Evergreen guides on tokens, pricing, caching, and how to estimate LLM cost before you ship.
11 guides. Each one links to the live calculator so you can try the numbers on your own text.
All guides
- What is a token in AI?: A plain-language definition of AI tokens, why APIs bill in tokens instead of words, how counting works, and how to estimate cost before you call a model.
- What is tokenization?: How LLMs split text into tokens with subword methods like BPE, why counts differ by model family, and how Exact vs Approx labeling works in TokenCalculator.
- Exact vs Approx token counts: Why TokenCalculator labels some models Exact and others Approx, how much heuristics can drift, and how to budget safely across OpenAI, Claude, Gemini, and other providers.
- Context windows and overflow: What an LLM context window includes, why input plus output share one budget, how overflow fails, and how long-context pricing tiers change cost.
- How prompt cost is calculated: Break down input vs output pricing, cache hits, batch discounts, monthly projections, and the workflow to estimate prompt cost before you ship.
- Prompt caching explained: How prompt cache hits cut LLM input cost, when cache writes matter, which workloads benefit, and how to estimate savings in TokenCalculator before you ship.
- How LLM API pricing works: How providers bill input vs output tokens, when cache, batch, and long-context tiers change the math, and how to estimate monthly spend before you ship.
- Tokens vs words: how to convert: Why LLM APIs bill in tokens instead of words, official English conversion rules of thumb, worked examples, and when to use Exact tokenization instead of a heuristic.
- OpenAI token calculator: Count Exact OpenAI tokens in your browser with o200k-style encodings, then estimate GPT API cost with cache, batch, and monthly volume.
- Claude token calculator: Estimate Anthropic Claude tokens and API cost in TokenCalculator with honest Approx labels, cache controls, and a clear path to Anthropic’s official count_tokens API.
- Gemini token calculator: Estimate Google Gemini tokens and API cost, including Flash vs Pro tradeoffs, Approx in-browser counts, and long-context pricing tiers when published.
Pricing ranks
New pages that rank catalog rates and embed the live tools tables. Price rank only, not quality scores.
- Cheapest LLM API: Cheapest LLM API models ranked by input rate per 1M tokens, plus an example cost for 1000 input and 500 output tokens. Curated rates, not a live scrape.
- OpenAI API pricing: OpenAI API pricing per 1M tokens for GPT-5, GPT-4o, Mini, and o-series. Curated rates with a checked date and a live TokenCalculator table.
- Claude API pricing: Claude API pricing per 1M tokens for Haiku, Sonnet, and Opus. Curated Anthropic rates with a checked date and a live TokenCalculator table.
- Gemini API pricing: Gemini API pricing per 1M tokens for Flash, Flash Lite, and Pro. Curated Google rates with long context notes and a live TokenCalculator table.
- GPT vs Claude vs Gemini cost: Compare GPT, Claude, and Gemini API cost on one prompt. Token counts differ by family. Use curated rates and the TokenCalculator compare table.
- How we verify rates: TokenCalculator stamps each model with a checked date and an official source link. No live scrape. Read how verification works before you share a budget.