Identical list prices, one generation apart — what the upgrade actually changes.
gpt-5.5 · openai
gpt-5.6-sol · openai
Benchmark
| Workload Scenario | GPT-5.5 | GPT-5.6 Sol | Price Delta |
|---|---|---|---|
| 1M input tokens (raw text) | $5.00 | $5.00 | — |
| 1M output tokens (generation) | $30.00 | $30.00 | — |
| 1M tokens · 70% input / 30% output mix | $12.50 | $12.50 | — |
| Standard chat turn (4K in / 800 out, 50% cached) | $0.035 | $0.035 | — |
| Monthly scale (10K requests / day) | $10,500.00 | $10,500.00 | — |
Negative difference = GPT-5.5 is cheaper. Positive = GPT-5.6 Sol is cheaper.
Scaling Curve
Total cost of a token volume at 70/30 input/output split (uncached). Log-log scale.
Verdict
GPT-5.6 Sol is cheaper on both input and output rates, so it costs less at every input/output mix. Price alone still isn't the whole decision: capability, latency and context limits (GPT-5.5: 1.1M, GPT-5.6 Sol: 1.1M) may justify the premium for your task.
FAQ
On input, GPT-5.6 Sol is cheaper ($5.00/M vs $5.00/M). On output, GPT-5.5 is cheaper ($30.00/M vs $30.00/M). The same model is cheaper on both sides, so it wins at every mix.
A chat-style request (4,000 input + 800 output tokens, 50% cached) costs $0.035 on GPT-5.5 and $0.035 on GPT-5.6 Sol — GPT-5.5 is equal for that workload.
GPT-5.5 supports 1,050,000 tokens (128K max output); GPT-5.6 Sol supports 1,050,000 (128K max output). They are equal.