Model comparison
GPT-5.4 Pro vs Grok 4.1 Fast
GPT-5.4 Pro is the stronger model overall, scoring 58.8 to 40.9 on the Noometry Index. Grok 4.1 Fast costs 245× less per token, which makes it the better buy when GPT-5.4 Pro's lead doesn't matter for your workload.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. GPT-5.4 Pro scores higher in 4 categories and Grok 4.1 Fast in 0 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5.4 Pro leads 72.0 to 30.9.
- The biggest single-benchmark swing is SimpleBench: 74.1% for GPT-5.4 Pro and 56% for Grok 4.1 Fast.
- Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $30 / $180 for GPT-5.4 Pro.
- GPT-5.4 Pro accepts more context: 1.05M tokens versus 128K.
Side by side
| GPT-5.4 Pro | Grok 4.1 Fast | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 58.8 | 40.9 |
| Released | 2026-03-05 | 2025-06-27 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 128K |
| Max output | 128K | 30K |
| Input $ / M tokens | $30 | $0.20 |
| Output $ / M tokens | $180 | $0.50 |
| Results tracked | 16 | 32 |
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Category by category
Coding GPT-5.4 Pro leads
GPT-5.4 Pro: 42.6 (#89), Grok 4.1 Fast: 33.8 (#236)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| LMArena WebDev | — | 1241 |
| WeirdML | 57.4% | — |
| LMArena Coding | — | 1411 |
| ALE-Bench | — | 394.93 |
Agentic & Tool Use Not comparable
GPT-5.4 Pro: —, Grok 4.1 Fast: 36.1 (#35)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | — | 1,107 |
Reasoning GPT-5.4 Pro leads
GPT-5.4 Pro: 71.0 (#10), Grok 4.1 Fast: 42.3 (#45)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | 74.1% | 56% |
| ARC-AGI-2 | 83.3% | — |
| NYT Connections (extended) | — | 87.4% |
| ARC-AGI-1 | 94.5% | — |
| CritPt | 30% | — |
| Chess Puzzles | 58.6% | — |
| EnigmaEval | 23.8% | — |
| LMArena Hard Prompts | — | 1407 |
| DTBench | — | 87.7% |
| Epoch Capabilities Index | 159.12 | — |
| ForecastBench | — | 61 |
Math GPT-5.4 Pro leads
GPT-5.4 Pro: 72.0 (#17), Grok 4.1 Fast: 30.9 (#201)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| FrontierMath (Tiers 1-3) | 82.5% | — |
| FrontierMath Tier 4 | 58.5% | — |
| MathArena Final-Answer Competitions | — | 60.9% |
| ProofBench | — | 4% |
| LMArena Math | — | 1408 |
| FrontierMath (Feb 2025 set) | 50% | — |
| FrontierMath Tier 4 (v1) | 37.5% | — |
Knowledge GPT-5.4 Pro leads
GPT-5.4 Pro: 68.3 (#6), Grok 4.1 Fast: 32.6 (#203)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| Vectara Hallucination Rate | 8.3% | 17.8% |
| GPQA Diamond | 94.6% | — |
| Humanity's Last Exam | 44.3% | — |
| SimpleQA Verified | 46.3% | — |
| LMArena Expert | — | 1398 |
Multimodal Not comparable
GPT-5.4 Pro: —, Grok 4.1 Fast: 36.3 (#71)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |
Multilingual Not comparable
GPT-5.4 Pro: —, Grok 4.1 Fast: 51.1 (#110)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | — | 1391 |
| LMArena Chinese | — | 1441 |
| LMArena French | — | 1416 |
| LMArena German | — | 1404 |
| LMArena Japanese | — | 1347 |
| LMArena Korean | — | 1361 |
| LMArena Russian | — | 1387 |
| LMArena Spanish | — | 1411 |
Instruction Following Not comparable
GPT-5.4 Pro: —, Grok 4.1 Fast: 72.8 (#127)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | — | 1376 |
Long Context Not comparable
GPT-5.4 Pro: —, Grok 4.1 Fast: 42.4 (#121)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | — | 1390 |
Writing & Preference Not comparable
GPT-5.4 Pro: —, Grok 4.1 Fast: 57.4 (#126)
| Benchmark | GPT-5.4 Pro | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | — | 1408 |
| LMArena Creative Writing | — | 1394 |
| EQ-Bench Creative Writing | — | 1327 |
| LMArena Multi-Turn | — | 1389 |
Frequently asked questions
Is GPT-5.4 Pro better than Grok 4.1 Fast?
GPT-5.4 Pro is the stronger model overall, scoring 58.8 to 40.9 on the Noometry Index. Grok 4.1 Fast costs 245× less per token, which makes it the better buy when GPT-5.4 Pro's lead doesn't matter for your workload.
Which is cheaper, GPT-5.4 Pro or Grok 4.1 Fast?
Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; GPT-5.4 Pro lists at $30 and $180.
Is GPT-5.4 Pro or Grok 4.1 Fast better for coding?
GPT-5.4 Pro scores higher on coding benchmarks: 42.6 versus 33.8 in the Noometry coding category.
Which has the bigger context window?
GPT-5.4 Pro does, with 1.05M tokens against 128K.
How many benchmarks do GPT-5.4 Pro and Grok 4.1 Fast share?
2 benchmarks have published results for both models. GPT-5.4 Pro has 16 scored results on Noometry and Grok 4.1 Fast has 32.