Claude Opus 5 vs GPT-5.6 Sol
Both are Flagship-tier models, from Anthropic and OpenAI respectively. GPT-5.6 Sol is the cheaper choice overall at a 4:1 input:output ratio.
Which is cheaper
- Input price: GPT-5.6 Sol is cheaper ($4.00 vs $5.00).
- Output price: GPT-5.6 Sol is cheaper ($20.00 vs $25.00).
- Blended, 4:1 input:output ratio: GPT-5.6 Sol is 20% cheaper ($7.20 vs $9.00 per weighted 1M tokens).
Side by side
| Spec | Claude Opus 5 | GPT-5.6 Sol |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Tier | Flagship | Flagship |
| Context window | 1M | 1.05M |
| Max output | 128K | 128K |
| Input $/1M | $5.00 | $4.00 |
| Output $/1M | $25.00 | $20.00 |
| Cache read $/1M | $0.50 | $0.40 |
| Cache write $/1M | $6.25 | $5.00 |
| Modalities | text, image | text, image |
Claude Opus 5. 5-minute cache write shown ($6.25 = 1.25x base input); 1-hour cache write is $10/MTok (2x base). Batch API is 50% off ($2.50/$12.50). Context window and max output cross-checked against platform.claude.com/docs/en/about-claude/models/overview.
GPT-5.6 Sol. Short-context rate, for prompts up to 272K input tokens. Above 272K the rate is $8 input / $30 output, cache read $0.80, cache write $10 per 1M. Promotional pricing, stated to run at least through 21 November 2026.
Sources
Claude Opus 5 — verified August 29, 2026
GPT-5.6 Sol — verified August 29, 2026
Full Claude Opus 5 pricing page → · Full GPT-5.6 Sol pricing page →