Model comparison
Grok 4.1 Fast vs Phi 3 Medium 4k Instruct
Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 33.0 on the Noometry Index.
Last verified . 17 shared benchmarks.
MicrosoftSummary
- They share 17 benchmarks with published results for both. Grok 4.1 Fast scores higher in 7 categories and Phi 3 Medium 4k Instruct in 1 category; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Grok 4.1 Fast leads 57.2 to 34.1.
- Phi 3 Medium 4k Instruct has downloadable open weights; the other is API-only.
Side by side
| Grok 4.1 Fast | Phi 3 Medium 4k Instruct | |
|---|---|---|
| Provider | xAI | Microsoft |
| Noometry Index | 41.4 | 33.0 |
| Released | 2025-06-27 | — |
| Weights | Proprietary | Open |
| Context window | 128K | — |
| Max output | 30K | — |
| Input $ / M tokens | $0.20 | — |
| Output $ / M tokens | $0.50 | — |
| Results tracked | 32 | 17 |
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Category by category
Coding Grok 4.1 Fast leads
Grok 4.1 Fast: 34.1 (#245), Phi 3 Medium 4k Instruct: 32.9 (#268)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Coding | 1411 | 1130 |
| LMArena WebDev | 1242 | — |
| ALE-Bench | 394.93 | — |
Agentic & Tool Use Not comparable
Grok 4.1 Fast: 36.3 (#39), Phi 3 Medium 4k Instruct: —
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| 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), Phi 3 Medium 4k Instruct: 21.7 (#214)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1127 |
| SimpleBench | 56% | — |
| NYT Connections (extended) | 87.4% | — |
| DTBench | 87.7% | — |
| ForecastBench | 61 | — |
Math Phi 3 Medium 4k Instruct leads
Grok 4.1 Fast: 31.9 (#221), Phi 3 Medium 4k Instruct: 33.4 (#202)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Math | 1408 | 1173 |
| MathArena Final-Answer Competitions | 60.9% | — |
| ProofBench | 4% | — |
Knowledge Grok 4.1 Fast leads
Grok 4.1 Fast: 33.1 (#207), Phi 3 Medium 4k Instruct: 30.2 (#229)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Expert | 1399 | 1108 |
| Vectara Hallucination Rate | 17.8% | — |
Multimodal Not comparable
Grok 4.1 Fast: 37.0 (#76), Phi 3 Medium 4k Instruct: —
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Vision | 1201 | — |
Multilingual Grok 4.1 Fast leads
Grok 4.1 Fast: 51.0 (#114), Phi 3 Medium 4k Instruct: 30.6 (#263)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Non-English | 1391 | 1094 |
| LMArena Chinese | 1441 | 1108 |
| LMArena French | 1415 | 1110 |
| LMArena German | 1404 | 1101 |
| LMArena Japanese | 1349 | 1042 |
| LMArena Korean | 1361 | 954 |
| LMArena Russian | 1387 | 1145 |
| LMArena Spanish | 1413 | 1095 |
Instruction Following Grok 4.1 Fast leads
Grok 4.1 Fast: 72.7 (#133), Phi 3 Medium 4k Instruct: 57.6 (#268)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Instruction Following | 1376 | 1113 |
Long Context Grok 4.1 Fast leads
Grok 4.1 Fast: 42.4 (#126), Phi 3 Medium 4k Instruct: 34.0 (#255)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Longer Query | 1390 | 1120 |
Writing & Preference Grok 4.1 Fast leads
Grok 4.1 Fast: 57.2 (#131), Phi 3 Medium 4k Instruct: 34.1 (#272)
| Benchmark | Grok 4.1 Fast | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Text | 1408 | 1138 |
| LMArena Creative Writing | 1394 | 1107 |
| LMArena Multi-Turn | 1389 | 1088 |
| EQ-Bench Creative Writing | 1327 | — |
Frequently asked questions
Is Grok 4.1 Fast better than Phi 3 Medium 4k Instruct?
Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 33.0 on the Noometry Index.
Is Grok 4.1 Fast or Phi 3 Medium 4k Instruct better for coding?
Grok 4.1 Fast scores higher on coding benchmarks: 34.1 versus 32.9 in the Noometry coding category.
How many benchmarks do Grok 4.1 Fast and Phi 3 Medium 4k Instruct share?
17 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Phi 3 Medium 4k Instruct has 17.