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ModelDeprecatedClosed / proprietaryIdentity probable

Grok 4.20

xAIfamily · Grok 4.20docs.x.ai/developers/models/grok-4.20-0309-reaso

Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering...

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data quality68

Updated 4 h ago · first seen 11 Sept 2026

model_01M294WW257REBD60NE44YGEZQ

Overview

Identity

Canonical model
Yesidentity confidence: mediumOne row per real model release. Artifacts (checkpoints, quantisations, conversions) and folded evaluation variants point here.
Official checkpoints
None recorded — closed weightsofficial_checkpoints = hf_repo identifiers carried by the model itself; artifacts are separate entities pointing here through canonical_id.
Artifacts
None recordedSeparate entities (checkpoint · quantization · conversion · packaging) pointing to this model through canonical_id.
Provider deployments
2
API aliases
grok-4-20grok-4.20-0309-reasoningx-ai/grok-4.20Identifiers under which providers and evaluators refer to this model.
Folded evaluation variants
0Effort / thinking variants (…-high, …-non-reasoning) are result configurations of this model, not separate models. Their old URLs redirect here.

Openness

Closed / proprietary— weights not available; 7 dimensions unknown.

Weights are not available; the model is reachable only through an API or a product.

  • Weights

    No

  • Inference code

    —

  • Training code

    —

  • Training data

    —

  • Dataset

    —

  • Commercial use

    —

  • Redistribution

    —

  • Derivatives

    —

dimensions marked null are unknown, not false

Key facts

Release date

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Status

Source:Artificial AnalysisT2observed 13 h agomedium

Knowledge cutoff

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Official page
docs.x.ai/developers/models/grok-4.20-0309-reasoning

Source:xAI — docsT1observed 13 h agohigh

API model id

Source:xAI — docsT1observed 13 h agohigh

Openrouter id

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Architecture

Tokenizer

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Capabilities

Modalities

Modalities
imagetext
Input
textimage
Output
text

Capabilities

  • Tool calling

    Yes

    OpenRouter public model & pricing listing · T2

  • Structured output

    Yes

    OpenRouter public model & pricing listing · T2

  • Reasoning

    Yes

    OpenRouter public model & pricing listing · T2

  • Vision

    Yes

    OpenRouter public model & pricing listing · T2

  • Audio

    Unavailable

  • Fine-tuning available

    Unavailable

Context window

Source:xAI — docsT1observed 13 h agohigh

Max output

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Knowledge cutoff

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Tokenizer

Source:OpenRouter public model & pricing listingT2observed 15 h agomedium

Benchmarks21

Compare with another model →

Comparable same task and conditions · Partially comparable same task, conditions differ (effort, temperature, judge) · Not comparable different variant or metric

Benchmark results grouped by comparability group
Benchmark · groupBest scoreTrustConfigurationResultsvs leaderEvaluatedSource
Terminal-Benchagentic · accuracy · variant=hard · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisvarianthardreasoningonconditions differ across rows → partially comparable3−28.0 ptvs gpt-5.6-solobs. 12 Sept 2026artificialanalysis.aiT2
τ²-benchagentic · pass^1 · variant=Telecom · evaluator=Artificial AnalysisIndependentevaluatorArtificial AnalysisvariantTelecomreasoningonconditions differ across rows → partially comparable2non-primary groupobs. 12 Sept 2026artificialanalysis.aiT2
τ²-benchagentic · pass^1 · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysis1−6.14 ptvs Z.ai GLM 5.2obs. 11 Sept 2026artificialanalysis.aiT2
Artificial Analysis Intelligence Indexcomposite · indexIndependentreasoningonversion4.3conditions differ across rows → partially comparable3−27.7vs Claude Fable 5.1obs. 12 Sept 2026artificialanalysis.aiT2
IFBenchinstruction-following · accuracy · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisreasoningonconditions differ across rows → partially comparable3−2.11 ptvs Grok 4.3obs. 12 Sept 2026artificialanalysis.aiT2
Humanity's Last Examknowledge · accuracy · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisreasoningonconditions differ across rows → partially comparable3−24.6 ptvs Claude Fable 5.1obs. 12 Sept 2026artificialanalysis.aiT2
MMMU-Promultimodal · accuracy · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisreasoningonconditions differ across rows → partially comparable3−12.3 ptvs gpt-6-astraobs. 12 Sept 2026artificialanalysis.aiT2
GPQA Diamondreasoning · accuracy · variant=Diamond · evaluator=Artificial AnalysisIndependentevaluatorArtificial AnalysisvariantDiamondreasoningonconditions differ across rows → partially comparable2non-primary groupobs. 12 Sept 2026artificialanalysis.aiT2
GPQA Diamondreasoning · accuracy · variant=GPQA Diamond · evaluator=Artificial AnalysisIndependentevaluatorArtificial AnalysisvariantGPQA Diamond1−5.15 ptvs gpt-6-astraobs. 11 Sept 2026artificialanalysis.aiT2

Current rows only, grouped by benchmark → canonical metric → comparability group (task configuration). Effort variants folded into this model appear as rows of the same group. 21 current rows in total. “vs leader” compares with the current leader of the benchmark's primary group only; other groups are not directly comparable. Comparability rules →

Providers & Pricing3

All offers in the price terminal →
Provider deployments, cheapest output first
ProviderContextInput / 1MCached inOutput / 1MBatch in / outNative unitsStatusObservedSource
OpenRoutercheapest outputx-ai/grok-4.202Mout 1.8M$0.20——active2 h agosince 12 Sept 2026openrouter.aiT2
xAI APIgrok-4.20-0309-reasoning1M$0.20$1 / $2long_context_input_per_mtok=2.5long_context_output_per_mtok=5long_context_cached_input_per_mtok=0.4active2 h agosince 11 Sept 2026docs.x.aiT1
xAI APIx-ai/grok-4.202Mout 1.8M$0.20——active6 h agosince 11 Sept 2026openrouter.aiT2

USD per 1M tokens as published by each provider; native units (per-request fees, flex/priority tiers) are kept verbatim. Rows are append-only — every price change is kept in the history below. Cost of a workload →

Price history

Step lines per provider; amber markers are recorded changes. Click a marker or a row for the evidence behind that price.

Output price · USD / 1M tokens 2 providers

Output price history of Grok 4.20$0$1$2$3Sept 26Sept 26Sept 26Sept 26Sept 26xAI API: first observed → $2.5 · 11 Sept 2026OpenRouter: first observed → $2.5 · 12 Sept 2026
  • xAI API
  • OpenRouter
  • OpenRouterfirst observed $2.512 Sept 2026
  • xAI APIfirst observed $2.511 Sept 2026

Input price · USD / 1M tokens 2 providers

Input price history of Grok 4.20$0$0.50$1$1.5Sept 26Sept 26Sept 26Sept 26Sept 26xAI API: first observed → $1.25 · 11 Sept 2026OpenRouter: first observed → $1.25 · 12 Sept 2026
  • xAI API
  • OpenRouter
  • OpenRouterfirst observed $1.2512 Sept 2026
  • xAI APIfirst observed $1.2511 Sept 2026

Versions & Artifacts0

Version history

Context window1 change

11 Sept 2026→11 Sept 2026current

Knowledge cutofffirst observation only

11 Sept 2026current

Max outputfirst observation only

11 Sept 2026current

Opennessfirst observation only

11 Sept 2026current

Statusfirst observation only

11 Sept 2026current

Each hop is a claim: click a value for its source, tier and observation time. Nothing is overwritten — a new observation closes the previous claim.

Artifacts 0

No artifact (checkpoint, quantisation, conversion or packaging) points to this model yet.

Timeline17

Full timeline →

Change history

Temporal, append-only claims: a new observation closes the previous claim instead of overwriting it. Rewind the record with the as-of picker.
1 claims · 1 propertiesShow all properties

Aa deprecatedaa_deprecated1

Claim history for Aa deprecated
ValueValid from → toStatusSourceConfidenceExtractor
Yes → currentcurrentArtificial AnalysisT2mediumdeterministic

Claims are temporal and append-only: a new observation closes the previous claim (valid_to) instead of overwriting it. Conflicting claims from different sources are kept side by side and flagged — never averaged. Methodology →

Provenance

Attributed facts

29

Source tiers

T1T28 / 21

Freshest observation

4 h ago

Conflicts

10 flagged

Source documents 4

Source documents
SourceDocumentTypeTierLast observedSnapshots
xAI — docsdocs.x.ai/developers/models/grok-4.20-0309-reasoning.md model_pageT1· Official2 h ago1
xAI — docsdocs.x.ai/developers/models model_docsT1· Official2 h ago10
OpenRouter public model & pricing listingopenrouter.ai/api/v1/models catalogueT2· Quality secondary2 h ago11
Artificial Analysisartificialanalysis.ai/leaderboards/models leaderboardT2· Quality secondary5 h ago2

Tier 1 = official/primary, 2 = quality secondary, 3 = community, 4 = unverified. Every snapshot is archived; see all sources and the methodology.

Data quality (68/100) measures how well AI Atlas knows this entity — completeness, primary-source ratio, freshness, conflicts — never how good the model is. Methodology →