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About ToolHub

About ToolHub

ToolHub is a collection of free online web tools accessible to everyone without registration or payment. We offer tools spanning image processing, PDF handling, developer utilities, design, and unit conversion.

Complete Privacy

Every tool on ToolHub processes data entirely in your browser — no server involved. Files you upload (images, PDFs) and data you enter never leave your device. Nothing is stored on our servers. When you close your browser tab, all processed data is gone.

Free to Use

All features on ToolHub are completely free, with no sign-up required and no usage limits. There are no watermarks on generated output. The service is sustained by advertising revenue; we do not charge users directly.

Available Tools

Image

  • Image Compressor & Converter — Reduce image and photo file size in your browser. Compress JPG, PNG, and WebP and convert formats with no upload—shrink files for email and web with minimal quality loss.
  • Image Resizer · Social Media Crop — Crop and resize for Instagram, YouTube, and blog specs. Preset ratios avoid awkward crops—processed locally in your browser.

Docs · PDF

  • Combine & Merge PDF · Split — Merge PDFs in order or split pages locally in your browser. Files never leave your device—free, no install, for contracts and reports.
  • PDF to JPG Converter · Image ↔ PDF — Extract PDF pages to JPG/PNG or bundle images into a PDF. Set DPI for sharp output—files processed locally, never uploaded.

Developer

  • JSON Formatter & Converter — Format, validate, and convert JSON to CSV or YAML in one view. Debug APIs and config files locally—free, nothing sent to a server.
  • Base64 Encoder & Decoder — Encode and decode text or images to Base64 for Data URLs and API tests. RFC-style conversion in your browser—private and free.
  • Diff Checker / Text Compare — Compare two texts or code snippets line by line or by character. Spot contract and config changes—paste stays local, no upload.
  • Regex Tester & Cheat Sheet — Test regex patterns live with flags and a cheat sheet. Parse emails, URLs, and logs—pattern and sample text never leave the browser.
  • URL Encoder & Decoder — Encode or decode URLs with encodeURIComponent for UTF-8 and special chars. Fix broken query strings—processed locally, free.

Design

  • Color Palette Generator — Build harmonious palettes and copy HEX, RGB, and HSL. Check WCAG contrast and export CSS or Tailwind tokens—all in your browser.
  • SVG Image Converter — Export SVG vectors to PNG or JPG at any scale. Keep transparency or set a background—local conversion, no server upload.
  • CSS Box-Shadow Generator — Dial blur, spread, offset, and color to build box-shadow CSS with live preview. Copy inset shadows—free, no install required.
  • CSS Gradient Generator — Preview linear and radial gradients and copy background CSS. Set angle and color stops for cards and buttons—in your browser.
  • CSS clamp() Calculator — Generate responsive clamp(min, preferred, max) for font-size and spacing. Fluid sizing without extra media queries—copy one line.

Convert · Calc

  • Unit Converter — Convert length, weight, temperature, area, and data units instantly. Metric vs imperial for travel, cooking, and dev—free in-browser.
  • Loan & Interest Calculator (Compound · FX) — Loan repayment, compound interest, and exchange rates in one place. Compare equal-payment vs equal-principal schedules and savings—inputs stay on your device.
  • Percent Calculator — Calculate discounts, ratios, and percent change instantly. Reverse sale price and savings—no spreadsheet, free in your browser.
  • Date & D-Day Calculator — Count days to a target date (D-day), find the difference between two dates, or add and subtract days. Free, in your browser.
  • Age Calculator — Enter a birth date to get your exact age, plus your zodiac sign and the days until your next birthday. Free, in your browser.
  • Pyeong Calculator (Pyeong ↔ m²) — Convert between pyeong (the Korean area unit) and square meters both ways, or get pyeong from width × height. Free, in your browser.
  • BMI Calculator — Calculate your BMI from height and weight and see whether you're underweight, normal, overweight, or obese—plus your healthy weight range. Free, in your browser.

Generate

  • QR Code Generator — Create QR codes for URLs, text, contacts, and Wi-Fi; download PNG or SVG. Tips for scan-friendly design—generated locally, free.
  • Password Generator & Strength Checker — Generate strong passwords and score strength in real time. Length and charset options—credentials created only in your browser.

Text

  • Character Counter — Count characters, words, lines, and UTF-8 bytes as you type. Hit SNS and SMS limits before you post—text stays in the browser.
  • Case Converter — Convert to UPPER, lower, Title, camelCase, snake_case, and kebab-case. Rename variables and files—processed only in your browser.

Technology

ToolHub is built with Next.js 14 App Router as a fully static site. It uses TypeScript and Vanilla CSS, deployed on Render Static Site for fast, cold-start-free delivery.

Contact

For questions or suggestions, please visit our Contact page.