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ModelCap

Grok 4.5

Current board #11Arena #35API only

xAI·x-ai/grok-4.5

Grok 4.5 is a language model published by xAI. 4 OpenRouter endpoints are published in the latest snapshot. It accepts text, image, file input and returns text. The published context limit is 500K tokens. The catalogue declares support for reasoning, tool use, structured outputs.

ModelCap Index · Current board
83.6#11
Measured · 89% support · score interval 83.6–89.4
Market Gravity
42.6
Secondary market signal
Input
$2.00
per 1M tokens
Output
$6.00
per 1M tokens
Context
500K
tokens
Providers
4
endpoints
Gateway spend
—
latest · Vercel share

Providers

Uptime measured over the last 30 minutes
ProviderInputOutputContextQuantUptime
xAIzdrCheapest$2.00$6.00500K—99.94%
xAI$2.00$6.00500K—99.91%
xAIzdr/priority$4.00$12.00500K—99.94%
xAIpriority$4.00$12.00500K—99.91%

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
Default
Grok 4.5
5.56%
CI 4.3–6.9%
#141.2M obs
27K sessions
LMArena Agent
Match 100%

Other versions (2)

ModelCap Index · Current board

Methodology
83.6
Measured · 5 public benchmark observations across 5 boards
Current board
#11
Public rank basis
Measured (measured)
Index support
88.9% · strong
Index interval
83.6–89.4
Rank posterior
Not available
Top 5 / Top 10 probability
Not available / Not available
Posterior as of
Snapshot timestamp unavailable
Identity binding
Exact catalogue product · x-ai/x-ai/grok-4.5 · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Direct benchmark observations
5
Breadth-adjusted BES point estimate
86.5
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
86.5
Evidence status
confirmed · 97% mass
General preference
88.1
Coding
90.6
Agents & tools
67.1
Reasoning
60.3
Evidence breadth
100%
Evidence coverage
89%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
39.7
Liquidity (providers × uptime)
35.0
Open reach (HF downloads)
—
Surface (context / tools / modalities)
95.0
Freshness
89.1
  • · OpenRouter popularity #31
  • · 1 live provider
  • · Catalogue: context 500000, reasoning, tools, modalities Text/Image/File
  • · First seen 2026-07-08

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
46.3
partial · 56% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
74.7
Evaluation provenance
88.9

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
42.6
OpenRouter weekly popularity
#31 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
#35 of 385
Rating
1468.4
95% confidence interval
1463–1474
Votes
15K
Source snapshot
6 Aug 2026, 13:00 UTC
Category
overall
Identity match confidence
100%

Market Gravity breakdown

Usage55%
39.7

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
35.0

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%
89.1

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

Specification

Context window
500K tokens
Max output
—
Inputs
Text, Image, File
Outputs
Text
Tokenizer
Grok
Cached input tokens
$0.30 / 1M
First seen on OpenRouter
8 Jul 2026

Capabilities

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