GPT-5.3-Codex vs Muse Spark 1.1
GPT-5.3-Codex 
Muse Spark 1.1 Verdict
- Muse Spark 1.1 leads on quality: 65.0 vs 62.5.
- GPT-5.3-Codex is stronger in long context.
- Muse Spark 1.1 is stronger in coding, composite, instruction following, knowledge, multimodal, human preference, maths, reasoning.
- Muse Spark 1.1 is 2.4× cheaper ($2.00 vs $4.81 per 1M blended).
- Muse Spark 1.1 streams 1.6× faster (194 vs 121 tokens per second).
| Metric | GPT-5.3-Codex | Muse Spark 1.1 |
|---|---|---|
| BenchLeader Index | 62.5 | 65.0 |
| Agents & tools score | 62.7 | 62.7 |
| Coding score | 54.8 | 68.1 |
| Composite score | 70.1 | 72.3 |
| Instruction following score | 73.2 | 77.8 |
| Knowledge score | 69.3 | 73.2 |
| Long context score | 68.3 | 65.4 |
| Multimodal score | 63.0 | 65.0 |
| Human preference score | – | 66.3 |
| Maths score | – | 52.2 |
| Reasoning score | – | 69.2 |
| Blended price $/M | $4.81 | $2.00 |
| Output speed | 121 tok/s | 194 tok/s |
| Time to first answer | 58.2 s | 2.6 s |
| Context window | 400k | 1.0M |
| SimpleQA Verified | – | 57.8% |
| Terminal-Bench | 78.4% | – |
| SciCode | – | 58.2% |
| WeirdML | 79.3% | – |
| APEX-Agents | 31.8% | 41.9% |
| ProofBench | – | 39.0% |
| Epoch Capabilities Index | 156.6 | 154.6 |
| LMArena Text | – | 1492 |
| LMArena Hard Prompts | – | 1511 |
| LMArena Coding | – | 1531 |
| LMArena WebDev | 1409 | 1541 |
| LMArena Vision | – | 1293 |
| LMArena Agent | – | -2.6 |
| AA Intelligence Index | 32.5 | 34.3 |
| IFBench | 75.4% | – |
| AA-LCR | 83.3% | 77.7% |
| MMMU-Pro | 78.5% | – |
| AA-Omniscience | 10.9 | 28.1 |
| Terminal-Bench Hard | 53.0% | – |
| GPQA Diamond (AA) | 91.5% | 89.8% |
| Humanity's Last Exam (AA) | 42.5% | 46.2% |
| SciCode (AA) | – | 58.8% |
| τ²-Bench Telecom (AA) | 86.0% | – |
| SWE-Bench Pro | – | 61.5% |
| MCP Atlas | – | 88.1% |
| MultiChallenge | – | 75.3% |
| PRBench Finance | – | 55.0% |
| PRBench Legal | – | 57.0% |
| MultiNRC | – | 65.6% |
| HiL-Bench | 4.3% | – |
| EQ-Bench 4 | – | 1260 |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
GPT-5.3-Codex vs Muse Spark 1.1: questions
- Is GPT-5.3-Codex better than Muse Spark 1.1?
- Muse Spark 1.1 leads on quality: 65.0 vs 62.5. The BenchLeader Index combines every independent quality benchmark; Muse Spark 1.1 is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is GPT-5.3-Codex better than Muse Spark 1.1 for coding?
- Muse Spark 1.1 scores higher in coding (68 vs 55 on the category index, where 50 is average).
- Is GPT-5.3-Codex better than Muse Spark 1.1 for agentic tasks?
- They are level in agentic tasks (63 each).
- Which is cheaper, GPT-5.3-Codex or Muse Spark 1.1?
- Muse Spark 1.1 is cheaper: $2.00 against $4.81 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.3-Codex or Muse Spark 1.1?
- Muse Spark 1.1 streams faster: 194 against 121 output tokens per second.
- Which has the larger context window?
- Muse Spark 1.1 accepts more context: 1.0M against 400k tokens.