The best AI model right now is Claude Opus 5.5, released September 22, 2026. Anthropic's launch table puts it at 89.9% on SWE-bench Pro and 81.8% on OSWorld 2.1, and it costs $4/$20 per million tokens. It is not first on every benchmark: GPT-6 Astra leads on frontier maths and computer use, and Claude Fable 5.1 on some research tests, both at $10/$50. For most people, though, 'best' means best value, and that is Claude Sonnet 5.5 — near Opus 5.5 on scoped work at half the price.
The safest this comparison default, the cheaper option worth trying first, and the specialist pick — before you read the detail below.
Claude Opus 5.5 is the strongest answer here for this comparison — pick it when quality of output matters more than the $4.00/1M/1M input you pay for it.
Claude Sonnet 5.5 handles the same job for about 50% less per token. Start here and only move up if the output is not good enough.
GPT-6 Astra is the fastest of these for this comparison — worth it when latency is what the reader notices, not the last few points of reasoning depth.
Claude Opus 5.5 is the best overall model as of October 2026, and cheaper than the $10/$50 frontier tier.
GPT-6 Astra and Claude Fable 5.1 still lead specific benchmarks — computer use, frontier maths, some research tests.
For most people the best value is Claude Sonnet 5.5 or GPT-6.1 Sol at $2/$10.
Choose Claude Opus 5.5 when you want the strongest broad model without paying frontier prices.
Choose GPT-6 Astra when your work is computer use, browser agents or frontier maths.
Choose Claude Sonnet 5.5 if price and speed matter as much as peak capability — it is the better daily default.
Switch the scoring lens to see whether the this comparison answer changes when cost, speed, or long-document depth leads the decision.
Anthropic / Balanced / Oct 10, 2026
Near-Opus 5.5 quality on scoped work at half the price.
Ranks models by the broadest mix of coding, writing, research, and long-context usefulness.
The work is long, ambiguous and multi-step — Anthropic positions Opus 5.5 for exactly that — or you need the lowest possible price, where Haiku 5.5 costs a twentieth as much.
Where the this comparison recommendation shifts once you weigh price or latency differently.
Anthropic's new coding default — top SWE-bench Pro score at a lower price than Opus 5.
OpenAI's frontier answer to Fable 5.1 — computer-use and agentic-coding leader at $10/$50.
New frontier leader — better than Fable 5 on every published benchmark, and cheaper to run.
Near-Opus 5.5 quality on scoped work at half the price.
Near-Astra capability at Sol pricing — OpenAI's value pick.
List prices and published scores — the numbers this page's pick is built from.
| Model | Input | Output | Est. month | Context | Speed | Coding | Writing | Research |
|---|---|---|---|---|---|---|---|---|
| Claude Opus 5.5Anthropic | $4.00/1M | $20.00/1M | $80 | 1M tokens | Deliberate | 100 | 97 | 99 |
| GPT-6 AstraOpenAI | $10.00/1M | $50.00/1M | $200 | 1.1M tokens | Deliberate | 100 | 97 | 100 |
| Claude Fable 5.1Anthropic | $10.00/1M | $50.00/1M | $200 | 1M tokens | Deliberate | 100 | 98 | 100 |
| Claude Sonnet 5.5Anthropic | $2.00/1M | $10.00/1M | $40 | 1M tokens | Fast | 98 | 98 | 95 |
Scores out of 100 — how we evaluate models. “Est. month” is 10M in / 2M out at list price: a ceiling, no discounts.
Why each one is on the shortlist for this comparison, what it is genuinely good at, and where we would steer you away from it.
Our pick for this comparison. It scores 100/100 on the coding axis we weight this page by, and nothing else in this shortlist matches it on output quality.
Anthropic's September 22, 2026 Opus — a step up from Opus 5 on agentic coding, long-running agent work and vision, at a lower $4/$20 list price and with fewer tokens spent per finished task.
Your tasks are well-scoped and latency-sensitive — Sonnet 5.5 is half the price and Anthropic says it is the fastest Sonnet yet.
The new premium coding default from Anthropic. Opus 5.5 posts the highest SWE-bench Pro figure in any launch table we track and costs less than Opus 5 did. Fable 5.1 still makes sense for the hardest open-ended research at $10/$50; for almost everything else Opus 5.5 is the better buy, and Sonnet 5.5 at half the price is close behind on well-scoped work.
Full pricing, benchmark table and release notes on the Claude Opus 5.5 page.
Here for latency: it answers fastest of anything listed for this comparison, at 100/100 on coding.
OpenAI's September 3, 2026 frontier release — the first GPT-6 model and OpenAI's answer to Claude Fable 5.1 two days earlier. State of the art on computer use (OSWorld 2.0 72.6% in ~47% less time than GPT-5.6 Sol), agentic coding (Terminal-Bench 4.0 57.9%), and frontier math (FrontierMath Tier 4 97.6%). $10/$50 per 1M tokens, 1.05M context, 128K output, knowledge cutoff April 30, 2026.
You are cost-sensitive or latency-bound — GPT-5.6 Sol is a fifth of the price — or you need it today in an Enterprise workspace, where it is off by default, or for offensive-security work, which it refuses outside OpenAI Daybreak.
The new computer-use and agentic-coding ceiling, and OpenAI's first model priced like a Mythos-class Claude. Astra beats Claude Fable 5.1 on Terminal-Bench 4.0 (57.9% vs 55.8%), Terminal-Bench Science (64.6% vs 52.6%) and FrontierMath Tier 4 (97.6% vs 87.8%), and it is the only model with a credible OSWorld 2.0 result above 70%. It loses to Fable 5.1 on Humanity's Last Exam and on Artificial Analysis's index, costs five times GPT-5.6 Sol, and ships without a SWE-bench number. If your work is computer use, browser agents or math, it is the pick; for everyday coding at scale, Sol at $2/$10 remains the value default.
Full pricing, benchmark table and release notes on the GPT-6 Astra page.
Rounds out the shortlist for this comparison at 100/100 on coding.
New frontier leader — better than Fable 5 on every published benchmark, and cheaper to run. Full Claude Fable 5.1 review →
The value option for this comparison: about 50% less per token than Claude Opus 5.5, at 98/100 on coding. Worth starting here and moving up only if the output disappoints.
Near-Opus 5.5 quality on scoped work at half the price. Full Claude Sonnet 5.5 review →
UseRightAI recommendations are based on practical decision factors people actually feel in day-to-day use.
Newsletter
We email when the this comparison pick changes, when one of these models moves on price, or when something new displaces the current leader.
No spam. Useful updates only. Affiliate disclosures always clearly labeled.
Claude Opus 5.5, as of October 2026. Anthropic reports 89.9% on SWE-bench Pro, 81.8% on OSWorld 2.1 and 67.7% on Humanity's Last Exam, at $4/$20 per million tokens.
On some things. Astra leads on frontier maths (97.6% FrontierMath Tier 4) and computer use (72.6% OSWorld 2.0) in OpenAI's table. On Terminal-Bench 4.0, Opus 5.5 is ahead (66.4% vs 57.9%, both vendor figures), and Astra costs two and a half times as much.
Claude Sonnet 5.5. It holds tone and structure across long drafts, and Anthropic built it for polished documents. Opus 5.5 is the step up for long, high-stakes pieces.
For the hardest open-ended questions, Claude Fable 5.1 or GPT-6 Astra. For most document research, Claude Opus 5.5 or GPT-6.1 Sol, both with windows of about a million tokens.
No. The best model is worth it only when quality failures are expensive enough to justify paying more. For routine work, Claude Haiku 5.5 or GPT-6 Luna at $0.10 per million input tokens is usually the better decision.