Compare · ModelsLive · 3 picked · head to head

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

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

Winner summary

Claude Mythos Preview wins 3 of 4 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
#4 by perf·#2 by attention
DESERVED
GPT-5 Chat
#3 by perf·#1 by attention
DESERVED
Gemini 3.1 Pro Preview
#38 by perf·no signal
QUIET
Best value
1.7x better value than Gemini 3.1 Pro Preview
Claude Mythos Preview
no price
GPT-5 Chat
14.6 pts/$
$5.63/M
Gemini 3.1 Pro Preview
8.7 pts/$
$7.00/M
Vendor risk
Anthropic logo
Anthropic
$380.0B·Tier 1
Medium risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
Google DeepMind logo
Google DeepMind
$4.00T·Tier 1
Low risk
Head to head
Claude Mythos PreviewGPT-5 ChatGemini 3.1 Pro Preview
Chatbot Arena Elo · Overall
Gemini 3.1 Pro Preview leads by +66.6
GPT-5 Chat
1426.0
Gemini 3.1 Pro Preview
1492.6
GPQA diamond
Claude Mythos Preview leads by +2.4
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
92.1
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 +3.6
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
78.4
Full benchmark table
BenchmarkClaude Mythos PreviewGPT-5 ChatGemini 3.1 Pro Preview
Chatbot Arena Elo · Overall
1426.01492.6
GPQA diamond
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
94.592.1
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.
82.078.4
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
Anthropic logoClaude Mythos Preview1.0M tokens (~500 books)
OpenAI logoGPT-5 Chat$1.25$10.00128K tokens (~64 books)$34.38
Google DeepMind logoGemini 3.1 Pro Preview$2.00$12.001.0M tokens (~524 books)$45.00