Tag / cost optimization

Which LLM APIs are actually free to call in 2026 — not free chat apps or expiring trial credits. Verified free tiers, real rate limits, and the data catch.

The $/M input/output sticker hides cache-write premiums, a tokenizer tax, context surcharges, invisible reasoning tokens, and more. Ten verified costs, with proofs.

In 2026 the biggest lever on your LLM bill isn't which model. It's how hard the model thinks: reasoning tokens bill as output, and most models think by default.

There is no single cheapest LLM API. The winner depends on your workload shape. Verified $/M prices for classification, chat, coding, RAG, batch, and reasoning.

Caveman mode strips filler from Claude's output. The 65% headline is real for output tokens. Here's what it actually saves on your monthly bill.

Anthropic charges 10% of input for cache reads, with a 1.25x write fee. OpenAI auto-caches above 1024 tokens. The math changes which LLM is cheapest -- here is when.