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📦 Compress PDF 🔗 Merge PDF 🗜️ Compress Image 🏦 EMI Calculator ⚖️ BMI Calculator { } JSON Format 🔢 Word Counter 🎯 Regex Tester
50+ Free Tools
100% Free Forever
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Everything You Need, Organized

Six powerful categories. One unified platform.

🔥 Most Popular

The tools our users reach for every single day.

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🔥 Popular

Compress PDF

Reduce PDF file size without losing quality. Perfect for email and uploads.
🔗
🔥 Popular

Merge PDF

Combine multiple PDF files into one. Drag to reorder before merging.
🗜️
🔥 Popular

Compress Image

Shrink images up to 90% without visible quality loss. JPG & PNG supported.
🏦
🔥 Popular

EMI Calculator

Calculate monthly loan EMI, total interest and amortization schedule instantly.
{ }
⭐ Top Dev

JSON Formatter

Format, validate and minify JSON with syntax highlighting and error detection.
⚖️
❤️ Health

BMI Calculator

Check your Body Mass Index with health category and personalized advice.
🔢
Text

Word Counter

Count words, characters, sentences and paragraphs with reading time estimate.
🗑️
2 Modes

Remove PDF Page

Delete a single page or multiple pages from a PDF. Visual page picker included.
🎯
⭐ Top Dev

Regex Tester

Test regular expressions with live match highlighting and capture group display.
📐
Image

Image Resizer

Resize images to exact pixel dimensions or by percentage. Maintain aspect ratio.
📝
Text

Markdown Previewer

Live preview and export Markdown with syntax highlighting and HTML export.
💧
❤️ Health

Water Intake Tracker

Track your daily water intake with reminders and a beautiful progress display.
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How It Works

Three steps to get your work done in seconds.

1

Pick a Tool

Browse categories or search by keyword. Find exactly what you need in seconds.

2

Upload or Paste

Drag and drop your file or paste your text. No waiting — processing starts immediately.

3

Download or Copy

Get your results instantly. Download your file or copy the output with one click.

💎 Why KoTool

Built for Speed, Privacy & Simplicity

We do things differently — and our users notice.

🔒

100% Private

All processing happens directly in your browser. Your files never leave your device. We never upload, store or share your data.

⚡

Instant Results

No waiting for uploads or server queues. Our client-side tools process files in milliseconds, directly on your machine.

🆓

Completely Free

All 50+ tools are free — no freemium tricks, no file size limits hidden behind paywalls, no credit card required.

📱

Works Everywhere

Optimized for desktop, tablet and mobile. Use it on any device, in any browser, on any operating system.

🚀

No Installation

Nothing to download or install. Open your browser, go to kotool.app, and start working. That's it.

🎨

Beautiful & Intuitive

A clean, modern interface designed for efficiency. Every tool is simple enough to use without instructions.

🔄

Live Preview

Text and developer tools update in real-time as you type. See results before committing to any action.

💾

Saves Your History

Recently used tools are saved locally so you can jump back in anytime. Your history, your privacy.

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❓ FAQ

Frequently Asked Questions

Everything you need to know about KoTool.

Yes, every single one of our 50+ tools is completely free to use. There are no premium tiers, no credit card requirements, no hidden limits. KoTool is funded by non-intrusive advertising so that we can keep serving you for free.
Completely. All processing for PDF and image tools happens directly in your browser using JavaScript. Your files are never uploaded to any server — they never leave your device. We cannot see, access, or store your files.
No account required. Just open any tool and start working. KoTool remembers your recently used tools locally in your browser, but no personal information is ever collected or stored on our servers.
Since all processing happens in your browser, there are no server-side file size limits. However, very large files (100MB+) may be slower depending on your device's available memory and CPU. For most everyday files (under 50MB), processing is near-instant.
Yes! KoTool is designed mobile-first. Every tool works on smartphones and tablets, with touch-friendly interfaces including drag-and-drop for mobile devices.
The Remove PDF Page tool offers two modes: Delete Single Page — enter a page number and that page is removed; and Delete Multiple Pages — a visual thumbnail grid of all pages appears and you can select multiple pages using checkboxes, then remove them all at once.
The Medication Reminder tool uses your browser's Web Notifications API. Reminders are stored locally and trigger browser notifications. You need to grant notification permission when prompted. The tool works offline once loaded.
KoTool supports all modern browsers: Google Chrome (recommended), Mozilla Firefox, Microsoft Edge, Apple Safari, and Opera. Internet Explorer is not supported.