Skip to content
Leaderboard / Anthropic

Claude Sonnet 5.5

Anthropic Max CLOSED Proprietary
Other settings:xHigh · 96High
Verdict

Claude Sonnet 5.5 doesn't have enough test coverage for an overall SIscope score yet. Strongest at agents & tools, weaker at reasoning & knowledge. On the pricey side: costs more than 77% of priced models.

SIscope score
No score yet
60% coverage, needs 70%
Human-vote rank
Not on board
Text arena
Price per 1M tokens, blended
$4
$2 in · $10 out
Context window
1M
1,000,000 tokens

Shape

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

Codingno data yetAgentsReasoningMathChatno data yetInstructionsno data yet

Category scores

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

CodingNo data yet–
Agents & tools96
Reasoning & knowledge81
Math95
Chat qualityNo data yet–
Following instructionsNo data yet–

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

Independent test runs

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

GPQA Diamond96%
PhD-level science multiple choice questions
Better than 99% of 333 tested models. Run Sep 29, 2026.
SimpleQA Verified47%
Short factual questions; rewards not making things up
Better than 63% of 100 tested models. Run Sep 29, 2026.
OTIS Mock AIME 2024-25100%
Competition maths problems in the style of AIME
Better than 96% of 313 tested models. Run Sep 29, 2026.
FrontierMath Tiers 1-389%
Very hard, unpublished research-style maths problems
Better than 94% of 122 tested models. Run Sep 29, 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
Not on this board yet
Vision arena
Questions about images, blind human votes
Not on this board yet
Agent arena
Real multi-step agent sessions
#3 of 5714.6%11.8–17.4%8,436Nov 2, 2026

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

Price

Input
$2
per 1M tokens
Output
$10
per 1M tokens
Blended
$4
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-sonnet-5.5), Nov 4, 2026. Providers can charge differently.