All tools run locally · No data sent to servers

Free Online Tools for
Developers & Builders

A curated collection of fast, free, and privacy-first developer tools. Format JSON, convert timestamps, encode Base64, generate QR codes, and more.

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16
Online Tools
100%
Client-side
Free
No registration

All Tools

Click any tool to get started instantly — no login required.

Live

JSON Formatter

Format, validate, and minify JSON with real-time syntax checking and error highlighting.

  • Real-time syntax validation
  • Beautify with custom indentation
  • Minify & compress JSON
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Live

Timestamp Converter

Convert Unix timestamps to human-readable dates and back, across multiple timezones.

  • Timestamp ↔ datetime conversion
  • Multiple timezone support
  • ISO 8601, RFC 2822 formats
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Live

Base64 Encoder/Decoder

Encode text or files to Base64 and decode Base64 strings. Supports URL-safe and MIME formats.

  • Text & file encoding
  • URL-safe Base64 support
  • Auto-detect decode mode
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Live

QR Code Generator

Create custom QR codes for URLs, WiFi, contacts, and text. Download as PNG or SVG.

  • URL, WiFi, Contact types
  • Custom colors & sizes
  • PNG & SVG download
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Live

URL Encoder/Decoder

Encode special characters for URLs using percent-encoding and decode them back.

  • encodeURI / encodeURIComponent
  • Character encoding details
  • Data type detection
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Live

Password Generator

Generate cryptographically secure random passwords with custom length and character sets.

  • Crypto-secure randomness
  • Real-time strength meter
  • Batch generation (up to 20)
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Live

SEO Analyzer

Paste your HTML source to get an SEO score, keyword analysis, and actionable optimization tips.

  • SEO score (0–100)
  • 13 SEO checks performed
  • Keyword density analysis
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Live

Image Compressor

Compress JPG, PNG, and WebP images locally in your browser. No upload to servers.

  • Adjustable quality (10–100%)
  • Format conversion (WebP/JPEG/PNG)
  • Batch processing & download
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Live

Hash Generator

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or any file.

  • MD5, SHA-1, SHA-256, SHA-512
  • Hash text or file input
  • All processing done locally
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Live

UUID Generator

Generate UUID v4 (random) and v7 (timestamp-sortable) identifiers, single or in bulk.

  • UUID v4 (RFC 4122)
  • Batch up to 100 UUIDs
  • Uppercase / lowercase / braces
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Live

Color Converter

Convert colors between HEX, RGB, HSL, and RGBA formats with a visual picker.

  • HEX, RGB, HSL, RGBA, HSLA
  • Visual color picker
  • Recent color history
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Live

Markdown Preview

Write Markdown and see the rendered HTML output in real-time. Export as HTML.

  • Live split-pane preview
  • GitHub Flavored Markdown
  • Toolbar for quick formatting
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Live

JSON Schema Validator

Validate JSON data against JSON Schema in real-time with error highlighting and schema generation.

  • Real-time dual editor validation
  • Error path highlighting & fix hints
  • Schema generator from JSON data
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Live

Timezone Converter

Compare multiple world timezones with a live clock, 24-hour timeline, and meeting time planner.

  • Up to 6 timezone cards
  • 24-hour timeline visualization
  • Best meeting time finder
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Live

CSS Gradient Generator

Create stunning linear, radial, and conic gradients with live preview and multi-language code export.

  • Linear, radial & conic gradients
  • CSS, SCSS, Tailwind & React code
  • Preset library & animation
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Live

Regex Tester

Test regular expressions with real-time highlighting, match groups, replace/split, and code generation.

  • Real-time match highlighting
  • Replace, split & group details
  • JS, Python, Java, PHP code gen
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100% PrivateAll tools run locally in your browser. No data is ever sent to our servers.