType

Using QuickType, you can convert any JSON object to an object in your preferred language.

HTML Encoder

Using HTML Encoder, you can encode text or a file as HTML-encoded text, using just your browser. View the encoded value or download it as a file.

HTML Decoder

Using HTML Decoder, you can decode text or a file from HTML-encoded text, using just your browser. View the decoded value or download it as a file.

URL Encoder/Decoder

Using URL Encoder/Decoder, you can encode or decode a URL.

Image Editors

Image Editors as used to quickly apply some edits on images or even sometimes create images from scratch. Some of these tools are so sophisticated to the extent that they provide many professional tools and capabilities like the ones provided by expert tools like Photoshop.

PhotoPea

In simple words, if you are familiar with Photoshop, you would like PhotoPea.

Pixlr

Pixlr is the No 1 photo editing and design tool. Edit photos and create stunning designs right in your browser, on your phone or desktop, for free. Start from an empty canvas, a photo, or a video or select one of the professionally crafted templates.

Lunapic

Lunapic is one of the greatest online photo editors I have seen. You can enjoy using a great set of tools and features which would help you get the job done easily.

Image Resizers

Image Resizers are used to resize an image without downgrading the image resolution and quality. Some of these tools provide capabilities to keep the background transparent and not replace it with a solid color.

ResizePng

ResizePng is the world’s simplest online Portable Network Graphics (PNG) image resizer. Just import your PNG file in the editor on the left and you will instantly get a resized PNG on the right. Free, quick, and very powerful.

ResizeImage

Using ResizeImage, you can upload an image, crop the image, rotate the image, resize the image, make background Transparent, select the output image Format, optimize your image, and finally download the final image.

Image Converters

Image Converters are used to convert images from one format to another.

Img2Go

Using Img2Go, you can convert an image from any format to another format. It provides a great set of tools to help you get the job done in simple easy steps.

Miscellaneous

In this category, you would find a list of online tools which do different things.

Regex101

Regex101 is a great tool which helps you build and verify your regular expression against test input data. Furthermore, it helps you understand and learn as it provides you with an analysis by breaking down your regular expression into parts and explaining each part.

Markup Validation Service

Markup Validation Service checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc. If you wish to validate specific content such as RSS/Atom feeds or CSS stylesheets, MobileOK content, or to find broken links, there are other validators and tools available. As an alternative you can also try our non-DTD-based validator.

PingDom

PingDom helps you analyze your website load speed.

The test is designed to help make your site faster by identifying what about a webpage is fast, slow, too big, and so on.

In short, it is an easy-to-use tool built to help webmasters and web developers everywhere optimize their website performance.

Minifier

Minifier removes whitespace, strips comments, combines files, and optimizes/shortens a few common programming patterns. And it comes with a huge test suite.

Final Words

These are some tools that I regularly use on a daily basis. If you have other tools which you really like, please feel free to share with me.

That’s it, I hope you found reading this article as interesting as I found writing it.