Free tools
AI tools that actually decide things
Instant, no-signup utilities for people building with AI — the numbers behind the buying decision, not another listicle.
17 free tools · no signup · web-verified & dated
Start hereThe Frontier IndexThe state of the AI frontier in one place — cheapest models to run, biggest context windows, and how far open weights undercut proprietary APIs. The editorial read the calculators build on.OpenCost calculators
- Calculator
AI Agent Cost Calculator
What does running an AI agent actually cost? Models the context that compounds every step — the reason multi-step agents cost far more than single calls — across GPT, Claude & Gemini.
Open tool - Calculator
Prompt Caching Savings Calculator
How much does prompt caching cut your LLM input bill? Set your reused-prompt size and cache-read discount to see monthly cost with vs without caching — provider-agnostic.
Open tool - Calculator
AI Subscription vs API
Is ChatGPT Plus / Claude Pro worth it, or is the API cheaper for you? Enter your usage to see the monthly cost both ways and the exact break-even.
Open tool - Calculator
AI API Cost Calculator
Estimate your monthly API spend across GPT-4o, Claude, and Gemini from your own usage — ranked cheapest-first.
Open tool - Calculator
Build vs Buy: Local-AI Payback
Enter your monthly API spend → see when an RTX 5090, 4090, or Mac Studio pays for itself vs paying per-API.
Open tool
Side-by-side comparisons
- Table
AI Model Comparison
Context windows, prices, modality, and open-weights status for every major model — filterable, side by side.
Open tool - Table
AI Subscription Comparison
ChatGPT vs Claude vs Gemini vs Perplexity vs Grok — every consumer plan by price, models, and limits.
Open tool - Table
AI Image Generation Cost
Midjourney, DALL·E, Imagen, Ideogram, Leonardo, Firefly + free self-host — by subscription, per-image, and rights.
Open tool - Table
AI Coding Assistant Comparison
Cursor, Copilot, Claude Code, Windsurf, Cline, Zed + more — by price, billing model, and features.
Open tool
Hardware & model pickers
- Calculator
How Much Unified Memory Do You Need?
16 GB or 24 GB? Unified memory is shared with the OS, so a 16 GB Mac never gives a model 16 GB. See the honest minimum and which machines fit.
Open tool - Checker
Local-LLM GPU Checker
Pick your GPU (or enter VRAM) and see exactly which open LLMs you can run locally — and at which quantization.
Open tool - Picker
Which AI Model Should I Use?
Answer a few questions about your use case and budget, get a top pick plus two alternatives with the reasoning.
Open tool - Recommender
What GPU Do I Need?
Pick the model you want to run → the minimum GPU (or Mac) that runs it locally, plus every card that fits.
Open tool - Calculator
Fine-Tuning VRAM Calculator
How much GPU memory to fine-tune a model? Full vs LoRA vs QLoRA side by side, with the minimum GPU each needs.
Open tool
Tokens & context
- Counter
Token Counter
Paste any text → exact GPT / Claude / Gemini token count, words, characters, per-model context-window fit, and the cost to send it. Runs in your browser.
Open tool - Converter
Tokens ↔ Words Converter
How many words is 1M tokens? Convert tokens to words, words to tokens, or either to characters, and see how much fits in an 8K–1M context window. The quick estimate; for an exact count of specific text, use the Token Counter.
Open tool - Calculator
Context Window Calculator
Will your document fit? Words, pages, or tokens → which models can hold it in one context window, and the cost.
Open tool
Go deeper
The guides behind the numbers. Read the concept, then run the tool.