About AI Tools Kit
Free, open tools built by developers, for developers working with AI
Our Mission
AI Tools Kit was built to solve real problems developers face daily when working with large language models. Calculating token costs, optimizing prompt lengths, understanding how different models tokenize text, and reducing API payload sizes are tasks every AI developer deals with. These challenges shouldn't require switching between multiple tools and documentation pages—that's frustrating and inefficient.
We created AI Tools Kit to provide free, accurate, and fast utilities so developers can focus on building great AI applications instead of guessing at token counts and costs. The tools are designed to be lightweight, privacy-respecting (no text is stored or sent to any server), and always free. Our goal is to lower the barrier to entry for AI development and help every developer optimize their usage.
What We Offer
Token Calculator
Real-time token counting across multiple AI models (GPT-4, GPT-4o, Claude 3, Claude 3.5, Gemini Pro, Llama 3, and more). Helps developers estimate API costs before making requests and optimize prompt engineering workflows.
Token Visualizer
Visual breakdown of how text gets split into tokens by different tokenizers. Understand why certain words use more tokens and how to write more token-efficient prompts.
Lost in the Middle Analyzer
Based on the research paper "Lost in the Middle: How Language Models Use Long Contexts," this tool helps you understand positional bias in LLM context windows and optimize document ordering in RAG systems.
Word-to-Token Estimator
Quick estimation tool that converts word counts to approximate token counts across different models, useful for planning content that fits within context windows.
TOON Converter
Token Optimized Object Notation (TOON) is a compact format that reduces JSON payload sizes by up to 50%, directly reducing token usage and API costs for structured data.
AI Pricing Calculator
Compare real-time pricing across OpenAI, Anthropic, Google, Meta, and other AI providers. Calculate costs for different usage patterns and find the most cost-effective model for your use case.
Prompt Library
Curated, tested prompts for common developer tasks organized by category. Each prompt includes usage notes and customization guidance.
RAG Tools
Utilities for developers building Retrieval-Augmented Generation systems, including chunk size optimization, vectorization visualization, and context window planning tools.
Our Approach
Privacy-first
All text processing happens in-browser. No user text is stored, logged, or transmitted to external servers. Your data stays on your device.
Accuracy
Token counts use official tokenizer libraries (tiktoken for OpenAI models, etc.) running client-side via WebAssembly where possible to ensure accuracy.
Always free
Core tools will always remain free for the developer community. We believe essential utilities shouldn't have paywalls.
Open and transparent
Pricing data is sourced directly from provider documentation and updated regularly. We're transparent about how tools work and where they have limitations.
Built By
AI Tools Kit was built by a developer who works with AI systems daily and got tired of switching between multiple tools and documentation pages to answer simple questions like "how many tokens is this prompt?" and "what will this API call cost me?" The frustration of toggling between OpenAI's documentation, Claude's pricing page, and various token counting approximations led to building these tools for the entire developer community.
Every tool on this site was built with the developer experience in mind—fast, accurate, and genuinely useful for real work.
Get in Touch
Have feedback about our tools? Found a bug or want to suggest a feature? We'd love to hear from you.
Contact: hello@aitoolskit.io