Free Online Tools for Developers

Format, validate, and beautify your JSON data online for free.

Encode text to Base64 or decode Base64 to text instantly.

Encode or decode URLs and query parameters online.

Count words, characters, sentences, and paragraphs in your text.

Convert text between UPPERCASE, lowercase, Title Case, and more.

Convert between different units of length, weight, temperature, and more.

Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text online.

Pick colors and convert between HEX, RGB, HSL, and RGBA formats instantly.

Test and debug regular expressions with real-time matching and highlighting.

Convert Unix timestamps to human-readable dates and vice versa.

Generate random UUIDs (v4) instantly. Bulk generate up to 100 UUIDs at once.

Convert numbers between binary, octal, decimal, and hexadecimal bases.

Generate placeholder Lorem Ipsum text for your designs and mockups.

Write Markdown and preview the rendered HTML output in real-time.

Generate strong, secure random passwords with customizable length and character types.

Calculate percentages easily: what percent is X of Y, X% of Y, and percentage change.

Convert JSON data to CSV format and CSV to JSON instantly. Free online converter for developers.

Compare two texts side by side and see the differences highlighted. Free online diff checker.

Parse, validate, and generate cron expressions with a visual editor. See next scheduled run times.

Decode and inspect JSON Web Tokens (JWT). View header, payload, claims and expiration status.

Create beautiful CSS gradients with a visual editor. Copy the CSS code instantly.

Encode special characters to HTML entities or decode HTML entities back to text. Essential for web developers.

All-in-one string manipulation tool. Reverse, slugify, trim, sort lines, count characters and more.

Check WCAG color contrast ratios for accessibility. Verify AA and AAA compliance for text and background colors.

Calculate and convert aspect ratios for images, videos, and screens. Lock width or height to scale proportionally.

Generate QR codes for URLs, text, Wi-Fi passwords, and more. Customize colors, size, and error correction level.

Generate complete HTML meta tags for SEO, Open Graph, and Twitter Cards. Real-time SEO score and preview.

A customizable Pomodoro productivity timer with work sessions, short breaks, long breaks, and session tracking.