In practice, it depends on the workload and the model tier:
OpenAI is usually cheaper for simple, bursty, or unpredictable reuse, because cached input is typically discounted and there’s often no separate cache-write charge on newer models.openaiopenai
Claude is often cheaper for heavy reuse of a large, stable prefix—for example, long system prompts, RAG context, or agent loops—because cached reads are very cheap, at about 0.1× the normal input price, even though cache creation costs more.anthropic
Rule of thumb
Few repeated calls or irregular timing: OpenAI tends to win.
Many repeated calls over a stable prefix: Claude often wins.
Same model capability tier matters a lot: a cheaper cache rate does not always mean lower total cost if the base model price is higher.
Why the answer is not one-size-fits-all
Claude’s caching has a write premium—about 1.25× for a 5-minute cache or 2× for a 1-hour cache—but then reads are very cheap.anthropic OpenAI’s caching is generally simpler operationally and usually cheaper when the cache is only hit a few times, but its discount is often smaller on older or mid-tier setups.openaiopenai
Practical bottom line
If you want the lowest cost for lots of repeated reuse of the same prefix, Claude often comes out cheaper.
If you want the best economics for light or unpredictable reuse, OpenAI is usually cheaper in practice.
If you’re deciding for a real workload, the best comparison is to plug in your own:
prompt size,
expected cache hit rate,
reuse frequency,
and model prices.
That usually determines the winner more than the cache mechanism alone.
Differences
1 notable difference (1 contradiction)
across 3 models.
contradiction · critical
OpenAI prompt caching write cost
OpenAI has no separate cache-write charge
OpenAI
“not charge separately for cache writes or storage”
Restated, not moved: The consensus shifted from stating OpenAI is usually cheaper in default practice to clarifying that neither is universally cheaper. It adds explicit mathematical breakdowns, details on OpenAI's tiered cache read discounts (0.1x to 0.5x) vs. Claude's write premiums/5-minute window, and broader workload nuances.
Refined the pricing comparison to clarify that both providers offer similar cache read discounts (~90%) and that total cost differences often stem from underlying base model prices, while maintaining the same core conclusions regarding which provider to choose for different workload patterns.
3 AI models
answered this question independently on 2026-08-11. A judge from a different model family
then cross-checked the answers, scored how far they agree and flagged where they differ. The question is re-checked weekly, and every earlier version stays on this page.
AI models can make mistakes – verify important information against the sources above.
