DEV Community: Harish Kumar

7 Useful Online Tools Every Developer Should Keep Handy

Harish Kumar — Thu, 27 Aug 2026 23:45:45 +0000

Developers spend a lot of time solving small problems that don't necessarily require writing a complete script or installing another application.

Converting units, checking JSON, counting words, generating secure passwords, or quickly calculating percentages are examples of tasks that can interrupt your workflow.

Here are seven simple browser-based tools that can be useful for everyday development and productivity.

JSON Formatter

When working with APIs, configuration files, or backend responses, JSON can quickly become difficult to read when it is minified.

A [JSON formatter](https://allyoutools.in/tools/json-formatter) can turn something like this:

{"name":"Alex","age":25,"skills":["JavaScript","Python"]}

into a much easier-to-read structure:

{
"name": "Alex",
"age": 25,
"skills": [
"JavaScript",
"Python"
]
}

For quick formatting and checking, you can use this online JSON Formatter.

Unit Converter

Unit conversions appear in more places in software development than you might expect.

Depending on the project, you may need to convert:

Kilometers to miles
Celsius to Fahrenheit
Kilograms to pounds
Bytes to larger storage units
Inches to centimeters

Instead of doing every conversion manually, a browser-based unit converter can be useful for quick checks.

Word Counter

Writing documentation, README files, blog posts, application descriptions, or technical guides often involves keeping track of word count.

A word counter can quickly show the number of words and characters in a piece of text without requiring a separate editor.

You can use an online word counter when you need a quick count.

Percentage Calculator

Percentages appear frequently in analytics, pricing, statistics, and everyday programming tasks.

For example, calculating a percentage increase:

Percentage Increase =
(New Value - Original Value) / Original Value × 100

For quick calculations, an online percentage calculator can help verify your result.

Password Generator

When creating test accounts or temporary credentials, developers sometimes need random passwords.

A password generator can create combinations that are difficult to guess and can be useful when you don't want to manually invent a password.

For testing purposes, you can use a password generator directly in your browser.

For production authentication systems, however, passwords should generally be handled using your application's established security practices rather than relying on a website to manage credentials.

Age Calculator

Age calculations can become surprisingly complicated when dates, leap years, and different month lengths are involved.

For simple date-related checks, an age calculator can save a little time when you need to verify an age from a date of birth.

Compound Interest Calculator

Developers building financial applications may need to test different interest-rate and investment scenarios.

The basic compound-interest formula is:

A = P(1 + r/n)^(nt)

where:

P = principal
r = annual interest rate
n = number of compounding periods per year
t = time

A compound interest calculator can be useful for checking calculations while developing or testing a financial application.

Final Thoughts

Not every development problem requires another package, command-line utility, or custom script.

For small repetitive tasks, having a collection of simple browser-based utilities can save time and reduce unnecessary context switching.

The important thing is to use the right tool for the task and verify important calculations independently when accuracy matters.

If you're looking for a collection of calculators and utilities in one place, Allyoutools provides several browser-based tools for calculations, text processing, conversions, and developer-related tasks.

How to Validate and Format JSON Before Using It in Your API

Harish Kumar — Thu, 27 Aug 2026 23:43:15 +0000

Working with APIs often means dealing with JSON. Most of the time, JSON is straightforward to read and write, but a small syntax mistake can make an otherwise correct API request fail.

A missing comma, an extra bracket, or an incorrectly quoted key can be enough to cause a parsing error.

Here are a few simple ways to validate and format JSON before using it in your application.

What Makes JSON Valid?

JSON has a relatively simple structure. Objects use curly brackets {}, arrays use square brackets [], and property names must be enclosed in double quotes.

For example:

{
"name": "John",
"age": 25,
"skills": ["JavaScript", "Python", "SQL"]
}

This is valid JSON.

A common mistake is using single quotes:

{
'name': 'John'
}

That's valid in some programming-language contexts, but it isn't valid JSON. JSON requires double quotes for strings and property names.

Check Commas and Brackets

Another common problem is a missing comma between properties.

Incorrect:

{
"name": "John"
"age": 25
}

Correct:

{
"name": "John",
"age": 25
}

The same applies to arrays and nested objects. When JSON becomes large, manually finding these mistakes can become frustrating.

Format JSON to Make It Readable

Minified JSON is useful when transferring data, but it isn't particularly comfortable to read:

{"name":"John","age":25,"skills":["JavaScript","Python"]}

Pretty-printed JSON is much easier to inspect:

{
"name": "John",
"age": 25,
"skills": [
"JavaScript",
"Python"
]
}

Formatting doesn't change the actual data. It simply makes the structure easier to understand.

For quick checks while working with API responses or configuration files, I use a browser-based JSON Formatter to format and inspect JSON without setting up another development environment.

Validate JSON Before Sending an API Request

If you're working with JavaScript, JSON can also be validated programmatically.

For example:

const jsonString = { "name": "John", "age": 25 };

try {
const data = JSON.parse(jsonString);
console.log("Valid JSON:", data);
} catch (error) {
console.error("Invalid JSON:", error.message);
}

JSON.parse() attempts to convert the JSON string into a JavaScript object.

If the JSON is invalid, JavaScript throws an error that you can catch and handle.

Don't Confuse JSON With JavaScript Objects

This is another common source of confusion.

A JavaScript object can look like this:

const user = {
name: "John",
age: 25
};

JSON representation would be:

{
"name": "John",
"age": 25
}

They look similar, but they're not exactly the same thing.

JSON is a data-interchange format with stricter syntax rules.

A Simple JSON Debugging Workflow

When an API request fails because of a JSON-related error, I generally check things in this order:

Check whether all brackets are closed.
Check commas between properties.
Make sure property names use double quotes.
Check string values for incorrect quotes.
Check nested objects and arrays.
Parse the JSON to see whether the syntax is valid.
Format the JSON so the structure is easier to inspect.

This simple checklist catches many common problems before they turn into longer debugging sessions.

Conclusion

JSON itself isn't complicated, but small syntax mistakes can be difficult to spot when you're working with large payloads.

Formatting and validating JSON before sending an API request can make debugging considerably easier. Whether you're working on a REST API, configuration file, frontend application, or backend service, keeping your JSON readable and valid is a useful habit.

For quick browser-based formatting and inspection, you can use the Allyoutools JSON Formatter.