Compare · ModelsLive · 3 picked · head to head

GPT-5.5 vs Claude Mythos Preview 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 5 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
GPT-5.5
#2 by perf·no signal
QUIET
Claude Mythos Preview
#4 by perf·#2 by attention
DESERVED
Gemini 3.1 Pro Preview
#38 by perf·no signal
QUIET
Best value
1.8x better value than GPT-5.5
GPT-5.5
4.9 pts/$
$17.50/M
Claude Mythos Preview
no price
Gemini 3.1 Pro Preview
8.7 pts/$
$7.00/M
Vendor risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
Anthropic logo
Anthropic
$380.0B·Tier 1
Medium risk
Google DeepMind logo
Google DeepMind
$4.00T·Tier 1
Low risk
Head to head
GPT-5.5Claude Mythos PreviewGemini 3.1 Pro Preview
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.
GPT-5.5
93.6
Claude Mythos Preview
94.5
Gemini 3.1 Pro Preview
92.1
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.
GPT-5.5
82.7
Claude Mythos Preview
82.0
Gemini 3.1 Pro Preview
78.4
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.
GPT-5.5
95.0
Gemini 3.1 Pro Preview
98.0
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.
GPT-5.5
78.7
Claude Mythos Preview
79.6
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
BenchmarkGPT-5.5Claude Mythos PreviewGemini 3.1 Pro Preview
GPQA diamond
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
93.694.592.1
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.
82.782.078.4
ARC-AGI
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
95.098.0
OSWorld
OSWorld · tests AI agents on real-world computer tasks across operating systems, including web browsing, file management, and application use.
78.779.6
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
OpenAI logoGPT-5.5$5.00$30.00400K tokens (~200 books)$112.50
Anthropic logoClaude Mythos Preview1.0M tokens (~500 books)
Google DeepMind logoGemini 3.1 Pro Preview$2.00$12.001.0M tokens (~524 books)$45.00