Prompt caching cost savings
Guide · sources linked inline · 2026-10-26
When many requests share the same prefix (system prompt, tool definitions, a long document), providers can bill the repeated part at a lower cached-input rate.
Cached vs normal input price
| Model | Input /1M | Cached /1M | Discount |
|---|---|---|---|
| GPT-6 Astra | $10 | $1 | 90% |
| GPT-6.1 Sol | $2 | $0.1 | 95% |
| GPT-6 Sol | $2 | $0.2 | 90% |
| GPT-6 Luna | $0.1 | $0.01 | 90% |
| GPT-5.6 Sol | $4 | $0.4 | 90% |
| GPT-5.6 Terra | $2 | $0.2 | 90% |
| GPT-5.6 Luna | $0.2 | $0.02 | 90% |
| GPT-5.5 | $5 | $0.5 | 90% |
| GPT-5.4 | $2.5 | $0.25 | 90% |
| GPT-5.4 mini | $0.75 | $0.075 | 90% |
| GPT-5.4 nano | $0.2 | $0.02 | 90% |
| GPT-5 mini | $0.25 | $0.025 | 90% |
| GPT-4.1 | $2 | $0.5 | 75% |
| GPT-4o mini | $0.15 | $0.075 | 50% |
| o4-mini | $1.1 | $0.275 | 75% |
| Claude Fable 5.1 | $10 | $0.25 | 98% |
| Claude Opus 5.5 | $4 | $0.2 | 95% |
| Claude Opus 5 | $5 | $0.5 | 90% |
| Claude Sonnet 5.5 | $2 | $0.1 | 95% |
| Claude Sonnet 5 | $2 | $0.2 | 90% |
| Claude Sonnet 4.6 | $3 | $0.3 | 90% |
| Claude Haiku 5.5 | $0.1 | $0.01 | 90% |
| Claude Haiku 4.5 | $1 | $0.1 | 90% |
| Gemini 4 Argon | $2 | $0.1 | 95% |
| Gemini 3.8 Flash | $0.75 | $0.075 | 90% |
| Gemini 3.6 Flash | $0.75 | $0.075 | 90% |
| Gemini 3.5 Flash-Lite | $0.3 | $0.03 | 90% |
| Gemini 3.1 Pro Preview | $2 | $0.2 | 90% |
| Gemini 3.1 Flash-Lite | $0.25 | $0.025 | 90% |
| Gemini 2.5 Pro | $1.25 | $0.125 | 90% |
| Gemini 2.5 Flash | $0.3 | $0.03 | 90% |
| Gemini 2.5 Flash-Lite | $0.1 | $0.01 | 90% |
| Grok 4.7 | $2 | $0.5 | 75% |
| Grok 4.3 | $1.25 | $0.2 | 84% |
| Grok Build 0.1 | $1 | $0.2 | 80% |
Things to know
- Anthropic also charges to write to the cache: 1.25× input for a 5-minute cache, 2× for a 1-hour cache (source). Caching only pays off when the prefix is reused.
- Put stable content first and the variable user message last so the prefix matches.
- In our calculator, enter the share of input that is a repeated prefix as “Cached input %”.
Next step → Try caching % in the calculator
Prices last checked 2026-10-26 against official sources · how we verify
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