Model comparison
GPT-5.3 Codex vs Grok Build 0.1
GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 36.4 on the Noometry Index. Grok Build 0.1 costs 3.9× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 48.0 to 22.7.
- Grok Build 0.1 is cheaper at $1 / $2 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- GPT-5.3 Codex accepts more context: 400K tokens versus 256K.
Side by side
| GPT-5.3 Codex | Grok Build 0.1 | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 45.8 | 36.4 |
| Released | 2026-02-05 | 2026-04-16 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | 256K |
| Max output | 128K | 256K |
| Input $ / M tokens | $1.75 | $1 |
| Output $ / M tokens | $14 | $2 |
| Results tracked | 8 | 3 |
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Category by category
Coding GPT-5.3 Codex leads
GPT-5.3 Codex: 48.6 (#56), Grok Build 0.1: 43.1 (#91)
| Benchmark | GPT-5.3 Codex | Grok Build 0.1 |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| SciCode | — | 50.2% |
| WeirdML | 79.3% | — |
| ALE-Bench | 1,655 | — |
Agentic & Tool Use GPT-5.3 Codex leads
GPT-5.3 Codex: 48.0 (#9), Grok Build 0.1: 22.7 (#129)
| Benchmark | GPT-5.3 Codex | Grok Build 0.1 |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| GBAEval | — | 2.4% |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |
Reasoning Not comparable
GPT-5.3 Codex: —, Grok Build 0.1: 32.2 (#77)
| Benchmark | GPT-5.3 Codex | Grok Build 0.1 |
|---|---|---|
| CritPt | — | 9.1% |
| Epoch Capabilities Index | 156.77 | — |
Frequently asked questions
Is GPT-5.3 Codex better than Grok Build 0.1?
GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 36.4 on the Noometry Index. Grok Build 0.1 costs 3.9× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.
Which is cheaper, GPT-5.3 Codex or Grok Build 0.1?
Grok Build 0.1 is cheaper. It lists at $1 per million input tokens and $2 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.
Is GPT-5.3 Codex or Grok Build 0.1 better for coding?
GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 43.1 in the Noometry coding category.
Which has the bigger context window?
GPT-5.3 Codex does, with 400K tokens against 256K.
How many benchmarks do GPT-5.3 Codex and Grok Build 0.1 share?
0 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Grok Build 0.1 has 3.