By the toolist.ai editors. Researched from the providers' own pricing pages, not hands-on tested by toolist.ai. Prices checked October 6, 2026; we re-check them every week.
AI model API prices and comparisons
Of the newest OpenAI and Anthropic models, GPT-6.1 Sol and GPT-6 Sol are the cheapest at $2 per million input tokens and $10 per million output tokens. GPT-6 Astra and Claude Fable 5.1 are the most expensive at $10 and $50. The table shows what each one costs for the same support chatbot workload, so you can compare a month's bill, not just a token price.
API price table
| Model | Input | Cached input | Output | Context window | Released | Support chatbot, a month |
|---|---|---|---|---|---|---|
| GPT-6.1 Sol OpenAI | $2 | $0.10 | $10 | 1.05M | 2026-09-29 | $1,000 |
| Claude Opus 5.5 Anthropic | $4 | $0.20 | $20 | 1M | 2026-09-22 | $2,000 |
| GPT-6 Sol OpenAI | $2 | $0.20 | $10 | 1.05M | 2026-09-22 | $1,000 |
| GPT-6 Astra OpenAI | $10 | $1 | $50 | 1.05M | 2026-09-03 | $5,000 |
| Claude Fable 5.1 Anthropic | $10 | $0.25 | $50 | 1M | 2026-09-01 | $5,000 |
| Claude Opus 5 Anthropic | $5 | $0.50 | $25 | 1M | 2026-07-24 | $2,500 |
USD per million tokens at standard rates, newest model first. Support chatbot: 100,000 replies, each 3,000 input and 400 output tokens, no caching. Each model's page lists long-context, batch and fast-mode prices.
Price your own workload
| Model | Cost a month |
|---|---|
| GPT-6.1 Sol | $150 |
| Claude Opus 5.5 | $300 |
| GPT-6 Sol | $150 |
| GPT-6 Astra | $750 |
| Claude Fable 5.1 | $750 |
| Claude Opus 5 | $375 |
Standard API prices, no batch or priority discounts. Cached input is billed at the cache-read price; cache-write charges are not included. Reasoning models bill their thinking as output tokens.
Head-to-head comparisons
- Claude Opus 5.5 vs Claude Fable 5.1
- Claude Opus 5.5 vs GPT-6 Astra
- Claude Opus 5 vs GPT-6 Astra
- GPT-6.1 Sol vs Claude Opus 5.5
- GPT-6.1 Sol vs GPT-6 Astra
- GPT-6.1 Sol vs GPT-6 Sol
The models
- GPT-6.1 Sol: GPT-6.1 Sol is OpenAI's mid-tier GPT-6 model, at $2 per million input tokens and $10 per million output tokens, one fifth of GPT-6 Astra's price. OpenAI pitches it as close to Astra on coding and professional work, and Artificial Analysis puts it at 51.8 on its Intelligence Index against Astra's 52.7.
- Claude Opus 5.5: Claude Opus 5.5 is Anthropic's current Opus model and the one Anthropic recommends starting with, at $4 per million input tokens and $20 per million output tokens, 20% below Claude Opus 5. It has the highest Artificial Analysis Intelligence Index of the six models we track: 57.6 at max effort.
- GPT-6 Sol: GPT-6 Sol is the original mid-tier GPT-6 model, at $2 per million input tokens and $10 per million output tokens. GPT-6.1 Sol replaced it as OpenAI's recommended Sol one week later at the same prices, but GPT-6 Sol is still on the API and is the faster of the two at max effort.
- GPT-6 Astra: GPT-6 Astra is OpenAI's most capable GPT-6 model, at $10 per million input tokens and $50 per million output tokens, five times GPT-6.1 Sol. OpenAI aims it at the hardest reasoning, coding and research work; on Artificial Analysis it scores 52.7 on the Intelligence Index, a point above GPT-6.1 Sol.
- Claude Fable 5.1: Claude Fable 5.1 is Anthropic's most capable model open to all customers, a tier above Opus, at $10 per million input tokens and $50 per million output tokens. Anthropic advises starting with Claude Opus 5.5 for most work and using Fable 5.1 for demanding reasoning and long-horizon agentic work; on Artificial Analysis, Opus 5.5 currently scores higher.
- Claude Opus 5: Claude Opus 5 is Anthropic's previous Opus model, released in July 2026 at $5 per million input tokens and $25 per million output tokens. Since September 22 it is a legacy model: Claude Opus 5.5 costs less and scores higher on every benchmark both models have a score for, so new projects should start there.
Other workloads
| Model | Document Q&A | Coding agent |
|---|---|---|
| GPT-6.1 Sol | $127 | $187 |
| Claude Opus 5.5 | $254 | $374 |
| GPT-6 Sol | $154 | $214 |
| GPT-6 Astra | $770 | $1,070 |
| Claude Fable 5.1 | $568 | $868 |
| Claude Opus 5 | $385 | $535 |
Document Q&A: 5,000 questions over the same 60,000-token document set (90% cache hits), 800 output tokens each (300M in, 4M out). Coding agent: 200 tasks, each 1.5 million input tokens (90% cache hits) and 50,000 output tokens (300M in, 10M out). Cached input is billed at the cache-read price; cache-write charges are not included.
How we gather and check these numbers: our method.
Sources
- OpenAI API docs: Pricing (checked 2026-10-06)
- Claude docs: Pricing (checked 2026-10-06)