Compare / head-to-head
Grok 4 Fast ReasoningvsSonar Pro
Grok 4 Fast Reasoning and Sonar Pro do not yet share a public benchmark, so quality cannot be compared apples-to-apples. Grok 4 Fast Reasoning is 25.7x cheaper per token. Grok 4 Fast Reasoning has the larger context window (2M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0
no overlap yet
Cheaper per token
Grok 4 Fast Reasoning
25.7x cheaper, input + output
Larger context
Grok 4 Fast Reasoning
2M tokens
Provider uptime (30d)
— · 100%
xAI · Perplexity
Grok 4 Fast Reasoning
xAI · released 2025-09-19
text
Quality
Benchmark matrix
0 shared · 12 only Grok 4 Fast Reasoning · 1 only Sonar Pro| Benchmark | Grok 4 Fast Reasoning | Sonar Pro | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 0 | ||||
| No public benchmark is reported for both models yet. | ||||
| Only Grok 4 Fast Reasoning reports · 12 | ||||
| GPQA Diamond | 85.7% ↗ | not reported | — | — |
| AIME 2025 | 92% ↗ | not reported | — | — |
| Humanity's Last Exam (no tools) | 20% ↗ | not reported | — | — |
| BrowseComp | 44.9% ↗ | not reported | — | — |
| BrowseComp (zh) | 51.2% ↗ | not reported | — | — |
| HMMT 2025 (no tools) | 93.3% ↗ | not reported | — | — |
| LiveCodeBench (Jan-May) | 80% ↗ | not reported | — | — |
| Reka Research Eval | 66% ↗ | not reported | — | — |
| Search Arena Elo | 1163 ↗ | not reported | — | — |
| SimpleQA | 95% ↗ | not reported | — | — |
| X Bench Deepsearch (zh) | 74% ↗ | not reported | — | — |
| X Browse | 58% ↗ | not reported | — | — |
| Only Sonar Pro reports · 1 | ||||
| SimpleQA F-score | not reported | 85.8% ↗ | — | — |
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 Fast Reasoning minus Sonar Pro 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 Fast Reasoning | Sonar Pro | Edge |
|---|---|---|---|
| Context window | 2M tokens | 200K tokens | Grok 4 Fast Reasoning |
| Max output | — | — | — |
| Input price / 1M | $0.2 ↗ | $3 ↗ | Grok 4 Fast Reasoning |
| Output price / 1M | $0.5 ↗ | $15 ↗ | Grok 4 Fast Reasoning |
| Cached input / 1M | $0.05 ↗ | — | — |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $0.7 | $18 | Grok 4 Fast Reasoning |
| Modalities | text | text | Tie |
| Released | 2025-09-19 | 2025-01-21 | — |
| Cited benchmark scores | 12 | 1 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Grok 4 Fast Reasoning vs …
Models sharing the most benchmarksMore matchups
Sonar Pro vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Grok 4 Fast Reasoning and Sonar Pro on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.