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ModelCap

GPT-5.5

Current board #6Arena #20API only

OpenAI·openai/gpt-5.5

GPT-5.5 is a language model published by OpenAI. 6 OpenRouter endpoints are published in the latest snapshot. It accepts file, image, text input and returns text. The published context limit is 1.1M tokens. The catalogue declares support for reasoning, tool use, structured outputs.

ModelCap Index · Current board
87.4#6
Measured · 90% support · score interval 87.4–93.0
Market Gravity
46.7
Secondary market signal
Input
$5.00
per 1M tokens
Output
$30.00
per 1M tokens
Context
1.1M
tokens
Providers
6
endpoints
Gateway spend
—
latest · Vercel share

Providers

Uptime measured over the last 30 minutes
ProviderInputOutputContextQuantUptime
OpenAIflexCheapest$2.50$15.001.1M—35.03%
OpenAI$5.00$30.001.1M—35.03%
Azure$5.00$30.001.1M—100.0%
Azureeu$5.50$33.001.1M——
Amazon Bedrockus-east-1$5.50$33.001.1M——
OpenAIpriority$12.50$75.001.1M—35.03%

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
X-High
GPT 5.5 (xHigh)
8.47%
CI 7.5–9.5%
#71.9M obs
46K sessions
LMArena Agent
Match 100%
High
GPT 5.5 (High)
7.54%
CI 6.6–8.5%
#92.1M obs
71K sessions
LMArena Agent
Match 100%
Default
GPT 5.5
5.44%
CI 4.6–6.3%
#151.6M obs
72K sessions
LMArena Agent
Match 100%

Related community configurations

Human preference rating
ConfigurationRatingSource rankVotesSource
High
gpt-5.5-high
1482
CI 1478–1486
#1752KArena
Match 100%

Other versions (6)

ModelCap Index · Current board

Methodology
87.4
Measured · 5 public benchmark observations across 5 boards
Current board
#6
Public rank basis
Measured (measured)
Index support
90.3% · strong
Index interval
87.4–93.0
Rank posterior
Not available
Top 5 / Top 10 probability
Not available / Not available
Posterior as of
Snapshot timestamp unavailable
Identity binding
Exact catalogue product · openai/openai/gpt-5.5 · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Direct benchmark observations
5
Breadth-adjusted BES point estimate
90.2
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
90.2
Evidence status
confirmed · 97% mass
General preference
91.3
Coding
90.1
Agents & tools
80.1
Reasoning
79.7
Evidence breadth
100%
Evidence coverage
90%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
31.3
Liquidity (providers × uptime)
74.3
Open reach (HF downloads)
—
Surface (context / tools / modalities)
100.0
Freshness
67.0
  • · OpenRouter popularity #50
  • · 3 live providers
  • · Catalogue: context 1050000, reasoning, tools, modalities File/Image/Text
  • · First seen 2026-04-24

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
52.1
partial · 56% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
93.5
Evaluation provenance
89.9

Missing: artifactReproducibility.revision-sha, artifactReproducibility.architecture-and-model-type, artifactReproducibility.parameter-count, artifactReproducibility.serialized-weight-format, artifactReproducibility.base-lineage, accessLegalClarity.declared-license, accessLegalClarity.resolvable-license-terms, evaluationProvenance.evaluation-dataset-revisions.

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

Market activity

Venue coverage
Market Gravity
46.7
OpenRouter weekly popularity
#50 of 298

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
Arena
Official rank
#20 of 385
Rating
1476.7
95% confidence interval
1473–1481
Votes
53K
Source snapshot
6 Aug 2026, 13:00 UTC
Category
overall
Identity match confidence
100%

Market Gravity breakdown

Usage55%
31.3

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
74.3

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%
67.0

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

Specification

Context window
1.1M tokens
Max output
128K tokens
Inputs
File, Image, Text
Outputs
Text
Tokenizer
GPT
Cached input tokens
$0.50 / 1M
First seen on OpenRouter
24 Apr 2026
Knowledge cutoff
2025-12-01

Capabilities

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