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ModelCap

GPT-5.1-Codex-Max

API only

OpenAI·openai/gpt-5.1-codex-max

GPT-5.1-Codex-Max listed OpenRouter input price is $1.25 per 1M tokens and listed output price is $10.00 per 1M tokens, from OpenRouter listed prices as of 22 Sept 2026, 02:49 UTC.

GPT-5.1-Codex-Max has a published context limit of 400K tokens in the ModelCap catalogue as of 22 Sept 2026, 02:49 UTC.

GPT-5.1-Codex-Max has 1 published OpenRouter serving endpoint, from OpenRouter as of 22 Sept 2026, 02:49 UTC.

GPT-5.1-Codex-Max 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
Not scored · 0% support · score interval not available
Market Gravity
21.2Increased by 0.1
Secondary market signal
Input
$1.25
per 1M tokens
Output
$10.00
per 1M tokens
Context
400K
tokens
Providers
1
endpoint
Gateway spend
latest · Vercel share

Providers

Uptime measured over the last 30 minutes
ProviderInputOutputContextQuantUptime
Azure$1.25$10.00400K

ModelCap Index · Current board

Methodology
Not scored · no public benchmark evidence
Public rank basis
Not scored (abstained)
Index support
0.0% · not applicable
Index interval
Not available
Rank posterior
Not available
Top 5 / Top 10 probability
Not available / Not available
Posterior as of
Snapshot timestamp unavailable
Evidence as of
No admitted evaluation publication timestamp
Identity binding
Exact catalogue product · openai/openai/gpt-5.1-codex-max · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Index observations used
0
Architecture fallback
abstained · 0% coverage · 0 anchors
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
Evidence status
No admitted measured evidence
General preference
Coding
Agents & tools
Reasoning
Evidence breadth
0%
Evidence coverage
0%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
5.7
Liquidity (providers × uptime)
35.8
Open reach (HF downloads)
Surface (context / tools / modalities)
93.3
Freshness
33.0
  • · OpenRouter popularity #232
  • · 1 live provider
  • · Catalogue: context 400000, reasoning, tools, modalities Text/Image
  • · First seen 2025-12-04

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

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.

Experimental capability estimate

Estimate policy
Estimator abstained

insufficient-artifact-metadata

Feature coverage
86%
Training support
209 models · 120 lineages

insufficient-artifact-metadata. This layer predicts from admitted evidence and safe metadata only. It never enters ModelCap Score or rank.

Deployment readiness

Metadata index
30.1
limited · 38% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
80.0
Evaluation provenance
0.0

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.admitted-evaluation-observations, evaluationProvenance.capability-family-breadth, evaluationProvenance.evaluation-source-diversity, evaluationProvenance.identity-and-source-confidence, 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
21.2
OpenRouter weekly popularity
#232 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

No matched Arena rating

This model is visible because it is available in the live catalogue, but it has no trustworthy community result yet. ModelCap does not infer a quality score from price, features, or market activity.

Market Gravity breakdown

Usage55%
5.7

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
35.8

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%
33.0

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

Specification

Context window
400K tokens
Max output
128K tokens
Inputs
Text, Image
Outputs
Text
Tokenizer
GPT
Cached input tokens
$0.125 / 1M
First seen on OpenRouter
4 Dec 2025

Capabilities

  • Supported: Reasoning
  • Supported: Tool use
  • Supported: Structured output
  • Supported: Response format
  • Not supported: Moderated

GPT-5.1-Codex-Max: common questions

How does GPT-5.1-Codex-Max rank among AI models?

GPT-5.1-Codex-Max has no public ModelCap Index position as of 22 September 2026: the snapshot lacks enough matched benchmark evidence, or the identity match is unresolved. Its catalogue facts (price, context, providers) are shown without a rank.

How much does GPT-5.1-Codex-Max cost per 1M tokens?

GPT-5.1-Codex-Max is listed at $1.25 per 1M input tokens and $10.00 per 1M output tokens as of 22 September 2026. 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 $7.50 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-5.1-Codex-Max?

GPT-5.1-Codex-Max has a published context window of 400K tokens (400,000) 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-5.1-Codex-Max 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-5.1-Codex-Max?

One provider serves GPT-5.1-Codex-Max through OpenRouter as of 22 September 2026: Azure. Each provider's price, context limit, quantization and measured uptime are in the providers table above.

When was GPT-5.1-Codex-Max released?

GPT-5.1-Codex-Max first appeared in the catalogue on 4 Dec 2025. It is the current version in its family. Rank and price movements since then are recorded on the site's changes feed.