| Guide | What it covers |
|---|---|
| How to estimate LLM API costs | The cost formula plus the four corrections that make budget estimates real: tokenizer differences, invisible tokens, caching, deprecations. |
| The Sonnet 5 price increase that didn't happen | Anthropic announced +50% for Claude Sonnet 5 from Sept 1, 2026. The rate card still shows $2/$10. What we got wrong, and what to budget. |
The numbers these guides are built on
As of 2026-11-02, the pricing table tracks 50 models (40 active) across 3 providers, each row verified against the provider's own pricing page. The spread is the whole story: Gemini 2.5 Flash-Lite at $0.1/$0.4 per MTok and GPT-5.5 Pro at $30/$180 differ by roughly 420× on combined rate — which is why "which model" dominates every budgeting question these guides answer. The deprecation tracker adds the other axis: 129 announced retirement dates that can force a migration mid-budget-cycle.
Recent pricing events
| Date | Provider | What changed |
|---|---|---|
| 2026-12-11 | OpenAI | gpt-5 (all snapshots), gpt-5-pro, o3, o3-pro shut down — Migrate to GPT-5.5 family. |
| 2026-12-01 | OpenAI | gpt-image-1-mini, gpt-image-1.5, chatgpt-image-latest shut down — Migrate to gpt-image-2. |
Events feed from the same verified dataset as the table. Run your own numbers in the calculator.