Compare / head-to-head
GLM-5.1vsGrok 4.20 Reasoning
GLM-5.1 leads 3 of 4 shared benchmarks. Grok 4.20 Reasoning is 1.5x 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
3 – 1
GLM-5.1 leads
Cheaper per token
Grok 4.20 Reasoning
1.5x cheaper, input + output
Larger context
Grok 4.20 Reasoning
1M tokens
Provider uptime (30d)
— · —
Z.ai · xAI
GLM-5.1
Z.ai · released 2026-04-07
text
Grok 4.20 Reasoning
xAI · released 2026-03-09
textvision
Quality
Benchmark matrix
4 shared · 3 only GLM-5.1 · 1 only Grok 4.20 Reasoning| Benchmark | GLM-5.1 | Grok 4.20 Reasoning | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 4 | ||||
| GPQA Diamond | 89.9% ↗epoch | 89.3% ↗epoch | +0.6 pt | GLM-5.1 |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 36.8% ↗epoch | 44.9% ↗epoch | -8.1 pt | Grok 4.20 Reasoning |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 93.3% ↗epoch | 92.2% ↗epoch | +1.1 pt | GLM-5.1 |
| SimpleQA Verified | 34% ↗epoch | 30.2% ↗epoch | +3.8 pt | GLM-5.1 |
| Only GLM-5.1 reports · 3 | ||||
| AIME 2026 | 95.8% ↗matharena ⚠ | not reported | — | — |
| LMArena Elo | 1462.4 ↗ | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 74.2% ↗epoch | not reported | — | — |
| Only Grok 4.20 Reasoning reports · 1 | ||||
| FrontierMath Tier 4 v2 (Epoch AI run) | not reported | 17.1% ↗epoch | — | — |
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 GLM-5.1 minus Grok 4.20 Reasoning 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 | GLM-5.1 | Grok 4.20 Reasoning | Edge |
|---|---|---|---|
| Context window | 200K tokens | 1M tokens | Grok 4.20 Reasoning |
| Max output | 131K tokens | — | — |
| Input price / 1M | $1.4 ↗ | $1.25 ↗ | Grok 4.20 Reasoning |
| Output price / 1M | $4.4 ↗ | $2.5 ↗ | Grok 4.20 Reasoning |
| Cached input / 1M | $0.26 ↗ | $0.2 ↗ | Grok 4.20 Reasoning |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $5.8 | $3.75 | Grok 4.20 Reasoning |
| Modalities | text | text · vision | Grok 4.20 Reasoning |
| Released | 2026-04-07 | 2026-03-09 | — |
| Cited benchmark scores | 7 | 5 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GLM-5.1 vs …
Models sharing the most benchmarksMore matchups
Grok 4.20 Reasoning vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GLM-5.1 and Grok 4.20 Reasoning on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.