Model comparison
Grok 4.1 Fast vs Mercury
Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 37.6 on the Noometry Index.
Last verified . 8 shared benchmarks.
Summary
- They share 8 benchmarks with published results for both. Grok 4.1 Fast scores higher in 5 categories and Mercury in 1 category; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 17.5.
Side by side
| Grok 4.1 Fast | Mercury | |
|---|---|---|
| Provider | xAI | Inception |
| Noometry Index | 41.4 | 37.6 |
| Released | 2025-06-27 | — |
| Weights | Proprietary | Proprietary |
| Context window | 128K | — |
| Max output | 30K | — |
| Input $ / M tokens | $0.20 | — |
| Output $ / M tokens | $0.50 | — |
| Results tracked | 32 | 9 |
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Category by category
Coding Mercury leads
Grok 4.1 Fast: 34.1 (#245), Mercury: 38.7 (#170)
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Coding | 1411 | 1322 |
| LMArena WebDev | 1242 | — |
| ALE-Bench | 394.93 | — |
Agentic & Tool Use Not comparable
Grok 4.1 Fast: 36.3 (#39), Mercury: —
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| Berkeley Function Calling Leaderboard | 69.6% | — |
| τ²-bench Banking | 13.1% | — |
| LMArena Search | 1171 | — |
| Vending-Bench 2 | 1,107 | — |
Reasoning Grok 4.1 Fast leads
Grok 4.1 Fast: 43.4 (#49), Mercury: 17.5 (#293)
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1285 |
| SimpleBench | 56% | — |
| Kagi LLM Benchmark | — | 21.6% |
| NYT Connections (extended) | 87.4% | — |
| DTBench | 87.7% | — |
| ForecastBench | 61 | — |
Math Not comparable
Grok 4.1 Fast: 31.9 (#221), Mercury: —
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| MathArena Final-Answer Competitions | 60.9% | — |
| ProofBench | 4% | — |
| LMArena Math | 1408 | — |
Knowledge Not comparable
Grok 4.1 Fast: 33.1 (#207), Mercury: —
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| Vectara Hallucination Rate | 17.8% | — |
| LMArena Expert | 1399 | — |
Multimodal Not comparable
Grok 4.1 Fast: 37.0 (#76), Mercury: —
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Vision | 1201 | — |
Multilingual Grok 4.1 Fast leads
Grok 4.1 Fast: 51.0 (#114), Mercury: 41.6 (#206)
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Non-English | 1391 | 1260 |
| LMArena Chinese | 1441 | — |
| LMArena French | 1415 | — |
| LMArena German | 1404 | — |
| LMArena Japanese | 1349 | — |
| LMArena Korean | 1361 | — |
| LMArena Russian | 1387 | — |
| LMArena Spanish | 1413 | — |
Instruction Following Grok 4.1 Fast leads
Grok 4.1 Fast: 72.7 (#133), Mercury: 65.2 (#224)
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Instruction Following | 1376 | 1239 |
Long Context Grok 4.1 Fast leads
Grok 4.1 Fast: 42.4 (#126), Mercury: 38.4 (#198)
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Longer Query | 1390 | 1266 |
Writing & Preference Grok 4.1 Fast leads
Grok 4.1 Fast: 57.2 (#131), Mercury: 46.2 (#221)
| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Text | 1408 | 1282 |
| LMArena Creative Writing | 1394 | 1191 |
| LMArena Multi-Turn | 1389 | 1282 |
| EQ-Bench Creative Writing | 1327 | — |
Frequently asked questions
Is Grok 4.1 Fast better than Mercury?
Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 37.6 on the Noometry Index.
Is Grok 4.1 Fast or Mercury better for coding?
Mercury scores higher on coding benchmarks: 38.7 versus 34.1 in the Noometry coding category.
How many benchmarks do Grok 4.1 Fast and Mercury share?
8 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Mercury has 9.