Technology

GPT-5.6 Sol vs Claude Opus 5 (2026): Public Challenger vs Anthropic's New Frontier Default

GPT-5.6 Sol vs Claude Opus 5 in 2026: pricing, Sol/Terra/Luna tiers, coding benchmarks, safety claims and when to route work to each model.

2
GPT-5.6 Sol
vs
2
Claude Opus 5
Quick Verdict

Opus 5 arrived with a bigger coding jump than the prior Opus 4.8 baseline had: SWE-bench Verified rose from 88.6% to 96%, a 7.4-point gain at an unchanged price, and Opus 5 more than doubled Opus 4.8's Frontier-Bench v0.1 score while topping every competing model including Fable 5. GPT-5.6 Sol still brings real, differentiated strengths — OpenAI's own Terminal-Bench 2.1 state-of-the-art claim, ExploitBench results competitive with Mythos Preview at roughly a third of the output tokens, and the Sol/Terra/Luna tiering for clean cost routing ($5/$30, $2.50/$15, $1/$6). Neither wins outright: route high-ambition terminal-agent and security workloads to GPT-5.6 Sol, or cost-optimize with Terra/Luna; lean on Claude Opus 5 for the highest available coding ceiling, computer-use execution, and Anthropic's own safety-audit findings around deception resistance. With Opus 5 only days old and GPT-5.6 Sol's independent benchmark replication still arriving, run your own evals before committing either model to production-critical paths.

Detailed Comparison

A side-by-side analysis of key factors to help you make the right choice.

Factor
GPT-5.6 SolRecommended
Claude Opus 5Winner
Availability today
Publicly available since July 9, 2026: full OpenAI API plus ChatGPT Plus/Pro, all three tiers, after US regulatory clearance
Publicly available since July 24, 2026 across the Claude API, Bedrock, Google Cloud, Microsoft Foundry, claude.ai, Claude Code, and Cowork
Coding ceiling
OpenAI claims a Terminal-Bench 2.1 state of the art with max reasoning and ultra subagent mode, independently testable since GA
96% on SWE-bench Verified at launch — a 7.4-point jump over Opus 4.8's 88.6%, the largest single-generation coding gain on this page
Frontier reasoning and computer-use
No published Frontier-Bench or OSWorld 2.0 results; strongest published claims remain terminal-agent and cyber-focused
43.3% on Frontier-Bench v0.1 (more than double Opus 4.8's 18.7%) and 70.6% on OSWorld 2.0, beating Fable 5's best computer-use result at a third of the cost
Cybersecurity capability and safeguards
OpenAI's strongest cyber model yet; competitive with Mythos Preview on ExploitBench using about one-third of the output tokens; cleared after government safety review
Anthropic's own safety audit rates Opus 5 the least likely of its current models to behave deceptively, though no equivalent ExploitBench-style claim is published
Price per million tokens
Sol $5/$30; Terra $2.50/$15; Luna $1/$6, plus explicit cache breakpoints and a 90% cache-read discount; also bundled in ChatGPT Plus $20 / Pro $100
$5/$25 input/output, unchanged from Opus 4.8 despite the capability jump; the new default model on Claude Max
Track record and operating history
Publicly launched July 9, 2026 — over two weeks of broad real-world operating history
Publicly launched July 24, 2026 — the newest frontier model in this comparison, with only days of operating history
Independent validation
Launch evals are OpenAI's own; independent Terminal-Bench and ExploitBench replication has had over two weeks to arrive since GA
Launch evals are Anthropic's own and third-party sites (llm-stats.com, BenchLM.ai); independent replication is only just beginning
Best immediate decision
Pilot Sol on your hardest coding and security evals and cost-route lighter work to Terra/Luna
Re-run your Opus 4.8 evals against Opus 5 before assuming old routing rules still apply, especially for coding-ceiling and computer-use tasks
Total Score2/ 82/ 84 ties
Availability today
GPT-5.6 Sol
Publicly available since July 9, 2026: full OpenAI API plus ChatGPT Plus/Pro, all three tiers, after US regulatory clearance
Claude Opus 5
Publicly available since July 24, 2026 across the Claude API, Bedrock, Google Cloud, Microsoft Foundry, claude.ai, Claude Code, and Cowork
Coding ceiling
GPT-5.6 Sol
OpenAI claims a Terminal-Bench 2.1 state of the art with max reasoning and ultra subagent mode, independently testable since GA
Claude Opus 5
96% on SWE-bench Verified at launch — a 7.4-point jump over Opus 4.8's 88.6%, the largest single-generation coding gain on this page
Frontier reasoning and computer-use
GPT-5.6 Sol
No published Frontier-Bench or OSWorld 2.0 results; strongest published claims remain terminal-agent and cyber-focused
Claude Opus 5
43.3% on Frontier-Bench v0.1 (more than double Opus 4.8's 18.7%) and 70.6% on OSWorld 2.0, beating Fable 5's best computer-use result at a third of the cost
Cybersecurity capability and safeguards
GPT-5.6 Sol
OpenAI's strongest cyber model yet; competitive with Mythos Preview on ExploitBench using about one-third of the output tokens; cleared after government safety review
Claude Opus 5
Anthropic's own safety audit rates Opus 5 the least likely of its current models to behave deceptively, though no equivalent ExploitBench-style claim is published
Price per million tokens
GPT-5.6 Sol
Sol $5/$30; Terra $2.50/$15; Luna $1/$6, plus explicit cache breakpoints and a 90% cache-read discount; also bundled in ChatGPT Plus $20 / Pro $100
Claude Opus 5
$5/$25 input/output, unchanged from Opus 4.8 despite the capability jump; the new default model on Claude Max
Track record and operating history
GPT-5.6 Sol
Publicly launched July 9, 2026 — over two weeks of broad real-world operating history
Claude Opus 5
Publicly launched July 24, 2026 — the newest frontier model in this comparison, with only days of operating history
Independent validation
GPT-5.6 Sol
Launch evals are OpenAI's own; independent Terminal-Bench and ExploitBench replication has had over two weeks to arrive since GA
Claude Opus 5
Launch evals are Anthropic's own and third-party sites (llm-stats.com, BenchLM.ai); independent replication is only just beginning
Best immediate decision
GPT-5.6 Sol
Pilot Sol on your hardest coding and security evals and cost-route lighter work to Terra/Luna
Claude Opus 5
Re-run your Opus 4.8 evals against Opus 5 before assuming old routing rules still apply, especially for coding-ceiling and computer-use tasks

Key Statistics

Real data from verified industry sources to support your decision.

OpenAI publicly launched GPT-5.6 Sol, Terra and Luna on July 9, 2026, after the US Department of Commerce cleared a broad release that had been gated since the June 26 preview.

CNBC

GPT-5.6 is priced at $5/$30 per 1M input/output tokens for Sol, $2.50/$15 for Terra and $1/$6 for Luna, with explicit cache breakpoints and a 30-minute minimum cache life.

OpenAI

OpenAI says GPT-5.6 Sol sets a new state of the art on Terminal-Bench 2.1 and is competitive with Mythos Preview on ExploitBench while using about one-third of the output tokens.

OpenAI

Claude Opus 5 launched July 24, 2026 at $5/$25 per million input/output tokens, unchanged from Opus 4.8, positioned as the new default model on Claude Max and the strongest model available on Claude Pro.

Anthropic

Claude Opus 5 leads the SWE-bench Verified leaderboard at 96%, a 7.4-point jump over Opus 4.8's 88.6%, ahead of Claude Mythos 5 (95.5%) and Claude Fable 5 (95%).

BenchLM.ai

Opus 5 scores 70.6% on OSWorld 2.0 and 62.0% on GDPval-AA while keeping Opus 4.8's identical $5/$25 price and 1M-token input / 128K-token output context window.

llm-stats.com

All statistics come from verified third-party sources. Source, year, and direct link are shown on each metric.

When to Choose Each Option

Clear guidance based on your specific situation and needs.

Choose GPT-5.6 Sol when...

  • Your workload is command-line coding, vulnerability research or long-horizon agent work where OpenAI's Terminal-Bench 2.1 and ExploitBench claims could pay off
  • You want the Sol/Terra/Luna tiering to route by cost: Sol for the hardest tasks, Terra and Luna for cheaper high-volume work
  • You already live in the ChatGPT/Codex ecosystem and want GPT-5.6 inside ChatGPT Plus/Pro plus full API access
  • You want a model with over two weeks of independent, real-world operating history rather than a days-old launch

Choose Claude Opus 5 when...

  • You need the highest available coding ceiling — Opus 5's 96% SWE-bench Verified score is a 7.4-point jump over Opus 4.8 at the same price
  • Your workload involves computer-use or frontier reasoning tasks, where Opus 5 posts new highs on OSWorld 2.0 and Frontier-Bench v0.1
  • You're already on Claude Max and want Anthropic's new default model without switching providers
  • You prefer Anthropic's stable, unchanging published rate card ($5/$25) even as the underlying model's capability jumps

Our Recommendation

Opus 5 arrived with a bigger coding jump than the prior Opus 4.8 baseline had: SWE-bench Verified rose from 88.6% to 96%, a 7.4-point gain at an unchanged price, and Opus 5 more than doubled Opus 4.8's Frontier-Bench v0.1 score while topping every competing model including Fable 5. GPT-5.6 Sol still brings real, differentiated strengths — OpenAI's own Terminal-Bench 2.1 state-of-the-art claim, ExploitBench results competitive with Mythos Preview at roughly a third of the output tokens, and the Sol/Terra/Luna tiering for clean cost routing ($5/$30, $2.50/$15, $1/$6). Neither wins outright: route high-ambition terminal-agent and security workloads to GPT-5.6 Sol, or cost-optimize with Terra/Luna; lean on Claude Opus 5 for the highest available coding ceiling, computer-use execution, and Anthropic's own safety-audit findings around deception resistance. With Opus 5 only days old and GPT-5.6 Sol's independent benchmark replication still arriving, run your own evals before committing either model to production-critical paths.

Frequently Asked Questions

Common questions about this comparison answered.

Yes. After a US government-coordinated review, OpenAI publicly launched GPT-5.6 Sol, Terra and Luna on July 9, 2026. All three tiers are available through the OpenAI API, and the models are included in ChatGPT Plus ($20/mo) and Pro ($100/mo) with usage limits.
No. Anthropic replaced Opus 4.8 with Claude Opus 5 on July 24, 2026, at the same $5/$25 price. Opus 5 more than doubled Opus 4.8's Frontier-Bench v0.1 score and jumped SWE-bench Verified from 88.6% to 96%, becoming the new default model on Claude Max.
Claude Opus 5 has the higher published coding ceiling: 96% on SWE-bench Verified versus GPT-5.6 Sol's Terminal-Bench 2.1 state-of-the-art claim on a different benchmark. Sol remains the more terminal-agent and security-focused bet. Run both on your own repos before committing either.
At the top tier they're close: GPT-5.6 Sol is $5/$30 per 1M input/output tokens versus Opus 5's $5/$25 — Opus 5 is actually cheaper on output. But Terra ($2.50/$15) and Luna ($1/$6) make the GPT-5.6 family cheaper overall for high-volume or lighter work, and both models are also bundled into subscription tiers.

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