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ModelCap

Grok 4.5

All-versions archive #41Arena #42API only

xAI·x-ai/grok-4.5

Grok 4.5 is ModelCap archive rank #41 (Measured), from the ModelCap Index as of 22 Sept 2026, 02:49 UTC.

Grok 4.5 listed OpenRouter input price is $2.00 per 1M tokens and listed output price is $6.00 per 1M tokens, from OpenRouter listed prices as of 22 Sept 2026, 02:49 UTC.

Grok 4.5 has a published context limit of 500K tokens in the ModelCap catalogue as of 22 Sept 2026, 02:49 UTC.

Grok 4.5 has 4 published OpenRouter serving endpoints, from OpenRouter as of 22 Sept 2026, 02:49 UTC.

Grok 4.5 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 · All-versions archive
76.9#41
Measured · 90% support · score interval 71.3–82.5
Evidence as of 21 Sept 2026, 17:21 UTC
Market Gravity
48.9Increased by 0.8
Secondary market signal

Superseded by Grok 4.7. It no longer holds a current-board position; its all-versions archive rank is #41.

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$6.00500K99.13%
xAI$2.00$6.00500K99.33%
xAIzdr/priority$4.00$12.00500K
xAIpriority$4.00$12.00500K

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
2.92%
CI 1.93.9%
#191.9M obs
38K sessions
LMArena Agent
Match 100%

Other versions (4)

ModelCap Index · All-versions archive

Methodology
76.9
Measured · 7 public benchmark observations across 7 boards
All-versions archive
#41
Public rank basis
Measured (measured)
Index support
90.0% · strong
Index interval
71.3–82.5
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 · x-ai/x-ai/grok-4.5 · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Index observations used
7
Qualified Index evidence point
76.9
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
76.9
Evidence status
confirmed · 97% mass
General preference
78.7
Coding
79.2
Agents & tools
56.6
Reasoning
45.4
Evidence breadth
100%
Evidence coverage
90%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
24.3
Liquidity (providers × uptime)
97.1
Open reach (HF downloads)
Surface (context / tools / modalities)
95.0
Freshness
75.0
  • · OpenRouter popularity #79
  • · 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
48.0
partial · 56% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
79.8
Evaluation provenance
89.8

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
48.9
OpenRouter weekly popularity
#79 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
#42 of 402
Rating
1468.1
95% confidence interval
1463–1473
Votes
30K
Source published at
13 Sept 2026, 00:00 UTC
Category
overall
Identity match confidence
100%

Market Gravity breakdown

Usage55%
24.3

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
97.1

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%
75.0

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

Specification

Context window
500K tokens
Max output
450K tokens
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

Benchmark leaderboards featuring Grok 4.5

All leaderboards
Public benchmark boards on which Grok 4.5 has a published result
LeaderboardScoreSource rankConfigurationPublished
Arena coding leaderboardArena (LMArena)15181511–1526#33 of 397Default13 Sept 2026
LMArena Agent leaderboardLMArena2.9%1.9%–3.9%#19 of 46Default15 Sept 2026
ARC-AGI-2 leaderboardARC Prize Foundation52.6%#71 of 214High21 Sept 2026
ARC-AGI-3 leaderboardARC Prize Foundation0.3%#27 of 39Medium21 Sept 2026
Artificial Analysis Intelligence IndexArtificial Analysis38.8#44 of 151intelligence-index:v4.3:high19 Sept 2026
Humanity's Last Exam (Artificial Analysis run)Artificial Analysis42.7%#40 of 615hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="Grok 4.5 (high)":reasoning=true5 Sept 2026
Terminal-Bench 4.0 leaderboardTerminal-Bench (Laude Institute)12.4%9.8%–15.0%#25 of 27Grok Build · High16 Jul 2026
WildClawBench OpenClaw leaderboardWildClawBench57.5#6 of 34Default20 Jul 2026

Grok 4.5: common questions

How does Grok 4.5 rank among AI models?

Grok 4.5 is a superseded version and is not on the current board as of 22 September 2026. Its archive position, where one exists, is shown on the page; the newer version carries the current rank.

How much does Grok 4.5 cost per 1M tokens?

Grok 4.5 is listed at $2.00 per 1M input tokens and $6.00 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 $7.00 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 Grok 4.5?

Grok 4.5 has a published context window of 500K tokens (500,000) and a maximum output of 450K tokens. Individual providers can serve less than the published maximum; the providers table lists each endpoint's own limit.

Is Grok 4.5 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 Grok 4.5?

One provider serves Grok 4.5 through OpenRouter as of 22 September 2026: xAI. Each provider's price, context limit, quantization and measured uptime are in the providers table above.

Which benchmarks has Grok 4.5 been evaluated on?

Grok 4.5 has published results on 8 public boards tracked by ModelCap as of 22 September 2026: Arena coding 1518 (#33 of 397), LMArena Agent 2.9% (#19 of 46), ARC-AGI-2 52.6% (#71 of 214), ARC-AGI-3 0.3% (#27 of 39) and AA Intelligence Index 38.8 (#44 of 151) and more. Each board page ranks every tracked model on that benchmark; the ModelCap Index combines them with published uncertainty.

When was Grok 4.5 released?

Grok 4.5 first appeared in the catalogue on 8 Jul 2026. It has since been superseded by Grok 4.7. Rank and price movements since then are recorded on the site's changes feed.