Model comparison
GPT-5.1-Codex vs Grok 4.20 Multi-Agent
Grok 4.20 Multi-Agent is the stronger model overall, scoring 46.2 to 38.6 on the Noometry Index.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in math, where Grok 4.20 Multi-Agent leads 39.4 to 30.3.
- Grok 4.20 Multi-Agent is cheaper at $1.25 / $2.50 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- Grok 4.20 Multi-Agent accepts more context: 1M tokens versus 400K.
Side by side
| GPT-5.1-Codex | Grok 4.20 Multi-Agent | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 38.6 | 46.2 |
| Released | 2025-11-12 | 2026-03-09 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | 1M |
| Max output | 128K | 30K |
| Input $ / M tokens | $1.25 | $1.25 |
| Output $ / M tokens | $10 | $2.50 |
| Results tracked | 6 | 20 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Grok 4.20 Multi-Agent leads
GPT-5.1-Codex: 41.9 (#116), Grok 4.20 Multi-Agent: 43.0 (#92)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| LMArena Coding | — | 1457 |
| ALE-Bench | 1,245 | — |
Agentic & Tool Use Not comparable
GPT-5.1-Codex: 38.0 (#33), Grok 4.20 Multi-Agent: —
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| LMArena Search | — | 1204 |
| METR Time Horizons | 70.8% | — |
Reasoning Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 43.9 (#48)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| NYT Connections (extended) | — | 89.6% |
| LMArena Hard Prompts | — | 1448 |
Math Grok 4.20 Multi-Agent leads
GPT-5.1-Codex: 30.3 (#235), Grok 4.20 Multi-Agent: 39.4 (#104)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| ProofBench | 9% | — |
| LMArena Math | — | 1442 |
Knowledge Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 40.4 (#119)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Expert | — | 1445 |
Multimodal Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 40.5 (#48)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Vision | — | 1259 |
Multilingual Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 54.4 (#43)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Non-English | — | 1440 |
| LMArena Chinese | — | 1475 |
| LMArena French | — | 1466 |
| LMArena German | — | 1456 |
| LMArena Japanese | — | 1405 |
| LMArena Korean | — | 1416 |
| LMArena Russian | — | 1457 |
| LMArena Spanish | — | 1447 |
Instruction Following Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 74.8 (#84)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Instruction Following | — | 1420 |
Long Context Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 43.7 (#88)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Longer Query | — | 1431 |
Writing & Preference Not comparable
GPT-5.1-Codex: —, Grok 4.20 Multi-Agent: 64.0 (#59)
| Benchmark | GPT-5.1-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Text | — | 1450 |
| LMArena Creative Writing | — | 1436 |
| LMArena Multi-Turn | — | 1452 |
Frequently asked questions
Is GPT-5.1-Codex better than Grok 4.20 Multi-Agent?
Grok 4.20 Multi-Agent is the stronger model overall, scoring 46.2 to 38.6 on the Noometry Index.
Which is cheaper, GPT-5.1-Codex or Grok 4.20 Multi-Agent?
Grok 4.20 Multi-Agent is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.
Is GPT-5.1-Codex or Grok 4.20 Multi-Agent better for coding?
Grok 4.20 Multi-Agent scores higher on coding benchmarks: 43.0 versus 41.9 in the Noometry coding category.
Which has the bigger context window?
Grok 4.20 Multi-Agent does, with 1M tokens against 400K.
How many benchmarks do GPT-5.1-Codex and Grok 4.20 Multi-Agent share?
0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Grok 4.20 Multi-Agent has 20.