GPT-5.6 Sol Pro API Pricing
OpenAI · context window 1.1M · prices updated 2026-09-29
Where GPT-5.6 Sol Pro sits on price
At $20.00 per million output tokens, GPT-5.6 Sol Pro is a frontier tier model — 9.1× the median output price of $2.20, which puts it in the most expensive 10% of everything we track. It sits 81th cheapest of the 100 OpenAI models we track. Output costs 5.0× input, the usual spread — trim both, starting with the answer length.
Cached input is 90% cheaper. On an input-heavy workload you need roughly a 28% cache-hit rate to take 25% off the input line — reachable for chatbots and agents that resend the same system prompt and history.
What real workloads cost on GPT-5.6 Sol Pro
These three workloads are the ones teams actually run on a frontier-priced model — a $20.00/1M model is not bought for the same job as one ten times the price.
| Workload | Per request | Per month |
|---|---|---|
| Small app — 1K requests/day (500 in / 150 out) The baseline most side projects actually run at. | $0.005 | $150 |
| Coding agent — 300 sessions/day (60K in / 12K out) Multi-step loops re-read the same files; caching matters more than raw price. | $0.48 | $4320 |
| Support chatbot — 500 conversations/day (5K in / 1.4K out) Conversation history re-sent each turn — the classic prompt-caching win. | $0.048 | $720 |
Model your exact traffic in the API cost calculator — it preloads GPT-5.6 Sol Pro with caching and batch options.
GPT-5.6 Sol Pro price history
OpenAI last raised GPT-5.6 Sol Pro's output price on Sep 29, 2026 (+100% per output token), from $2.00/$10.00 to $4.00/$20.00 per 1M in/out. That is one of 2 repricings in the 58 days we have tracked it — worth knowing before you hard-code today's rate into a budget.
| Date | Input /1M | Output /1M | Output change |
|---|---|---|---|
| Aug 2, 2026 (tracking began) | $5.00 | $30.00 | — |
| Aug 21, 2026 | $2.00 | $10.00 | -67% |
| Sep 29, 2026 | $4.00 | $20.00 | +100% |
Change-points from our daily price snapshots (tracking since Aug 2, 2026; intraday moves between snapshots are not captured).
GPT-5.6 Sol Pro vs Claude Opus 5.5
The closest-priced alternative from another vendor is Claude Opus 5.5 (Anthropic) — priced within a rounding error on output, with identical input pricing. When two models land this close on price, the decision is quality on your own workload, not the price sheet: run 50 real requests through both and compare.
See Claude Opus 5.5 pricing →Cheaper alternatives
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Frequently asked questions
› How much does the GPT-5.6 Sol Pro API cost?
GPT-5.6 Sol Pro costs $4.00 per million input tokens and $20.00 per million output tokens, with cached input at $0.4 per million (90% cheaper). That works out to roughly 50,000 output tokens per dollar.
› What does the small app workload cost on GPT-5.6 Sol Pro?
Small app — 1K requests/day (500 in / 150 out) costs about $0.005 per request and $150 per month on GPT-5.6 Sol Pro. The baseline most side projects actually run at.
› What does it cost to fill GPT-5.6 Sol Pro's 1.1M context window?
Sending 1.1M of input in a single request costs $4.20 at $4.00 per million tokens — before any output. With prompt caching that same fill drops to about $0.42 on repeat requests. This is why large context windows are cheap to advertise and expensive to actually use.
› Is GPT-5.6 Sol Pro worth the price?
GPT-5.6 Sol Pro is priced in the top bracket, at $20.00 per million output tokens. It only pays off where an error is expensive — production code, legal and medical drafting, agents that take real actions. For anything routine, Claude Sonnet 4.6 at $15.00 does the same job for a fraction of the bill.