Anthropic: Claude Sonnet 5.5 vs OpenAI: GPT-5.1
OpenAI: GPT-5.1 is cheaper than Anthropic: Claude Sonnet 5.5 by about 14% on a blended (75% input / 25% output) basis. Anthropic: Claude Sonnet 5.5 charges $2.000000 / $10.000000 per 1M input/output tokens; OpenAI: GPT-5.1 charges $1.250000 / $10.000000.
| Field | Anthropic: Claude Sonnet 5.5 | OpenAI: GPT-5.1 |
|---|---|---|
| Input $/Mtok | $2.000000 | $1.250000 |
| Output $/Mtok | $10.000000 | $10.000000 |
| Cache read $/Mtok | $0.200000 | $0.125000 |
| Cache write $/Mtok | $2.500000 | – |
| Input $/Mchar | n/a | 0.352142 |
| Output $/Mchar | n/a | 2.817139 |
| Context window | 1000000 | 400000 |
| Tokenizer | claude | o200k |
Price history
Same workload, monthly cost
Illustrative monthly cost at 10M tokens/month, split per workload preset. Not a substitute for the calculator, which uses your own volume, cache and batch assumptions.
| Workload | Anthropic: Claude Sonnet 5.5 | OpenAI: GPT-5.1 |
|---|---|---|
| Coding agent | $24.00 | $16.88 |
| RAG chat | $32.00 | $25.63 |
| Summarisation (batch) | $28.00 | $21.25 |
| Classification | $21.60 | $14.25 |
| Chat assistant | $52.00 | $47.50 |
| Content generation | $84.00 | $82.50 |
Cite this page
Anthropic: Claude Sonnet 5.5 vs OpenAI: GPT-5.1: $2.000000/$10.000000 vs $1.250000/$10.000000 per 1M tokens, as of 2026-10-04 (Token Barometer, https://tokenbarometer.com/compare/anthropic_claude-sonnet-5-5-vs-openai_gpt-5.1).
Anthropic: Claude Sonnet 5.5 page | OpenAI: GPT-5.1 page | Open in calculator