what OpenAI API actually costs in 2026
gpt-5.6-sol: $4.00 in / $20.00 out per 1M tokens · gpt-5.6-luna: $0.20 in / $1.20 out
not using prompt caching for repeated system prompts/context is the most common source of overspend for small teams building LLM features.
what companies your size actually pay
We have read no OpenAI API invoices so far, which is fewer than the five we require before publishing a range. Until then this page shows published list pricing only, above.
the levers that work
- cached input tokens are billed at 10x lower rate ($0.40 vs $4.00 for flagship) — reusing prompts/context via caching is the biggest lever
- using the smaller mini-class model (gpt-5.6-luna) for simple tasks is 20x cheaper than the flagship model
- batch API pricing is roughly half of standard synchronous pricing for non-latency-sensitive workloads
Across the audits we have run, roughly 30% of a small company's OpenAI API line is recoverable without changing provider.
the closest alternatives, priced
| provider | published price | source |
|---|---|---|
| Anthropic Claude Haiku 4.5 | $1.00 in / $5.00 out per 1M tokens | link |
| Google Gemini Flash | sub-$1 per 1M tokens for smaller models (varies) | link |
A published price is not a quote. In a full audit we email the alternative as a disclosed agent for your company and get a real price for your exact usage — which is the number your incumbent actually responds to.
see what the rest of your stack should cost.
Drop last quarter's invoices. We name every line you are overpaying, with an annualized amount, free. The full audit is $299 once: it gets a real quote from the alternative for your exact usage and runs the renegotiation with your incumbent until there is an answer. If it does not identify at least $2,990/yr, we refund it in full.
start an auditOpenAI API is a trademark of its owner. SpendAudit is not affiliated with, endorsed by or a reseller for any vendor on this page. Prices are the vendor's own published figures, checked 25 Aug 2026, and change without notice.