GPT-5.1 vs GPT-6 Astra (US)
GPT-5.1 is cheaper than GPT-6 Astra (US) by about 83% on a blended (75% input / 25% output) basis. GPT-5.1 charges $1.25 / $10.00 per 1M input/output tokens; GPT-6 Astra (US) charges $10.00 / $50.00.
| Field | GPT-5.1 | GPT-6 Astra (US) |
|---|---|---|
| Input $/Mtok | $1.25 | $10.00 |
| Output $/Mtok | $10.00 | $50.00 |
| Cache read $/Mtok | $0.13 | $1.00 |
| Cache write $/Mtok | – | $12.50 |
| Input $/Mchar | 0.35 | 2.82 |
| Output $/Mchar | 2.82 | 14.09 |
| Context window | 400000 | 1050000 |
| Tokenizer | o200k | o200k |
| Confidence? | api | official |
| Source | openrouter | official-openai |
Confidence: official = vendor pricing page · api = OpenRouter per-host · aggregator = community list, may lag · unreviewed = automatic extraction awaiting review. When sources disagree the most authoritative wins. Details: /methodology#confidence
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 | GPT-5.1 | GPT-6 Astra (US) |
|---|---|---|
| Coding agent | $16.88 | $120.00 |
| RAG chat | $25.63 | $160.00 |
| Summarisation (batch) | $21.25 | $140.00 |
| Classification | $14.25 | $108.00 |
| Chat assistant | $47.50 | $260.00 |
| Content generation | $82.50 | $420.00 |
Cite this page
GPT-5.1 vs GPT-6 Astra (US): $1.25/$10.00 vs $10.00/$50.00 per 1M tokens as of 2026-10-04. Token Barometer by Dejan Strbad, https://tokenbarometer.com, data CC BY 4.0. https://tokenbarometer.com/compare/openai_gpt-5.1-vs-openai_gpt-6-astra