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ModelCap

GPT-5.5

Current board #12Arena #28API only

OpenAI·openai/gpt-5.5

GPT-5.5 is ModelCap current-board rank #12 with Index 80.5 (Measured), from the ModelCap Index as of 22 Sept 2026, 02:49 UTC.

GPT-5.5 listed OpenRouter input price is $5.00 per 1M tokens and listed output price is $30.00 per 1M tokens, from OpenRouter listed prices as of 22 Sept 2026, 02:49 UTC.

GPT-5.5 has a published context limit of 1M tokens in the ModelCap catalogue as of 22 Sept 2026, 02:49 UTC.

GPT-5.5 has 7 published OpenRouter serving endpoints, from OpenRouter as of 22 Sept 2026, 02:49 UTC.

GPT-5.5 weight access is api only, from ModelCap classification of published repository metadata as of 22 Sept 2026, 02:49 UTC.

Snapshot facts · download the public dataset · methodology

ModelCap Index · Current board
80.5#12
Measured · 90% support · score interval 74.9–86.1
Evidence as of 21 Sept 2026, 17:21 UTC
Market Gravity
44.2Increased by 0.1
Secondary market signal
Input
$5.00
per 1M tokens
Output
$30.00
per 1M tokens
Context
1M
tokens
Providers
7
endpoints
Gateway spend
latest · Vercel share

Providers

Uptime measured over the last 30 minutes
ProviderInputOutputContextQuantUptime
OpenAIflexCheapest$2.50$15.001M
Azure$5.00$30.001M100.0%
OpenAI$5.00$30.001M100.0%
Azureus$5.50$33.001M
Azureeu$5.50$33.001M
Amazon Bedrockus-east-1$5.50$33.001M
OpenAIfast$12.50$75.001M

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)
5.03%
CI 4.16.0%
#102.5M obs
53K sessions
LMArena Agent
Match 100%
Default
GPT 5.5
2.67%
CI 1.93.5%
#202.1M obs
81K sessions
LMArena Agent
Match 100%

Related community configurations

Human preference rating
ConfigurationRatingSource rankVotesSource
High
gpt-5.5-high
1482
CI 1478–1486
#2065KLMArena
Match 100%
Instant
gpt-5.5-instant
1474
CI 1469–1479
#3226KLMArena
Match 98%

Other versions (6)

ModelCap Index · Current board

Methodology
80.5
Measured · 7 public benchmark observations across 7 boards
Current board
#12
Public rank basis
Measured (measured)
Index support
90.3% · strong
Index interval
74.9–86.1
Rank posterior
Not available
Top 5 / Top 10 probability
Not available / Not available
Posterior as of
Snapshot timestamp unavailable
Evidence as of
21 Sept 2026, 17:21 UTC
Identity binding
Exact catalogue product · openai/openai/gpt-5.5 · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Index observations used
7
Qualified Index evidence point
80.5
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
80.5
Evidence status
confirmed · 97% mass
General preference
82.3
Coding
80.2
Agents & tools
63.5
Reasoning
62.5
Evidence breadth
100%
Evidence coverage
90%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
22.9
Liquidity (providers × uptime)
85.3
Open reach (HF downloads)
Surface (context / tools / modalities)
100.0
Freshness
56.4
  • · OpenRouter popularity #86
  • · 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
54.1
partial · 56% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
100.0
Evaluation provenance
90.0

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
44.2
OpenRouter weekly popularity
#86 of 322

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
#28 of 402
Rating
1476.1
95% confidence interval
1472–1480
Votes
66K
Source published at
13 Sept 2026, 00:00 UTC
Category
overall
Identity match confidence
100%

Market Gravity breakdown

Usage55%
22.9

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
85.3

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%
56.4

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

Specification

Context window
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

Compare GPT-5.5 with

Pick any model

Benchmark leaderboards featuring GPT-5.5

All leaderboards
Public benchmark boards on which GPT-5.5 has a published result
LeaderboardScoreSource rankConfigurationPublished
Arena coding leaderboardArena (LMArena)15201514–1526#30 of 397High13 Sept 2026
LMArena Agent leaderboardLMArena5.0%4.1%–6.0%#10 of 46X-High15 Sept 2026
ARC-AGI-2 leaderboardARC Prize Foundation85.0%#18 of 214X-High21 Sept 2026
ARC-AGI-3 leaderboardARC Prize Foundation0.4%#24 of 39High21 Sept 2026
Artificial Analysis Intelligence IndexArtificial Analysis38.4#45 of 151intelligence-index:v4.3:xhigh19 Sept 2026
τ²-Bench Telecom (Artificial Analysis run)Artificial Analysis93.9%#39 of 436tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="GPT-5.5 (xhigh)":reasoning=true5 Sept 2026
Humanity's Last Exam (Artificial Analysis run)Artificial Analysis45.8%#29 of 615hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="GPT-5.5 (xhigh)":reasoning=true5 Sept 2026
Terminal-Bench 2.1 Terminus 2 leaderboardTerminal-Bench78.0#2 of 5X-High23 Apr 2026
WildClawBench OpenClaw leaderboardWildClawBench58.2#5 of 34Default20 Jul 2026

Alternatives to GPT-5.5, by the numbers

Ranked neighbours

Models within 3 places of #12 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 OpenAI models

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

GPT-5.5: common questions

How does GPT-5.5 rank among AI models?

GPT-5.5 holds ModelCap Index position #12 of 248 ranked language models as of 22 September 2026, with an Index score of 80.5 (interval 74.9–86.1); evidence: measured. The Index combines public benchmark boards with published uncertainty; the methodology page explains the weighting.

How much does GPT-5.5 cost per 1M tokens?

GPT-5.5 is listed at $5.00 per 1M input tokens and $30.00 per 1M output tokens as of 22 September 2026; the lowest output price among 3 providers is $15.00 on OpenAI. 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 $25.00 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 GPT-5.5?

GPT-5.5 has a published context window of 1M tokens (1,050,000) and a maximum output of 128K tokens. Individual providers can serve less than the published maximum; the providers table lists each endpoint's own limit.

Is GPT-5.5 open-weight?

API only. No downloadable model weights are linked in the current source data; access is through a hosted API or product.

Which API providers serve GPT-5.5?

3 providers serve GPT-5.5 through OpenRouter as of 22 September 2026: OpenAI, Azure and Amazon Bedrock. Each provider's price, context limit, quantization and measured uptime are in the providers table above.

Which benchmarks has GPT-5.5 been evaluated on?

GPT-5.5 has published results on 9 public boards tracked by ModelCap as of 22 September 2026: Arena coding 1520 (#30 of 397), LMArena Agent 5.0% (#10 of 46), ARC-AGI-2 85.0% (#18 of 214), ARC-AGI-3 0.4% (#24 of 39) and AA Intelligence Index 38.4 (#45 of 151) and more. Each board page ranks every tracked model on that benchmark; the ModelCap Index combines them with published uncertainty.

How does GPT-5.5 compare with Kimi K3?

GPT-5.5 ranks #12 (Index 80.5) and Kimi K3 ranks #11 (Index 82.2) on the ModelCap Index as of 22 September 2026. The head-to-head page lines up their benchmarks, listed prices, context windows and provider counts side by side.

When was GPT-5.5 released?

GPT-5.5 first appeared in the catalogue on 24 Apr 2026, with a published knowledge cutoff of 2025-12-01. It is the current version in its family. Rank and price movements since then are recorded on the site's changes feed.