Compare · ModelsLive · 3 picked · head to head

Claude Mythos Preview vs Gemini 3.1 Pro Preview vs GPT-5.5

Side by side · benchmarks, pricing, and signals you can act on.

Winner summary

Claude Mythos Preview wins 4 of 6 shared benchmarks. Leads in knowledge · agentic.

Category leads
knowledge·Claude Mythos Previewcoding·GPT-5.5reasoning·Gemini 3.1 Pro Previewagentic·Claude Mythos Preview
Hype vs Reality
Claude Mythos Preview
#5 by perf·no signal
QUIET
Gemini 3.1 Pro Preview
#137 by perf·#6 by attention
DESERVED
GPT-5.5
#2 by perf·#4 by attention
DESERVED
Best value
1.4x better value than GPT-5.5
Claude Mythos Preview
n/a
no price
Gemini 3.1 Pro Preview
6.9 pts/$
$7.00/M
GPT-5.5
4.9 pts/$
$17.50/M
Vendor risk
Anthropic logo
Anthropic
$965.0B·Tier 1
Medium risk
Google DeepMind logo
Google DeepMind
$4.20T·Tier 1
Low risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
Head to head
Claude Mythos PreviewGemini 3.1 Pro PreviewGPT-5.5
GPQA diamond
Claude Mythos Preview leads by +0.9
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
Claude Mythos Preview
94.5
Gemini 3.1 Pro Preview
92.6
GPT-5.5
93.6
Terminal Bench
GPT-5.5 leads by +0.7
Terminal-Bench 2.0 · evaluates AI agents on real terminal-based coding tasks · writing scripts, debugging, running tests, and managing projects entirely through command-line interaction. Tests both code quality and terminal fluency. Claude Opus 4.7 scores 69.4%, demonstrating significant agentic terminal competence.
Claude Mythos Preview
82.0
Gemini 3.1 Pro Preview
80.2
GPT-5.5
82.7
ARC-AGI
Gemini 3.1 Pro Preview leads by +3.0
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
Gemini 3.1 Pro Preview
98.0
GPT-5.5
95.0
HLE
Claude Mythos Preview leads by +13.1
HLE (Humanity's Last Exam) · a reasoning benchmark designed to be the hardest public evaluation of AI. Questions span mathematics, physics, philosophy, and logic · curated to be at or beyond the frontier of human expert capability. Tested with and without tool augmentation. Claude Opus 4.7 scores 46.9% without tools and 54.7% with tools · making it one of the few benchmarks where the top score is below 60%.
Claude Mythos Preview
56.8
Gemini 3.1 Pro Preview
43.7
OSWorld
Claude Mythos Preview leads by +0.9
OSWorld · tests AI agents on real-world computer tasks across operating systems, including web browsing, file management, and application use.
Claude Mythos Preview
79.6
GPT-5.5
78.7
SWE-Bench verified
Claude Mythos Preview leads by +18.3
SWE-bench Verified · 500 human-validated tasks from 12 real Python repositories (Django, Flask, scikit-learn, sympy, and others). Each task requires the model to produce a git patch that resolves a real GitHub issue and passes the test suite. The verified subset eliminates ambiguous tasks from the original SWE-bench. Claude Mythos Preview leads at 93.9%, crossing 90% for the first time in 2026. Opus 4.6 scores 80.8%. The benchmark remains the most-cited evaluation for code-generation capability.
Claude Mythos Preview
93.9
Gemini 3.1 Pro Preview
75.6
Full benchmark table
BenchmarkClaude Mythos PreviewGemini 3.1 Pro PreviewGPT-5.5
GPQA diamond
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
94.592.693.6
Terminal Bench
Terminal-Bench 2.0 · evaluates AI agents on real terminal-based coding tasks · writing scripts, debugging, running tests, and managing projects entirely through command-line interaction. Tests both code quality and terminal fluency. Claude Opus 4.7 scores 69.4%, demonstrating significant agentic terminal competence.
82.080.282.7
ARC-AGI
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
—98.095.0
HLE
HLE (Humanity's Last Exam) · a reasoning benchmark designed to be the hardest public evaluation of AI. Questions span mathematics, physics, philosophy, and logic · curated to be at or beyond the frontier of human expert capability. Tested with and without tool augmentation. Claude Opus 4.7 scores 46.9% without tools and 54.7% with tools · making it one of the few benchmarks where the top score is below 60%.
56.843.7—
OSWorld
OSWorld · tests AI agents on real-world computer tasks across operating systems, including web browsing, file management, and application use.
79.6—78.7
SWE-Bench verified
SWE-bench Verified · 500 human-validated tasks from 12 real Python repositories (Django, Flask, scikit-learn, sympy, and others). Each task requires the model to produce a git patch that resolves a real GitHub issue and passes the test suite. The verified subset eliminates ambiguous tasks from the original SWE-bench. Claude Mythos Preview leads at 93.9%, crossing 90% for the first time in 2026. Opus 4.6 scores 80.8%. The benchmark remains the most-cited evaluation for code-generation capability.
93.975.6—
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
Anthropic logoClaude Mythos Preview——1.0M tokens (~500 books)—
Google DeepMind logoGemini 3.1 Pro Preview$2.00$12.001.0M tokens (~524 books)$45.00
OpenAI logoGPT-5.5$5.00$30.00400K tokens (~200 books)$112.50