xAI, released Mar 9, 2026

Grok 4.20 (Reasoning)price, context, benchmarks and release details

Provisional: not enough results to rank yet 80% confidence 80 percent, High confidence, 3 of 7 expected sources in
57.7
SI Score
#73 of 142 ranked models
Input, per 1M tokens
$1.25models.devFirst-party hosted API; MIT models.dev transcription. Provider documentation: https://docs.x.ai/docs/models. Exact canonical endpoint; lowest short-context Standard USD token tier; cache/batch discounts excluded. Deprecated endpoints excluded; xai/grok-4.20-0309-reasoning Retrieved Oct 9, 2026 · MIT
Open source ↗
Output, per 1M tokens
$2.50models.devFirst-party hosted API; MIT models.dev transcription. Provider documentation: https://docs.x.ai/docs/models. Exact canonical endpoint; lowest short-context Standard USD token tier; cache/batch discounts excluded. Deprecated endpoints excluded; xai/grok-4.20-0309-reasoning Retrieved Oct 9, 2026 · MIT
Open source ↗
Context window
1Mmodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
Max output
30Kmodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
Released
Mar 9, 2026models.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗

How the score breaks down

Coding (weight 40 percent) —
Math (weight 15 percent) 43.2
Preference (weight 15 percent) 77.8
Reasoning (weight 30 percent) 65.2

Weights: reasoning 30%, math 15%, coding 40%, preference 15%. Results use fixed 0–100 scales before averaging, and thin evidence is pulled toward 50. Method si-v3-retained-evidence-2, computed Oct 9, 2026, 05:13 UTC.

Around it on the leaderboard

  1. 71 Fugu Ultra 57.9
  2. 72 MiniMax-M2.5 57.8
  3. 73 Grok 4.20 (Reasoning) 57.7
  4. 74 MiMo-V2.6-Pro 57.4
  5. 75 GPT-5.4 nano 57.4

Full leaderboard

Benchmark results

10 benchmarks, 10 results

Each row shows the best published result. Where a model was tested at several settings, such as reasoning effort, open the row to see each one. Hover or tap a value for its source.

ARC-AGI-1 (public eval)reasoning 95.5%ARC PrizeARC Prize steward-published result; exact edition/subset; publication time is HTTP Last-Modified of the aggregate export, not the evaluation date. [variant] grok-4.20-beta-0309b-reasoningPublished Oct 6, 2026 Retrieved Oct 9, 2026 · factual citation
Open source ↗ 95.5
ARC-AGI-1 (semi-private)reasoning 89.5%ARC PrizeARC Prize steward-published result; exact edition/subset; publication time is HTTP Last-Modified of the aggregate export, not the evaluation date. [variant] grok-4.20-beta-0309b-reasoningPublished Oct 6, 2026 Retrieved Oct 9, 2026 · factual citation
Open source ↗ 89.5
ARC-AGI-2 (public eval)reasoning 63.6%ARC PrizeARC Prize steward-published result; exact edition/subset; publication time is HTTP Last-Modified of the aggregate export, not the evaluation date. [variant] grok-4.20-beta-0309b-reasoningPublished Oct 6, 2026 Retrieved Oct 9, 2026 · factual citation
Open source ↗ 63.6
ARC-AGI-2 (semi-private)reasoning 65.1%ARC PrizeARC Prize steward-published result; exact edition/subset; publication time is HTTP Last-Modified of the aggregate export, not the evaluation date. [variant] grok-4.20-beta-0309b-reasoningPublished Oct 6, 2026 Retrieved Oct 9, 2026 · factual citation
Open source ↗ 65.1
ARC-AGI-3 (semi-private)reasoning 0.1%ARC PrizeARC Prize steward-published result; exact edition/subset; publication time is HTTP Last-Modified of the aggregate export, not the evaluation date. [variant] xai-grok-4-20-beta-0309-reasoningPublished Oct 6, 2026 Retrieved Oct 9, 2026 · factual citation
Open source ↗ 0.1
GPQA Diamondreasoning 89.3%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Jul 13, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 89.3
FrontierMath Tier 4 (v2)math 17.1%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Jul 13, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 17.1
FrontierMath Tiers 1–3 (v2)math 44.9%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Jul 13, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 44.9
OTIS Mock AIME 2024–2025math 92.2%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Jul 13, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 92.2
LMArena Textpreference 1450.8 eloLMArena / ArenaPublished source fact [variant] text / overallPublished Oct 8, 2026 Retrieved Oct 9, 2026 · CC-BY-4.0
Open source ↗ 77.8

Normalization uses a fixed 0–100 scale for each unit, independent of other models. Compare evaluation conditions before reading a small gap as decisive. “Lab-reported” marks the provider's own published figure.

Details and sources

Open weights
Nomodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
License
not yet reported
Input modalities
text, image, pdfmodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
First seen by SuperIndex
Oct 8, 2026
Coverage
64% of expected source weight

Reported (3)

  • ARC PrizeOct 8, 2026
  • Epoch AI BenchmarkingOct 8, 2026
  • LMArena / ArenaOct 8, 2026

Awaiting (4)

  • Humanity’s Last Exam13% of weight
  • Official model cards via models.dev4% of weight
  • LiveBench13% of weight
  • Terminal-Bench6% of weight

Confidence rises as pending sources publish. Some sources never cover some models, so confidence reaches 100% at 80% of expected weight.

What changed

All releases · RSS feed

Alerts on this device

What to be alerted about
RSS feed