Free Online Developer Tools

Google SERP & Social Snippet Simulator

Preview how your web page appears on Google Search (desktop & mobile), Twitter / X Cards, and Facebook feeds with live pixel-width math and HTML meta generator.

RegEx Tester

Test regular expressions online free — debug regex patterns with live match highlighting, capture groups, and a built-in cheat sheet.

CSS Gradient Generator

Generate CSS gradients online free — design linear and radial multi-stop gradients with live preview and one-click CSS code copy.

CSS Box Shadow Generator

Generate CSS box shadows online free — build realistic multi-layer card shadows with blur, spread, inset, and color controls.

CSS clamp() Generator

Generate CSS clamp() values online free — calculate fluid typography and responsive spacing formulas for any viewport range.

JSON to YAML Converter

Convert JSON to YAML online free — transform JSON payloads to YAML manifests and parse YAML back to JSON instantly.

JSON to CSV Converter

Convert JSON to CSV online free — transform JSON arrays and API responses into downloadable CSV spreadsheets for Excel.

Unix Timestamp Converter

Convert Unix timestamps online free — convert epoch seconds to human-readable UTC/local dates and vice versa instantly.

IPv4 Address Converter

Convert IPv4 addresses online free — convert between binary, hex, decimal, and dotted notation. Includes reverse DNS PTR lookup.

HTML Entity Encoder / Decoder

Encode and decode HTML entities online free — safely escape special characters like <, >, & for web security and templating.

JWT Decoder

Decode JWT tokens online free — inspect JSON Web Token header, payload, and signature. Check expiration status client-side without uploading.

Cron Expression Generator

Generate cron expressions online free — build and validate cron job schedules with plain English explanations for Linux, AWS, and GitHub Actions.

CSS Glassmorphism Generator

Generate glassmorphism CSS online free — design frosted glass UI cards with backdrop blur, opacity, and border controls. Get Tailwind CSS output.

Color Contrast Checker

Check color contrast ratios online free — validate WCAG 2.2 AA and AAA accessibility standards for text and background color combinations.

SQL Formatter & Beautifier

Format SQL queries online free — beautify, prettify, and minify SQL statements with proper indentation and uppercase keyword formatting.

CIDR Subnet Calculator

Calculate CIDR subnets online free — find network address, broadcast, usable host range, and netmask for any IPv4 CIDR block.

JSON Formatter & Beautifier

Format JSON online free — pretty-print, minify, and validate JSON data. Includes tree view and syntax highlighting.

JSON Validator

Validate JSON online free — check JSON syntax, find errors, fix trailing commas, and validate JSON structure instantly.

Hash Generator

Generate cryptographic hashes online free — compute SHA-256, SHA-512, SHA-1, and MD5 checksums for any text or password locally.

Base64 Encoder / Decoder

Encode and decode Base64 online free — convert text, strings, and Unicode to Base64 and back instantly in your browser.

UUID Generator

Generate UUID v4 online free — create cryptographically random UUIDs/GUIDs for databases, APIs, and testing purposes.

SVG Wave Generator

Create customizable SVG wave dividers and background shapes with layers, gradients, and instant CSS export.

Meta Tag & OpenGraph Generator

Generate complete HTML meta tags including Open Graph and Twitter Card markup with a live social card preview.

Color Palette & Shade Generator

Generate a 10-shade color scale, harmonies, and palettes from any HEX color. Export as CSS variables or Tailwind.

HTTP Status Code Reference

Searchable directory of all HTTP status codes (1xx–5xx) with RFC definitions, common use cases, and debugging tips.

JSON Schema Validator

Validate JSON payloads against JSON Schema (Draft 7) client-side with clear error paths and instant feedback.

CSS Animated Gradient Generator

Design smooth multi-color animated CSS background gradients with customizable speeds, angles, and export code.

Mock Data & Fake JSON Generator

Generate up to 1,000 realistic dummy records with 20+ fields. Export to JSON, CSV, SQL INSERT statements, or TypeScript.

CSV Data Explorer & Chart Generator

Inspect, filter, profile, and plot CSV spreadsheets online for free. Auto-generates summary statistics, detects nulls, and renders interactive SVG charts in-browser.

Dedicated Binary & Hex Converter

Translate seamlessly between Text, Binary (Base-2), Hexadecimal (Base-16), Decimal, and Base64. Includes byte spacing, 0x prefix toggles, and bit diagnostics.