GPT-5.3 Codex vs Muse Spark 1.1
Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Verdict
GPT-5.3 Codex leads for most workloads.
- Muse Spark 1.1 offers ~2.5× the context window — choose it for very long inputs.
Based on BenchLM composite scores, July 2026.
GPT-5.3 Codex
82
Muse Spark 1.1
78
Pick GPT-5.3 Codex if you want the stronger benchmark profile. Muse Spark 1.1 only becomes the better choice if agentic is the priority or you need the larger 1M context window.
Category Radar
Head-to-Head by Category
Category Breakdown
| Benchmark | GPT-5.3 Codex | Δ | Muse Spark 1.1 |
|---|---|---|---|
| Agentic | 71.4 | → 9.0 | 80.4 |
| Coding | 64.4 | ← 2.9 | 61.5 |
| Knowledge | — | — | 62.1 |
| Multimodal | — | — | 88.4 |
Operational Comparison
GPT-5.3 Codex
Muse Spark 1.1
$1.75 / $14
N/A
79 t/s
N/A
88.26s
N/A
400K
1M
Quick Verdict
Pick GPT-5.3 Codex if you want the stronger benchmark profile. Muse Spark 1.1 only becomes the better choice if agentic is the priority or you need the larger 1M context window.
GPT-5.3 Codex is clearly ahead on the provisional aggregate, 82 to 78. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.3 Codex's sharpest advantage is in coding, where it averages 64.4 against 61.5. The single biggest benchmark swing on the page is OSWorld-Verified, 64.7% to 80.8%. Muse Spark 1.1 does hit back in agentic, so the answer changes if that is the part of the workload you care about most.
Muse Spark 1.1 gives you the larger context window at 1M, compared with 400K for GPT-5.3 Codex.
Benchmark Deep Dive
Frequently Asked Questions (3)
Which is better, GPT-5.3 Codex or Muse Spark 1.1?
GPT-5.3 Codex is ahead on BenchLM's provisional leaderboard, 82 to 78. The biggest single separator in this matchup is OSWorld-Verified, where the scores are 64.7% and 80.8%.
Which is better for coding, GPT-5.3 Codex or Muse Spark 1.1?
GPT-5.3 Codex has the edge for coding in this comparison, averaging 64.4 versus 61.5. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, GPT-5.3 Codex or Muse Spark 1.1?
Muse Spark 1.1 has the edge for agentic tasks in this comparison, averaging 80.4 versus 71.4. Inside this category, JobBench is the benchmark that creates the most daylight between them.
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