Your tasks are well-scoped and latency-sensitive — Sonnet 5.5 is half the price and Anthropic says it is the fastest Sonnet yet.
Strengths
OSWorld 2.0 72.6% vs 65.7% for GPT-5.6 Sol, in roughly 47% less time per task — the new computer-use ceiling
Terminal-Bench 4.0 57.9% — ahead of Claude Fable 5.1 (55.8%), Opus 5 (52.3%) and GPT-5.6 Sol (37.3%)
FrontierMath Tier 4 (v2) 97.6% vs Fable 5.1's 87.8%; Terminal-Bench Science 64.6% vs 52.6%; GPQA Diamond 96.0%
1.05M context with 96.3% on OpenAI MRCR 8-needle at 512K–1M (Sol: 73.8%) and 128K max output
OpenAI's lowest misaligned-outcome rates to date: 2.4% on its computer-use safety benchmark vs 22.0% for Sol, 0% scope-creep on impossible cyber tasks vs 48%
Weaknesses
$10/$50 per 1M — five times GPT-5.6 Sol's $2/$10 and the same premium as Claude Fable 5.1; Fast mode doubles it again
Trails Claude Fable 5.1 on Humanity's Last Exam with tools (57.2% vs 65.0%) and on the Artificial Analysis Intelligence Index (61.2 vs 65.7)
OpenAI published no SWE-bench Verified or SWE-bench Pro figure at launch, so it does not appear on our SWE-bench leaderboard
Rolling out over days, not instantly: Enterprise access is off by default, advanced cyber tasks are refused outside OpenAI Daybreak, and the safety layer can pause or stop legitimate agent runs
OpenAI's own system card finds its written reasoning harder to monitor than Sol's
Ranked alternatives
Strong backups depending on your budget, workload, and preferred tradeoffs.
AnthropicPremium
Claude Opus 5.5
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.
Verdict
Anthropic's new coding default — top SWE-bench Pro score at a lower price than Opus 5.
Quality score
98%
Pricing
$4.00/1M in
$20.00/1M out
Speed
Deliberate
2/5 speed
Context
1M tokens
Released September 22, 2026. Gateway id anthropic/claude-opus-5.5. $4/$20 per 1M (cache read $0.20, cache write $5); Fast mode $8/$40. 1,000,000 context, 128,000 max output, knowledge cutoff June 2026, effort levels low to max. Launch figures as reported by Anthropic: SWE-bench Pro 89.9 (Fable 5.1 81.2, Opus 5 79.2); SWE-bench Multilingual 93.9; Terminal-Bench 4.0 66.4 (xhigh); OSWorld 2.1 81.8; Humanity's Last Exam 67.7; Toolathlon Verified 77.8 (Opus 5 80.6). Verified October 10, 2026.
CodingAgenticFlagship1M contextPremiumNew
Best for
Agentic coding, long-running agents and knowledge work where Opus 5 was the bar
Anthropic's newest Opus flagship — 69.2% SWE-Bench Pro, 88.6% SWE-Bench Verified, 1890 Arena Elo (121 pts ahead of GPT-5.5), and native parallel subagents. Same $5/$25 price as Opus 4.7.
Verdict
Best value premium coder — frontier-grade at half of Fable 5's price.
Quality score
97%
Pricing
$5.00/1M in
$25.00/1M out
Speed
Deliberate
2/5 speed
Context
1M tokens
Launched May 27, 2026. Available on Claude API, AWS Bedrock, Google Vertex AI, Microsoft Foundry, and GitHub Copilot. Fast mode available at $10/$50 per 1M tokens.
Coding leaderSWE-bench Pro #1Parallel subagentsAgenticLong contextPremiumNew
Best for
Hardest coding tasks, parallel agentic workflows, and high-fidelity vision
Anthropic's flagship-tier Opus that comes close to Claude Fable 5's frontier intelligence at half the price — the new default for complex agentic coding and enterprise agents.
Verdict
Best premium model for agentic coding — near-Fable 5 quality at half the price.
Quality score
97%
Pricing
$5.00/1M in
$25.00/1M out
Speed
Deliberate
2/5 speed
Context
1M tokens
Released July 24, 2026 at Opus 4.8's exact pricing. 1M context at standard rates, 128K max output. Anthropic's alignment audit calls it their most aligned model to date. Default model on Claude Max plans.
CodingAgenticFlagship1M contextPremium
Best for
Complex agentic coding and enterprise agent workflows
Anthropic's new Mythos-class flagship and the most capable coding model anyone can use — 80.3% SWE-Bench Pro, an 11-point jump over Opus 4.8. 1M context, 128K output, native parallel subagents. Released June 9, 2026.
Verdict
New global #1 — 80.3% SWE-Bench Pro, the most capable model generally available.
Quality score
98%
Pricing
$10.00/1M in
$50.00/1M out
Speed
Deliberate
2/5 speed
Context
1M tokens
Launched June 9, 2026 as the public, Mythos-class release. Available on the Claude API, Microsoft Foundry, and Google Vertex AI. Free for all users until June 22, 2026. Same underlying model as Claude Mythos 5, with safeguards that block specific high-risk cyber responses.
Coding leaderSWE-Bench Pro #1Mythos-classParallel subagentsAgenticLong contextPremiumNew
Best for
The hardest coding tasks, autonomous multi-step agents, and frontier-grade reasoning
The default answer for coding — 100/100 on the coding axis, and the model we would start with unless the price below rules it out.
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.
Input
$10.00/1M
Output
$50.00/1M
Context
1.1M tokens
Speed
Deliberate
What people actually use it for
Computer-use agents that fill forms, update CRMs, run QA in a browser — 72.6% on OSWorld 2.0 at ~40 minutes per task vs Sol's 75
Agentic coding in Codex with cross-context notes — 57.9% Terminal-Bench 4.0, ahead of Claude Fable 5.1 (55.8%)
Frontier math and science — 97.6% FrontierMath Tier 4 and 64.6% Terminal-Bench Science, both well clear of every rival OpenAI tested
Where it wins
OSWorld 2.0 72.6% vs 65.7% for GPT-5.6 Sol, in roughly 47% less time per task — the new computer-use ceiling
Terminal-Bench 4.0 57.9% — ahead of Claude Fable 5.1 (55.8%), Opus 5 (52.3%) and GPT-5.6 Sol (37.3%)
FrontierMath Tier 4 (v2) 97.6% vs Fable 5.1's 87.8%; Terminal-Bench Science 64.6% vs 52.6%; GPQA Diamond 96.0%
1.05M context with 96.3% on OpenAI MRCR 8-needle at 512K–1M (Sol: 73.8%) and 128K max output
OpenAI's lowest misaligned-outcome rates to date: 2.4% on its computer-use safety benchmark vs 22.0% for Sol, 0% scope-creep on impossible cyber tasks vs 48%
Where it falls down
$10/$50 per 1M — five times GPT-5.6 Sol's $2/$10 and the same premium as Claude Fable 5.1; Fast mode doubles it again
Trails Claude Fable 5.1 on Humanity's Last Exam with tools (57.2% vs 65.0%) and on the Artificial Analysis Intelligence Index (61.2 vs 65.7)
OpenAI published no SWE-bench Verified or SWE-bench Pro figure at launch, so it does not appear on our SWE-bench leaderboard
Rolling out over days, not instantly: Enterprise access is off by default, advanced cyber tasks are refused outside OpenAI Daybreak, and the safety layer can pause or stop legitimate agent runs
OpenAI's own system card finds its written reasoning harder to monitor than Sol's
Skip it if
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.
Our verdict
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.
The value option for coding: about 60% less per token than GPT-6 Astra, at 100/100 on coding. Worth starting here and moving up only if the output disappoints.
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.
Input
$4.00/1M
Output
$20.00/1M
Context
1M tokens
Speed
Deliberate
What people actually use it for
Repository-scale changes and PR work — Anthropic reports 89.9% on SWE-bench Pro, up from 79.2% for Opus 5
Long unattended agent runs where per-task token spend matters as much as the per-token price
Reports, analysis and briefs that need to state findings and next steps plainly
Where it wins
SWE-bench Pro 89.9% in Anthropic's launch table, ahead of Claude Fable 5.1 (81.2%) and Opus 5 (79.2%)
Cheaper than the model it replaces: $4/$20 per 1M against Opus 5's $5/$25, and cache reads at $0.20/1M
1M context and 128K output at standard rates, with effort levels up to max
Where it falls down
Not ahead everywhere: Anthropic's own table has Opus 5 higher on Toolathlon Verified (80.6% vs 77.8%)
Fast mode doubles the price to $8/$40
Terminal-Bench 4.0 differs by effort setting (66.4% at xhigh, 64.8% at max), so single-digit gaps against rivals are directional
Skip it if
Your tasks are well-scoped and latency-sensitive — Sonnet 5.5 is half the price and Anthropic says it is the fastest Sonnet yet.
Our verdict
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.
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FAQ
What is the best AI for coding?
For coding, GPT-6 Astra (OpenAI) is our pick. OpenAI's frontier answer to Fable 5.1 — computer-use and agentic-coding leader at $10/$50. It costs $10/1M input and $50/1M output tokens, with a 1.05M-token context window — enough headroom for all but the largest coding jobs. Claude Opus 5.5 is the closest alternative if it doesn't fit your setup.
Why GPT-6 Astra for coding?
Because the work it is built for overlaps closely with coding: computer-use agents that fill forms, update CRMs, run QA in a browser — 72.6% on OSWorld 2.0 at ~40 minutes per task vs Sol's 75 and agentic coding in Codex with cross-context notes — 57.9% Terminal-Bench 4.0, ahead of Claude Fable 5.1 (55.8%). 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.
What does it cost to use GPT-6 Astra for coding?
On a moderate month — 10M input and 2M output tokens — GPT-6 Astra runs about $200.00 at list price, with no batch or caching discounts applied, so treat that as a ceiling. Claude Opus 5.5 is the cheaper route at roughly $80.00 for the same volume, if coding is high-volume enough for price to lead the decision.
When is GPT-6 Astra the wrong choice for coding?
$10/$50 per 1M — five times GPT-5.6 Sol's $2/$10 and the same premium as Claude Fable 5.1; Fast mode doubles it again. Trails Claude Fable 5.1 on Humanity's Last Exam with tools (57.2% vs 65.0%) and on the Artificial Analysis Intelligence Index (61.2 vs 65.7). Avoid it if 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. None of that rules it out for coding on its own — but if one of those limits maps onto how you actually work, take the alternative on this page seriously rather than defaulting to the top pick.
Is there a cheaper AI that still handles coding?
Claude Opus 5.5 at $4/1M input is the budget option here. Anthropic's new coding default — top SWE-bench Pro score at a lower price than Opus 5. Expect a quality step down on the hardest cases — the usual pattern is to route routine coding volume to Claude Opus 5.5 and keep GPT-6 Astra for the work where a wrong answer is expensive.