Automated page. Written and translated automatically by AI and checked against the sources by software; no human editor. SI-IQ is an index built from public benchmark results, not an IQ test. How it works

How smart is Claude Opus 5?

136 SI-IQ · 90% interval 133–140
Rank 11 of 80 ranked models · Plausible rank range 4–16

Claude Opus 5 is a model from Anthropic, released on Jul 24, 2026. Its SI-IQ is 136 (90% interval 133–140), estimated from 8 benchmark results by 2 independent evaluators. Its strongest area is Math and its weakest is Knowledge.

Facts

Developer: Anthropic
Released: Jul 24, 2026
Access: API access
Benchmarks used: 8 results from 2 evaluators
API price: $5.00 input / $25 output per 1M tokens (developer's price list, Oct 18, 2026)
Context window: 1,000,000 tokens

Ability by area (SI-IQ, 90% interval)

Every benchmark result we used

Each score is one value exactly as the source published it: for Epoch AI the best of its run settings, for OpenRouter the median hosting provider (the developer's own hosting when it ran the test). “Implied SI-IQ” is the ability that this single result points to; the overall SI-IQ is their precision-weighted average.

Benchmark	Area	Score	Implied SI-IQ	Evaluated by	As listed by the source	Retrieved	Source
Chess Puzzles	Reasoning	43.0%	129	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
Furniture Assembly not in index	Reasoning	60.8%	—	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
Mystery Game Puzzles	Reasoning	59.0%	142	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
FrontierMath Tier 4	Math	73.2%	137	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
FrontierMath Tiers 1–3	Math	85.6%	137	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
OTIS Mock AIME 2024–2025	Math	98.9%	135	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
GPQA Diamond	Knowledge	93.9%	135	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
GPQA Diamond (OpenRouter run)	Knowledge	89.6%	129	OpenRouter	`anthropic/claude-opus-5-20260723` Anthropic · first-party provider (1 of 5 rows)	Oct 18, 2026	OpenRouter benchmark datasets · data file
SimpleQA Verified	Knowledge	59.9%	139	Epoch AI	`claude-opus-5_max`	Oct 18, 2026	Epoch AI Benchmarking Hub · data file
τ²-bench Airline (OpenRouter run)	Agents	77.3%	133	OpenRouter	`anthropic/claude-opus-5-20260723` Anthropic · first-party provider (1 of 5 rows)	Oct 18, 2026	OpenRouter benchmark datasets · data file

Human preference (Arena)

On the Arena leaderboard, where people vote between two anonymous answers, Claude Opus 5 has a rating of 1,490 (1,485–1,495) from 32,495 votes (published Oct 15, 2026). Human preference is a different measure from benchmark ability and is not part of SI-IQ. Arena (Hugging Face)

Models with similar SI-IQ

Model	SI-IQ
Claude Fable 5Anthropic	138	Claude Opus 5 vs Claude Fable 5
GPT-5.5OpenAI	138	Claude Opus 5 vs GPT-5.5
GPT-5.6 TerraOpenAI	134	Claude Opus 5 vs GPT-5.6 Terra
Claude Fable 5.1Anthropic	140	Claude Opus 5 vs Claude Fable 5.1
GPT-5.6 SolOpenAI	140	Claude Opus 5 vs GPT-5.6 Sol

Computed with SI-IQ method version 1.0.0. Read the full methodology

Data sources: Arena leaderboard dataset on Hugging Face (CC BY 4.0); Epoch AI, ‘Capabilities & benchmarking’ (CC BY 4.0); API list prices via LiteLLM's price table (MIT); each price links to the developer's pricing page; Source: OpenRouter (openrouter.ai), licensed under CC BY 4.0: reuse and republish with attribution to OpenRouter..