Compare / head-to-head
Grok 4.20 ReasoningvsGrok 4.5
Grok 4.5 leads 5 of 5 shared benchmarks. Grok 4.20 Reasoning is 2.1x cheaper per token. Grok 4.20 Reasoning has the larger context window (1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0 – 5
Grok 4.5 leads
Cheaper per token
Grok 4.20 Reasoning
2.1x cheaper, input + output
Larger context
Grok 4.20 Reasoning
1M tokens
Provider uptime (30d)
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xAI
Grok 4.20 Reasoning
xAI · released 2026-03-09
textvision
Quality
Benchmark matrix
5 shared · 0 only Grok 4.20 Reasoning · 1 only Grok 4.5| Benchmark | Grok 4.20 Reasoning | Grok 4.5 | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 5 | ||||
| GPQA Diamond | 89.3% ↗epoch | 93.4% ↗epoch | -4.1 pt | Grok 4.5 |
| FrontierMath Tier 4 v2 (Epoch AI run) | 17.1% ↗epoch | 24.4% ↗epoch | -7.3 pt | Grok 4.5 |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 44.9% ↗epoch | 57.2% ↗epoch | -12.3 pt | Grok 4.5 |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 92.2% ↗epoch | 97.8% ↗epoch | -5.6 pt | Grok 4.5 |
| SimpleQA Verified | 30.2% ↗epoch | 48.3% ↗epoch | -18.1 pt | Grok 4.5 |
| Only Grok 4.20 Reasoning reports · 0 | ||||
| Grok 4.20 Reasoning reports nothing Grok 4.5 does not. | ||||
| Only Grok 4.5 reports · 1 | ||||
| LMArena Elo | not reported | 1450.1 ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Grok 4.20 Reasoning minus Grok 4.5 in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | Grok 4.20 Reasoning | Grok 4.5 | Edge |
|---|---|---|---|
| Context window | 1M tokens | 500K tokens | Grok 4.20 Reasoning |
| Max output | — | — | — |
| Input price / 1M | $1.25 ↗ | $2 ↗ | Grok 4.20 Reasoning |
| Output price / 1M | $2.5 ↗ | $6 ↗ | Grok 4.20 Reasoning |
| Cached input / 1M | $0.2 ↗ | $0.3 ↗ | Grok 4.20 Reasoning |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $3.75 | $8 | Grok 4.20 Reasoning |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-03-09 | 2026-07-08 | — |
| Cited benchmark scores | 5 | 6 | — |
Reliability
xAI status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Grok 4.20 Reasoning vs …
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Grok 4.5 vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Grok 4.20 Reasoning and Grok 4.5 on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.