GPT-5.6 Sol — API Pricing & Benchmarks
GPT-5.6 Sol is OpenAI's flagship reasoning model, released in 2026-07. The API costs $4.00 per 1M input tokens and $20.0 per 1M output tokens ($8.00 blended at a 3:1 ratio), with cached input at $0.40. It supports a 1.1M-token context window. On the independently measured Artificial Analysis Intelligence Index it scores 60.9, ranking #5 of 68 models tracked on this site, with a median output speed of 81 tokens/sec. Pricing was cut on 2026-08-21 (previously $5.00/$30.0 per 1M tokens).
Explore provider routes and additional benchmark sources for GPT-5.6 Sol
| Provider | OpenAI |
| Input price / 1M tokens | $4.00 |
| Output price / 1M tokens | $20.0 |
| Cached input / 1M tokens | $0.40 |
| Blended price (3:1) | $8.00 |
| Context window | 1.1M |
| Max output tokens | 128K |
| Knowledge cutoff | 2026-02 |
| License | proprietary |
| Input modalities | T+I |
| Output speed (tok/s) | 81 |
| Released | 2026-07 |
| Artificial Analysis Intelligence Index | 60.9 |
| LMArena Elo | 1455 |
| GPQA Diamond | 94.1% |
| Humanity's Last Exam | 49.5% |
Where GPT-5.6 Sol fits
On a blended 3:1 basis GPT-5.6 Sol costs $8.00 per 1M tokens, cheaper than 14% of the 80 priced models in this index. As OpenAI's flagship it is aimed at the hardest workloads — complex reasoning, agentic coding and multi-step tool use — where output quality dominates cost. Cached input is priced at $0.40 (90% below standard input), which rewards prompt structures with long stable prefixes — see our caching guide.
Price history
| Period | Input $/1M | Output $/1M | Cached $/1M |
|---|---|---|---|
| 2026-07-18 → 2026-08-21 | $5.00 | $30.0 | $0.50 |
| 2026-08-21 → current | $4.00 | $20.0 | $0.40 |
List-price changes recorded by this site. The full dataset is public: price-history.json (CC BY 4.0).
Alternatives at a similar price
- Claude Opus 5 (Anthropic) — $10.0/1M blended, AA Index 63.1
- Claude Opus 4.8 (Anthropic) — $10.0/1M blended, AA Index 57.3
- Claude Opus 4.7 (Anthropic) — $10.0/1M blended, AA Index 55
- Claude Opus 4.6 (Anthropic) — $10.0/1M blended, AA Index 44.9
Compare GPT-5.6 Sol
About OpenAI
OpenAI builds the GPT series. GPT-6 Astra (September 2026) sits at the top at $10/$50, and beneath it the GPT-5.6 generation ships in three sizes — Sol, Terra and Luna — that share the same 1.05M-token context window and tooling, so teams can move workloads between price points without changing integration code.