Free · No Signup · Instant

AI Developer Tools
That Actually Help

Count tokens, calculate API costs, compare models side by side, and craft the perfect system prompt — all in your browser, all free.

Count Tokens Now Estimate API Costs
4
Free Tools
11+
AI Models
0
Signups Required
100%
Client-Side
Advertisement
The Toolkit

Everything You Need
to Work Smarter with AI APIs

Practical tools built for developers, prompt engineers, and AI product teams.

Token Counter
Paste any text and instantly see how many tokens it uses across GPT-4o, Claude, and Gemini models. Know your token budget before you hit send.
Open Tool →
API Cost Calculator
Enter your token counts and monthly request volume to get exact cost breakdowns across every major model. See which model fits your budget before you scale.
Open Tool →
Model Comparison
Side-by-side specs for GPT-4o, Claude Opus, Gemini 2.5 Pro, and every major model. Context windows, pricing, capabilities — sortable and filterable.
Open Tool →
System Prompt Builder
Fill in role, context, tasks, and constraints — get a properly formatted system prompt for Claude (XML tags), GPT-4o (Markdown), or Gemini. Start from 4 ready-made templates.
Open Tool →
Advertisement
Why Use These Tools

Built for the Way
Developers Actually Work

Instant Results
All calculations happen in your browser. No API calls, no waiting, no rate limits. Paste and see results in milliseconds.
Privacy First
Your text never leaves your browser. Nothing is sent to a server. Use it safely with proprietary code and internal documents.
Always Up to Date
Pricing, context windows, and model specs updated as models release. We track OpenAI, Anthropic, and Google model changes.
Common Questions

What is AI Token Tools?

AI Token Tools is a free collection of developer utilities for working with large language model APIs. The suite includes a token counter, API cost calculator, model comparison table, and system prompt builder — all client-side, all free.

Do I need an account to use these tools?

No. Every tool runs entirely in your browser using JavaScript. There is no account, no email, no sign-up. Just open the tool and start using it.

Which AI models do you support?

All tools support OpenAI (GPT-4o, GPT-4.1, GPT-4o mini, o3, o4-mini), Anthropic (Claude Opus 4.7, Claude Sonnet 4.6, Claude Haiku 4.5), and Google (Gemini 2.5 Pro, Gemini 2.5 Flash, Gemini 2.0 Flash). We update when new models release.

How accurate is the token counter?

The token counter uses a BPE approximation that matches cl100k_base (used by GPT-4o and Claude) to within ±5% for most English text. For code and non-English languages, there may be slightly more variance. For exact counts, call the model's API tokenizer directly.

Is my text kept private?

Yes. All processing happens in your browser using JavaScript. Your text is never sent to any server by this site. We use Cloudflare Analytics (cookieless, no personal data) for basic traffic metrics only.

Advertisement