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Nithish

Nithish

Developer & Blogger , 21K Tools
India
41 Published Posts

About Nithish

Hi, I’m Nithish. I’m the guy behind 21K Tools. I got tired of online tools that were slow, full of ads, paywalled or sketchy with privacy, so we built simple free ones that actually feel good to use everything runs in your browser, no account needed (maybe someday), no tracking. I write the guides here from stuff I test and use myself. Got suggestions, problems or ideas? Just email us at contact@21k.tools or fill the form at the Help Center. Follow @21ktools on X for updates.

Published Articles

Will AI Replace Simple Online Tools in 2026? Why Dedicated Calculators and Converters Still Win for Accuracy

Will AI Replace Simple Online Tools in 2026? Why Dedicated Calculators and Converters Still Win for Accuracy

Everyone's asking whether AI will replace simple online tools like calculators and converters. As someone who builds these tools, I've tested both sides properly. Here's …

Simple Interest vs Compound Interest: What's the Difference and Why It Matters More Than You Think

Simple Interest vs Compound Interest: What's the Difference and Why It Matters More Than You Think

A plain-language, depth-first explanation of simple interest and compound interest — complete formulas, worked examples with real numbers, comparison tables, and the practical situations where …

Why Your Instagram Images Look Blurry After Upload (Exact Pixel Sizes for Every Platform in 2026)

Why Your Instagram Images Look Blurry After Upload (Exact Pixel Sizes for Every Platform in 2026)

Instagram, Facebook, LinkedIn and Twitter all compress your images after upload — and if you don't prepare for it, the results look terrible. Here's exactly …

How URL Shorteners Actually Work – And What Makes 21K Tools' Shortener Different

How URL Shorteners Actually Work – And What Makes 21K Tools' Shortener Different

A plain-language breakdown of how URL shorteners work under the hood — redirects, analytics, QR codes — plus an honest look at what 21K Tools' …

Weak 4G Is Still Normal in 2026 – Why Browser Tools Feel Like Magic on Slow Networks

Weak 4G Is Still Normal in 2026 – Why Browser Tools Feel Like Magic on Slow Networks

Most people use their phone on weak 4G more than they realise — on commutes, in rural areas, in basements. Here's why browser tools that …

How Long Does Your File Really Live on "Free" Online Converters?

How Long Does Your File Really Live on "Free" Online Converters?

Most free online converters keep your uploaded files far longer than you'd expect. A look at real retention policies, what actually happens to your documents …