Compare · ModelsLive · 3 picked · head to head

Claude Mythos Preview vs Gemini 3.1 Pro Preview vs GPT-5 Chat

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

Winner summary

Claude Mythos Preview wins 4 of 5 shared benchmarks. Leads in knowledge · coding.

Category leads
arena·Gemini 3.1 Pro Previewknowledge·Claude Mythos Previewcoding·Claude Mythos Preview
Hype vs Reality
Claude Mythos Preview
#5 by perf·no signal
QUIET
Gemini 3.1 Pro Preview
#137 by perf·#5 by attention
DESERVED
GPT-5 Chat
#4 by perf·#4 by attention
DESERVED
Best value
2.1x better value than Gemini 3.1 Pro Preview
Claude Mythos Preview
n/a
no price
Gemini 3.1 Pro Preview
6.9 pts/$
$7.00/M
GPT-5 Chat
14.6 pts/$
$5.63/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 Chat
Chatbot Arena Elo · Overall
Gemini 3.1 Pro Preview leads by +60.4
Gemini 3.1 Pro Preview
1487.0
GPT-5 Chat
1426.6
GPQA diamond
Claude Mythos Preview leads by +1.9
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
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
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
Terminal Bench
Claude Mythos Preview leads by +1.8
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
Full benchmark table
BenchmarkClaude Mythos PreviewGemini 3.1 Pro PreviewGPT-5 Chat
Chatbot Arena Elo · Overall
—1487.01426.6
GPQA diamond
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
94.592.6—
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—
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—
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.
82.080.2—
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 Chat$1.25$10.00128K tokens (~64 books)$34.38