Developer Tools Directory

Browse our complete collection of fast, private, and free utilities.

JSON Tools

Format, validate, and manipulate JSON data.

JSON Formatter & Tree Viewer

Validate, format, and visualize JSON in a collapsible, interactive tree view — in real-time.

JSON → Zod Schema

Generate type-safe Zod validation schemas from any JSON object — with syntax-highlighted output.

JSON → Pydantic Model

Convert JSON to Python Pydantic BaseModel classes with nested object support — instantly.

CSV Tools

Convert and manage CSV files.

CSV ↔ JSON Converter

Convert CSV to JSON and vice-versa instantly. Handles large files with secure client-side processing.

API & Protocol Tools

Tools for working with APIs, OpenAPI, and MCP.

OpenAPI → MCP Server

Convert any OpenAPI or Swagger spec into a ready-to-run MCP server — in TypeScript or Python.

JWT Decoder & Debugger

Decode, verify, and examine JSON Web Tokens (JWT) locally. Color-coded syntax, payload analysis, and expiration timeline.

Cron Expression Generator

Generate and explain cron expressions in plain English. Interactive builder and real-time execution schedule.

AI & LLM Tools

Utilities for working with Artificial Intelligence and LLMs.

AI Token & Pricing Calculator

Calculate exact BPE tokens for massive prompts and instantly compare pricing & latency across flagship AI models.

Image Tools

Compress, resize, convert, and export images privately in your browser.

Image Compressor

Compress JPG, PNG, and WebP images locally with adjustable quality.

Image Resizer

Resize images to exact pixel dimensions while preserving aspect ratio.

Image Format Converter

Convert images between PNG, JPG, and WebP without uploading them.

Image to PDF Converter

Turn one or more images into a downloadable PDF in your browser.

Text & Content Tools

Count, clean, transform, and optimize written content.

Word & Character Counter

Count words, characters, sentences, paragraphs, and reading time live.

Text Case Converter

Convert text to uppercase, lowercase, title, sentence, camel, snake, or kebab case.

URL Slug Generator

Turn titles and phrases into clean, SEO-friendly URL slugs.

SEO & Marketing Tools

Create search metadata, campaign links, and crawler directives.

Meta Tag Generator

Generate SEO, Open Graph, and Twitter meta tags with a live preview.

Robots.txt Generator

Build a valid robots.txt file and sitemap directive in seconds.

UTM Link Builder

Add Google Analytics campaign parameters to any URL accurately.

Calculators & Converters

Fast everyday calculators and accurate unit conversions.

Percentage Calculator

Calculate percentages, percentage share, and percentage change.

Age Calculator

Calculate exact age in years, months, and days from a birth date.

BMI Calculator

Calculate body mass index and see the standard weight category.

Loan Payment Calculator

Estimate monthly payments, total interest, and total loan cost.

Unit Converter

Convert common length, weight, and temperature units instantly.

Unix Timestamp Converter

Convert Unix timestamps to readable dates and dates back to Unix time.

Security & Encoding Tools

Generate passwords, hashes, QR codes, and encoded data locally.

QR Code Generator

Create and download a QR code for any URL or text instantly.

Secure Password Generator

Generate strong customizable passwords entirely on your device.

Base64 Encoder & Decoder

Encode plain text to Base64 or decode Base64 safely in your browser.

SHA Hash Generator

Generate SHA-1, SHA-256, SHA-384, or SHA-512 hashes locally.