Free tools

Developer tools, free and unmetered.

Production-grade utilities built for AI engineers. No signup, no account, no usage cap. Everything runs in your browser and nothing you paste leaves it.

Open sourceProduction readyType safe

AI-Powered

Prompt Optimizer

AI-powered prompt optimization using KERNEL framework. Transform prompts with GPT-4 or rule-based analysis.

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Pro

System Prompt Builder

Visual workspace for crafting production-grade system prompts. Templates, analysis, and export for any model.

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Testing

Response Diff

Compare LLM responses side-by-side with quality metrics. Perfect for A/B testing prompts and models.

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Essential

Token Counter

Multi-model token counting with cost estimation. Calculate costs across GPT-4, Claude, Llama, and Gemini.

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Popular

JSON ⇄ TOON

Convert between JSON and Token-Optimized Object Notation. Reduce LLM costs by 40-60% with compact data representation.

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New

Prompt Library

Curated collection of high-performance prompts. Searchable templates for coding, content, analysis, and more.

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Essential

JSON Schema Generator

Visual builder for structured LLM outputs. Create schemas for OpenAI Function Calling, Claude Tools, and data extraction.

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Pro

Few-Shot Builder

Create training data for LLM fine-tuning. Build examples, validate quality, export for OpenAI, Anthropic, or custom models.

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Essential

RAG Document Chunker

Smart text splitting for RAG applications. Semantic chunking, overlap handling, export for Pinecone, Weaviate, Qdrant.

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Popular

Batch Prompt Processor

Process hundreds of inputs through one template. CSV import/export, bulk operations, perfect for testing and scale.

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Essential

Regex Pattern Tester

Test regex patterns in real-time. Validate LLM outputs, extract data, debug patterns with live highlighting.

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AI-Powered

Structured Output Playground

Test LLM structured outputs with real API calls. TypeScript/Python to JSON Schema. Guaranteed type-safe responses.

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Viral

Social Media Manager

Generate viral-worthy Twitter and LinkedIn posts for your blog articles. Multiple variations, engagement analysis, and A/B testing.

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More Tools Coming Soon

We're building more utilities for AI developers. Stay tuned!

Built for Production

Every tool is crafted with enterprise-grade standards and developer experience in mind.

Performance First

Optimized algorithms, efficient data structures, and real-time processing. Built to handle enterprise-scale workloads.

Type Safety

Written in TypeScript with comprehensive type definitions. Catch errors at compile time, not in production.

Developer UX

Intuitive interfaces, instant feedback, keyboard shortcuts. Built by developers, for developers.

Need a Custom Tool?

We build production-grade developer tools, AI utilities, and data processing pipelines tailored to your specific needs.