Forem: Kumar Harsh

# 🔍 Stop Guessing Your Regex — Test It Instantly (Free Tool)

Kumar Harsh — Tue, 14 Apr 2026 13:46:46 +0000

If you’ve ever worked with regex, you know the pain:

You write a pattern
It looks correct
But it doesn’t match what you expect

So you:

Tweak it
Run again
Repeat 10 times 😅

🧠 The Problem with Regex

Regex is powerful… but:

Hard to debug
Easy to break
Difficult to visualize

Even small mistakes can cause:

No matches
Wrong matches
Performance issues

⚡ The Better Way

Instead of guessing, you should test regex in real-time.

That’s exactly what a regex tester helps you do.

🚀 Try This Free Regex Tester

👉 https://toolhub.fyi/tool/regex-tester

No login. No setup.

✅ What You Can Do With It

Test regex patterns instantly
See matches highlighted
Debug complex expressions
Experiment safely

💡 Example

Let’s say you want to match emails:

^[\w.-]+@[a-zA-Z\d.-]+\.[a-zA-Z]{2,}$

Instead of guessing…

👉 Paste it into the tool
👉 Add sample text
👉 See matches instantly

🔥 Why This Saves Time

Without a tester:

Trial and error
Slow debugging

With a tester:

Instant feedback
Faster development

🧩 Common Use Cases

Developers use regex for:

Form validation
Data extraction
Log parsing
Search & replace

🧠 Pro Tip

Always test your regex before using it in production.

Even a small mistake can break your logic.

🏁 Final Thoughts

Regex doesn’t have to be painful.

Once you start testing patterns live, it becomes much easier and faster.

🚀 Try it now

👉 https://toolhub.fyi/tool/regex-tester

If you use any other regex tools, drop them below 👇

I spent 3 hours debugging a “bug” that wasn’t real. Problem? `"true"` (string) `true` (boolean). A quick JSON format revealed it instantly. Lesson: Most bugs aren’t complex — they’re hidden in messy data. Tools save time https://toolhub.fyi

Kumar Harsh — Mon, 13 Apr 2026 18:39:01 +0000

toolhub.fyi

# 🚀 10 Free Developer Tools I Use Daily (No Login, No Ads)

Kumar Harsh — Sat, 11 Apr 2026 11:37:26 +0000

As developers, we constantly deal with small but annoying tasks:

Fixing broken JSON
Testing regex
Formatting SQL queries
Decoding JWT tokens

Most tools online are either:

Slow
Filled with ads
Or require login 😑

So I started collecting (and building) fast, no-login developer tools that I actually use daily.

Here are my favorites 👇

⚡ 1. JSON Formatter (Fix messy JSON instantly)

Ever pasted JSON and got:

“Invalid JSON” error?

This tool helps you:

Beautify JSON
Validate errors
Fix formatting instantly

👉 https://toolhub.fyi/tool/json-formatter

🔍 2. Regex Tester (Debug patterns easily)

Regex can be painful.

This tool lets you:

Test patterns live
See matches instantly
Debug step-by-step

👉 https://toolhub.fyi/tool/regex-tester

🧠 3. SQL Formatter (Clean ugly queries)

Working with SQL like:

SELECT * FROM users WHERE id=1

This tool converts it into clean, readable format:

👉 https://toolhub.fyi/tool/sql-formatter

🔐 4. JWT Decoder (Understand tokens instantly)

If you work with authentication:

Decode JWT tokens
View payload clearly
No verification required

👉 https://toolhub.fyi/tool/jwt-decoder

🔄 5. JSON ↔ CSV Converter

Super useful when working with APIs or Excel.

Convert JSON → CSV
Convert CSV → JSON

👉 https://toolhub.fyi/tool/json-to-csv

🔄 6. XML ↔ JSON Converter

Still dealing with XML APIs?

Convert XML → JSON
Convert JSON → XML

👉 https://toolhub.fyi/tool/xml-to-json

🔑 7. UUID Generator

Need unique IDs?

Generate UUID instantly
No dependencies

👉 https://toolhub.fyi/tool/uuid-generator

🔒 8. Password Generator

Create strong passwords:

Custom length
Symbols, numbers, etc.

👉 https://toolhub.fyi/tool/password-generator

🔗 9. URL Encoder / Decoder

Perfect for handling query params:

👉 https://toolhub.fyi/tool/url-encode

🧾 10. Word Counter

Useful for:

Writing blogs
Counting characters

👉 https://toolhub.fyi/tool/word-counter

💡 Why I prefer these tools

⚡ Fast (no loading delays)
🔒 No data stored
🚫 No login required
💻 Works directly in browser

🧠 Final Thoughts

Instead of bookmarking 20 different sites, I prefer having everything in one place.

If you’re a developer, these tools can save you a lot of time daily.

👉 If you have any other tools you use daily, drop them below 👇

Why SHA256 is Better Than MD5

Kumar Harsh — Sun, 05 Apr 2026 18:31:24 +0000

If you're working with hashing, you’ve probably seen both MD5 and SHA256.

The key difference? Security.

MD5 is fast but outdated and vulnerable to collisions, which makes it unsafe for modern applications.

SHA256, on the other hand, is part of the SHA-2 family and provides much stronger security. It’s widely used in APIs, authentication systems, and even blockchain.

If you're building anything today, avoid MD5 and use SHA256 instead.

I also built a simple tool to generate hashes instantly if you want to try it out:
https://toolhub.fyi/tool/sha256-generator

Secure code starts with the right choices.

# Why SHA256 is Better Than MD5 If you're working with hashing, you’ve probably seen both MD5 and SHA256. The key difference? Security. MD5 is fast but outdated and vulnerable to collisions, which makes it unsafe for modern applications. SHA256, on the

Kumar Harsh — Sun, 05 Apr 2026 18:27:28 +0000

Ever opened an XML file and saw: “This XML file does not appear to have any style information…” Toolhub.fyi

Kumar Harsh — Thu, 02 Apr 2026 18:39:58 +0000

Ever opened an XML file and saw:

“This XML file does not appear to have any style information…”

Yeah, it’s annoying 😅

I made a quick tool to convert XML into clean JSON:

👉 https://toolhub.fyi/tool/xml-to-json

Let me know if it helps!

Dev tools app - toolhub.fyi

Kumar Harsh — Fri, 27 Mar 2026 18:23:26 +0000

🚀 Built a Free Dev Tools Hub (JWT, JSON, SQL, Regex, Timestamp)

Hey devs 👋

I got tired of switching between slow, cluttered tools… so I built my own.

🔧 Includes:

JSON Formatter
JWT Generator & Decoder
SQL Formatter
Regex Tester
Timestamp Converter

⚡ Fast, clean, no signup

Already getting some traffic from search (even US users 👀)

Would love your feedback:
👉 https://toolhub.fyi

What tool should I add next?

# Stop Manually Converting Timestamps (Use This Instead)

Kumar Harsh — Wed, 25 Mar 2026 18:51:41 +0000

If you’ve ever worked with APIs or backend logs, you’ve probably seen something like:

1711459200

And then you:

Open a new tab
Search “timestamp to date”
Paste it somewhere

I used to do this multiple times a day while debugging.

So I built a simple tool to fix that.

What it does

Convert timestamp → readable date
Convert date → timestamp
Supports both seconds and milliseconds

Why this is useful

When you're debugging logs or checking API responses, raw timestamps slow you down. Having a quick way to convert both directions saves time and avoids mistakes.

Example

Input:
2024-03-26 00:00:00

Output:

Timestamp (seconds): 1711411200
Timestamp (milliseconds): 1711411200000

Try it here

👉 https://toolhub.fyi/tool/timestamp-converter
https://toolhub.fyi/blog/unix-timestamp-to-date-guide

I’m building small, useful tools like this consistently.
Would love feedback on what else would help developers in daily workflows.

5 Free Tools I Use Daily as a Backend Developer (No Login, No Clutter)

Kumar Harsh — Mon, 23 Mar 2026 19:31:20 +0000

As a backend developer, I end up using small utility tools all the time.

Formatting JSON, cleaning up SQL queries, validating responses — these are tiny tasks, but they happen every day.

The problem?

Most tools are either:

slow
filled with ads
require login
or just too cluttered

So over time, I found myself sticking to a few simple, fast tools.

Here are 5 that I genuinely use daily 👇

1. JSON Formatter (Fast & Clean)

When working with APIs, raw JSON can get messy quickly.

A good formatter makes it:

readable
easier to debug
easier to spot issues

👉 I actually built a simple one for myself:
https://toolhub.fyi

It’s focused on:

speed
zero login
clean UI

2. SQL Formatter

Messy SQL = painful debugging.

Formatting queries properly helps:

understand joins faster
debug logic errors
improve readability

I use formatters almost every time I write complex queries.

3. JSON Validator

Sometimes APIs return broken or unexpected responses.

A validator helps quickly:

detect syntax errors
avoid runtime issues

4. Text Diff Checker

Comparing two responses manually is a nightmare.

Diff tools help you:

spot changes instantly
debug faster

5. Base64 Encoder/Decoder

Surprisingly useful when dealing with:

tokens
encoded payloads
API debugging

Why I Built My Own Tool Hub

I got tired of switching between multiple sites just to do simple things.

So I built a small tool hub that puts everything in one place:
👉 https://toolhub.fyi

It’s still early, but the goal is simple:

fast tools
no clutter
no login
developer-first experience

Would Love Your Feedback 🙌

If you use similar tools:

What do you use the most?
Anything you wish existed but doesn’t?

I’m actively improving it based on real feedback.