Model comparison
GPT-5-Codex vs Hy4 preview
Hy4 preview is the stronger model overall, scoring 45.3 to 37.9 on the Noometry Index.
Last verified . 0 shared benchmarks.
TencentSummary
- The widest gap is in coding, where Hy4 preview leads 51.6 to 42.4.
- Hy4 preview is cheaper at $0.75 / $2.25 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- Hy4 preview accepts more context: 1.05M tokens versus 400K.
- Hy4 preview has downloadable open weights; the other is API-only.
Side by side
| GPT-5-Codex | Hy4 preview | |
|---|---|---|
| Provider | OpenAI | Tencent |
| Noometry Index | 37.9 | 45.3 |
| Released | 2025-09-15 | 2026-08-28 |
| Weights | Proprietary | Open |
| Context window | 400K | 1.05M |
| Max output | 128K | 64K |
| Input $ / M tokens | $1.25 | $0.75 |
| Output $ / M tokens | $10 | $2.25 |
| Results tracked | 3 | 3 |
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Category by category
Coding Hy4 preview leads
GPT-5-Codex: 42.4 (#103), Hy4 preview: 51.6 (#38)
| Benchmark | GPT-5-Codex | Hy4 preview |
|---|---|---|
| LMArena WebDev | — | 1632 |
| WeirdML | 54.5% | — |
Agentic & Tool Use Not comparable
GPT-5-Codex: 31.0 (#72), Hy4 preview: —
| Benchmark | GPT-5-Codex | Hy4 preview |
|---|---|---|
| Terminal-Bench | 44.3% | — |
Reasoning Too close to call
GPT-5-Codex: 30.9 (#83), Hy4 preview: 31.9 (#79)
| Benchmark | GPT-5-Codex | Hy4 preview |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | — |
| NYT Connections (extended) | — | 68.2% |
Math Not comparable
GPT-5-Codex: —, Hy4 preview: 55.7 (#42)
| Benchmark | GPT-5-Codex | Hy4 preview |
|---|---|---|
| ProofBench | — | 75% |
Frequently asked questions
Is GPT-5-Codex better than Hy4 preview?
Hy4 preview is the stronger model overall, scoring 45.3 to 37.9 on the Noometry Index.
Which is cheaper, GPT-5-Codex or Hy4 preview?
Hy4 preview is cheaper. It lists at $0.75 per million input tokens and $2.25 per million output tokens; GPT-5-Codex lists at $1.25 and $10.
Is GPT-5-Codex or Hy4 preview better for coding?
Hy4 preview scores higher on coding benchmarks: 51.6 versus 42.4 in the Noometry coding category.
Which has the bigger context window?
Hy4 preview does, with 1.05M tokens against 400K.
How many benchmarks do GPT-5-Codex and Hy4 preview share?
0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Hy4 preview has 3.