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Leaderboard / Anthropic

Claude Opus 5.5

Anthropic Max CLOSED Proprietary
Other settings:High · 99
Verdict

Claude Opus 5.5 is one of the very best models right now: #3 of 406 by SIscope score. Strong at everything it's been tested on, especially coding. On the pricey side: costs more than 89% of priced models.

SIscope score
97
#3 of 406
Human-vote rank
Not on board
Text arena
Price per 1M tokens, blended
$8
$4 in · $20 out
Context window
1M
1,000,000 tokens

Shape

Each spoke is a category, 0 at the centre, 100 at the edge.

CodingAgentsReasoningMathChatno data yetInstructionsno data yet

Category scores

Percentiles: 90 means better than about 90% of tested models.

Coding100
Agents & tools100
Reasoning & knowledge92
Math97
Chat qualityNo data yet–
Following instructionsNo data yet–

What goes into each category · Compare with DeepSeek V4.1 Flash

Coding votes over time

WebDev arena, recent updates.

180018081815Oct 16: 1807.3 (rank #1)Oct 18: 1806.2 (rank #1)Oct 19: 1807.3 (rank #1)Oct 22: 1806.9 (rank #1)Oct 23: 1806.9 (rank #1)Oct 27: 1808.7 (rank #1)Oct 28: 1809.8 (rank #1)Oct 16Oct 28

Independent test runs

Run by Epoch AI on the same harness for every model. Bars show the share of questions answered correctly.

GPQA Diamond91%
PhD-level science multiple choice questions
Better than 87% of 333 tested models. Run Sep 22, 2026.
SimpleQA Verified72%
Short factual questions; rewards not making things up
Better than 96% of 100 tested models. Run Sep 22, 2026.
OTIS Mock AIME 2024-25100%
Competition maths problems in the style of AIME
Better than 96% of 313 tested models. Run Sep 22, 2026.
FrontierMath Tiers 1-391%
Very hard, unpublished research-style maths problems
Better than 98% of 122 tested models. Run Sep 22, 2026.

Human-vote arenas

People compare two anonymous answers and pick the better one. Scores work like chess ratings.

ArenaRankScoreRange (95%)VotesUpdated
Text arena
Everyday chat, blind human votes
Not on this board yet
WebDev arena
Building web apps, blind human votes
#1 of 15218101797–18233,473Oct 28, 2026
Vision arena
Questions about images, blind human votes
Not on this board yet
Agent arena
Real multi-step agent sessions
#1 of 5720.0%17.9–22.1%13,954Nov 2, 2026

Source: Arena (formerly LMArena) leaderboard dataset, CC BY 4.0. Fetched Nov 4, 2026.

Price

Input
$4
per 1M tokens
Output
$20
per 1M tokens
Blended
$8
3 in : 1 out, per 1M
Context window
1M
max tokens per request
Speed
Coming soon
our own tests

List price from the OpenRouter models API (anthropic/claude-opus-5.5), Nov 4, 2026. Providers can charge differently.