23.02.2026
4 min
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Beginning in this part of the review, I have gathered a collection of tools that are available on the Internet for web development, security, and data analysis. On the page below, you’ll see how-to’s on using utilities for the following: Working with JWTs (JSON Web Tokens) Working with MIME types Working with HTTP Status Codes Working with User-Agent Strings Working with Open Graph Data Working with OTP (One Time Password) Codes Working with QR Codes …and many other things as well! The above-mentioned services help you to check if your tokens are valid, view incoming request details, create one-time access passwords, etc., and to simulate work within a web environment – all without having to install any additional applications. This guide will be helpful for developers, DevOps engineers, Quality Assurance Engineers, and everybody else who is often required to use APIs, browsers, or web infrastructure.
A User-Agent String is typically a mess of seemingly random characters, however when broken down, you’ll find a wealth of information about the browser, OS, Device — etc. It can help you analyze logs, and perform cross-browser / cross-platform testing and compatibility testing, while eliminating many unnecessary steps and providing clarity.
If you work with two-factor authentication, sooner or later you’ll need to verify an OTP. Here, you can generate a one-time code and simply make sure the mechanism works as expected. It’s especially useful during testing or integration. No clutter — just a straightforward, simple tool that gets the job done.
Sometimes a server returns a file with the wrong content type, and that’s when strange issues start popping up. Here, you can quickly check which MIME type corresponds to a specific file extension — and vice versa. It may seem like a small detail, but it saves a lot of frustration, especially when something won’t open or isn’t handled correctly by the browser.
Sometimes you run into a 418 or 422 status code and can’t immediately remember what it means. Here, everything is collected in one place with concise explanations. It’s especially handy when debugging APIs or server responses — no need to look up the meaning every single time.
Sometimes, you may want to determine the specific code for a particular key to make keyboard shortcuts or custom event handlers — and this is one tool that makes that process easy. Simply press a key, and you’ll have all the information about that key.
If you cannot remember exactly how to use some Git commands, it is helpful to have a reference handy. This page contains all the common Git commands that we have covered so far and does not contain any theoretical explanations about Git.
This is an instant online HTML editor where you can view how your HTML will be formatted. It’s convenient to use if you just want to quickly test some formatting or create content, since you don’t have to open any other applications — everything happens directly in your web browser.
When you want a link to look clean and polished on social media, Open Graph is essential. Here, you can quickly generate the necessary meta tags and preview how everything will appear. No need to Google examples or copy snippets of code from old projects.
When two JSON files look almost identical but something still isn’t working, this tool is a real lifesaver. It highlights the differences without you having to manually inspect every field. Extremely useful during testing or when analyzing server responses — everything becomes clear at a glance.
When you receive a JWT and want to see what’s inside, this tool is a real lifesaver. Just paste the token, and you instantly get access to the payload and other details. No need to write a script or open the console.
Outlook often masks real URLs behind its own protection layer. Here, you can reveal where a link actually leads. It’s useful for reviewing emails or analyzing suspicious addresses — and it only takes a few seconds.
Need to quickly generate a QR code for a link or a piece of text — that’s it. Enter the data and get a ready-to-use image instantly. Works just as well for testing as it does for real-world use. Nothing complicated, everything is straightforward.
Quickly scan a Wi-Fi QR Code for instant connection instead of typing in a Wi-Fi password. Great for office spaces, cafe’s, and meeting locations where time is money. Fast and simple with no additional steps.
You may have to create an image before the design is complete and the layout needs an image. This tool will help you quickly create an SVG that meets your image needs for your prototype or test page.
This allows you to take a picture or capture a video directly within your web browser. It is also useful to verify if your computer has been given permission to use your camera. There are no downloads required as it works immediately once clicked on.
Replaces plain text into a standard URL slug (i.e., a string without spaces, special characters, etc.). This is useful when creating links or filenames programmatically.
