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ModelCap

Claude Opus 5.5

Arena #4No linked weights6.9d #1 → #2

Anthropic·#2 of 352 on the current board

Claude Opus 5.5 is a language model from Anthropic. It ranks #2 of 352 on ModelCap's current board, with an Index score of 86.8, measured on 4 public benchmarks. Its score range of 82.1–91.5 spans positions #1–#7. It is listed at $4.00 per million input tokens and $20.00 per million output tokens across 5 providers. It reads up to 1M tokens of context, with no downloadable weights linked in the current source data.

Figures as of 7 Nov 2026, 13:42 UTC · download the public dataset · methodology

ModelCap Index · Current board
86.8#2
Measured on 4 public benchmarks · range 82.1–91.5
Evidence as of 6 Nov 2026, 19:11 UTC
Market Gravity
71.4Decreased by 1.4
Secondary market signal
Input
$4.00
per 1M tokens
Output
$20.00
per 1M tokens
Context
1M
tokens
Providers
5
11 endpoints
Gateway spend
22.11%
latest · Vercel share

Providers

Uptime measured over the last 30 minutes
ProviderInputOutputContextQuantUptime
Amazon BedrockCheapest$4.00$20.001M—100.0%
Anthropic$4.00$20.001M—100.0%
Azureglobal$4.00$20.001M—100.0%
Claude Platform on AWS$4.00$20.001M—100.0%
Googleglobal$4.00$20.001M—100.0%
Amazon Bedrockeu-west-1$4.40$22.001M—100.0%
Amazon Bedrockus-east-1$4.40$22.001M—100.0%
Azureus$4.40$22.001M——
Googleus$4.40$22.001M——
Googleeurope$4.40$22.001M—100.0%
Anthropicfast$8.00$40.001M—100.0%

Reasoning efforts

Best supported result can inform ModelCap

Published Max, X-High, High and other configurations for this model. These are sourced scores, not head-to-head essays.

EffortAgent scoreSource rankSampleSource
Max
Claude Opus 5.5 (Max)
20.14%
CI 18.1–22.2%
#12.4M obs
14K sessions
LMArena Agent
Match 100%

Related community configurations

Human preference rating
ConfigurationRatingSource rankVotesSource
High
Claude Opus 5.5 (High)
1505
CI 1499–1511
#415KLMArena
Match 100%

Publisher launch results (6)

Publisher’s own claims

Scores Anthropic publishes for this model, with the figures the same tables give for other models. They are the publisher describing its own model, not independent measurement. An independent general board already measures this model, so these claims play no part in its score.

BenchmarkReportedSame table, other models
Terminal-Bench 4.0
66.4
GPT-6 Astra 57.9 · Fable 5.1 55.8 · Opus 5 52.3 · GPT-5.6 Sol 37.3
FrontierCode v1.1
54.4
GPT-6 Astra 53.3 · Fable 5.1 50.3 · Opus 5 48 · GPT-5.6 Sol 47.5
AutomationBench
40
GPT-6 Astra 41.4 · Fable 5.1 31.4 · GPT-5.6 Sol 28.8 · Opus 5 26.9
Humanity’s Last Exam with tools
67.7
“67.7% with tools”
Fable 5.1 65.6 · Opus 5 63.6 · GPT-6 Astra 57.2
Terminal-Bench Science 0.1
58.7
GPT-6 Astra 64.6 · Fable 5.1 52.6 · Opus 5 29 · GPT-5.6 Sol 22.4
OSWorld 2.1 partial
81.8
“81.8% partial”
Fable 5.1 80.7 · Opus 5 74

Other versions (7)

ModelCap Index · Current board

Methodology
86.8
Measured on 4 public benchmarks
Current board
#2 of 352
Score range
82.1–91.5
Rank range
#1–#7
Evidence as of
6 Nov 2026, 19:11 UTC
Benchmarks used
ARC-AGI-2 Verified, Arena Coding, Arena Overall, LMArena Agent
Technical details
Public rank basis
Measured (measured)
Evidence label
Measured · 4 public benchmark observations across 4 boards
Index support
66.4% · strong
Identity binding
Exact catalogue product · anthropic/anthropic/claude-opus-5.5 · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Index observations used
4
Qualified Index evidence point
86.8
Bayesian Evidence Score · measured evidence input only

BES normalizes admitted public benchmark evidence for measured Index rows. Its legacy score and observables prior do not define the public language rank.

Observed capability
86.8
Evidence status
confirmed · 90% mass
General preference
86.7
Coding
85.2
Agents & tools
93.0
Reasoning
86.9
Evidence breadth
100%
Evidence coverage
66%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
66.6
Liquidity (providers × uptime)
92.4
Open reach (HF downloads)
—
Surface (context / tools / modalities)
100.0
Freshness
84.0
  • · OpenRouter popularity #7
  • · 5 live providers
  • · Catalogue: context 1000000, reasoning, tools, modalities Text/Image/File
  • · First seen 2026-09-22

These adoption and deployment observations remain context only. They do not change this model's ModelCap Index score or rank.

BES evidence selected · measured input only

The bounded 0–100 capability score blends each source’s competitive placement with its published achievement, then combines capability families. Evidence breadth adds a modest uncertainty adjustment; price and popularity are not part of benchmark-led rank.

Deployment readiness

Metadata index
53.8
partial · 56% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
100.0
Evaluation provenance
88.5

Not yet published: a pinned repository revision, the architecture and model type, a parameter count, safetensors weight metadata, the base model it derives from, a declared licence, a link to the licence terms, pinned evaluation dataset versions.

A metadata completeness and deployability index—not a safety certification, quality grade, or production-readiness claim.

Market activity

Venue coverage
Market Gravity
71.4
OpenRouter weekly popularity
#7 of 340
Vercel token share · 7d
6.54%
Vercel request share · 7d
2.92%
Venue data through
2026-11-07

Market Gravity uses OpenRouter’s full-catalogue popularity order. Sparse Vercel top-ten observations appear only when published and do not affect the score.

Arena preference

Status
Ranked
Source
LMArena
Official rank
#4 of 419
Rating
1505.1
95% confidence interval
1499–1511
Votes
15K
Source published at
6 Nov 2026, 00:00 UTC
Category
overall
Identity match confidence
100%

Market Gravity breakdown

Usage55%
66.6

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
92.4

Independent providers versus the model's open or closed cohort, weighted by uptime.

Open reach15%
50.0

Hugging Face 30-day downloads for open models; neutral for closed models.

Freshness5%
84.0

Time since first public availability, on a six-month half-life.

Specification

Model ID
anthropic/claude-opus-5.5
Context window
1M tokens
Declared output cap
128K tokens

OpenRouter catalogue or provider-endpoint declaration. Limits can vary by provider and prompt length; a model-wide maximum has not been independently verified. OpenRouter metadata

Inputs
Text, Image, File
Outputs
Text
Tokenizer
Claude
Cached input tokens
$0.20 / 1M
First seen on OpenRouter
22 Sept 2026

Capabilities

  • Supported: Reasoning
  • Supported: Tool use
  • Supported: Structured output
  • Supported: Response format
  • Supported: Moderated

Compare Claude Opus 5.5 with

Pick any model

Benchmark leaderboards featuring Claude Opus 5.5

All leaderboards
Public benchmark boards on which Claude Opus 5.5 has a published result
LeaderboardScoreSource rankConfigurationPublished
Arena text leaderboardArena (LMArena)15051499–1511#4 of 419High6 Nov 2026
Arena coding leaderboardArena (LMArena)15491538–1560#5 of 414High6 Nov 2026
LMArena Agent leaderboardLMArena20.1%18.1%–22.2%#1 of 58Max4 Nov 2026
ARC-AGI-2 leaderboardARC Prize Foundation93.3%#3 of 281High6 Nov 2026
Artificial Analysis Intelligence IndexArtificial Analysis59.1#2 of 99Max5 Nov 2026
Terminal-Bench 4.0 leaderboardTerminal-Bench (Laude Institute)64.9%61.7%–68.0%#1 of 35Claude Code · Max22 Sept 2026

Alternatives to Claude Opus 5.5, by the numbers

Ranked neighbours

Models within 3 places of #2 on the ModelCap Index.

Cheaper at a similar or higher Index

Index score within 3 points of, or above, this model's, with a lower listed blended price (3:1 input:output).

Other ranked Anthropic models

The same publisher's other current models with a public Index position.

Claude Opus 5.5: common questions

How does Claude Opus 5.5 rank among AI models?

Claude Opus 5.5 holds ModelCap Index position #2 of 352 ranked language models as of 7 November 2026, with an Index score of 86.8 (interval 82.1–91.5); evidence: measured. The Index combines public benchmark boards with published uncertainty; the methodology page explains the weighting.

How much does Claude Opus 5.5 cost per 1M tokens?

Claude Opus 5.5 is listed at $4.00 per 1M input tokens and $20.00 per 1M output tokens as of 7 November 2026 across 5 providers. Prices come from the OpenRouter catalogue and re-observe on every refresh. For 1,000 requests using 2,000 input and 500 output tokens each, the listed rates imply $18.00 total (2M input + 0.5M output). This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the chosen endpoint's rate and limits before budgeting.

What is the context window of Claude Opus 5.5?

Claude Opus 5.5 has a published context window of 1M tokens (1,000,000). The snapshot lists a 128,000 token catalogue-declared route output cap. OpenRouter catalogue or provider-endpoint declaration. Limits can vary by provider and prompt length; a model-wide maximum has not been independently verified. The providers table lists each endpoint's context limit.

Is Claude Opus 5.5 open-weight?

No linked weights. No downloadable model weights are linked in the current source data. This does not identify every API or chat product that offers the model.

Which API providers serve Claude Opus 5.5?

5 providers serve Claude Opus 5.5 through OpenRouter as of 7 November 2026: Amazon Bedrock, Azure, Google, Claude Platform on AWS and Anthropic. Each provider's price, context limit, quantization and measured uptime are in the providers table above.

Which benchmarks has Claude Opus 5.5 been evaluated on?

Claude Opus 5.5 has published results on 6 public boards tracked by ModelCap as of 7 November 2026: Arena text 1505 (#4 of 419), Arena coding 1549 (#5 of 414), LMArena Agent 20.1% (#1 of 58), ARC-AGI-2 93.3% (#3 of 281) and AA Intelligence Index 59.1 (#2 of 99) and more. Each board page ranks every tracked model on that benchmark. The ModelCap Index scores the results its methodology admits, with published uncertainty, and shows reference boards without scoring them.

How does Claude Opus 5.5 compare with Gemini 4 Argon?

Claude Opus 5.5 ranks #2 (Index 86.8) and Gemini 4 Argon ranks #1 (Index 87.9) on the ModelCap Index as of 7 November 2026. The head-to-head page lines up their benchmarks, listed prices, context windows and provider counts side by side.

When was Claude Opus 5.5 released?

Claude Opus 5.5 first appeared in the catalogue on 22 Sept 2026. It is the current version in its family. Rank and price movements since then are recorded on the site's changes feed.