Model comparison
GPT-5.3 Codex vs Nova Pro
Head-to-head evidence from 12 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.3 Codex #26 (Supported); Nova Pro #196 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.3 Codex and Nova Pro share 12 comparable benchmark results. 0 of 8 categories are comparable. 9 results are unique to GPT-5.3 Codex; 0 to Nova Pro.
Updated July 20, 2026- Shared results
- 12
- GPT-5.3 Codex only
- 9
- Nova Pro only
- 0
- Comparable categories
- 0 / 8
Benchmark data for GPT-5.3 Codex and Nova Pro is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 6 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
GPT-5.3 Codex has the larger context window at 400K, compared with 128K for Nova Pro.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | GPT-5.3 Codex | Δ | Nova Pro |
|---|---|---|---|
| Agentic | GPT-5.3 Codex71.4 | MarginNo overlap | Nova ProNot measured |
| Coding | GPT-5.3 Codex67.2 | MarginNo overlap | Nova ProNot measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.3 Codex | Nova Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.3 Codex$1.75 input / $14 output | Nova ProNot available | A complete price comparison is not available. |
| Generation speedtokens per second | GPT-5.3 Codex79 tok/s | Nova Pro141 tok/s | Nova Pro has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-5.3 Codex88.26 s | Nova Pro0.81 s | Nova Pro reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-5.3 Codex400K | Nova Pro128K | GPT-5.3 Codex lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding5 benchmarks
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | GPT-5.3 Codex | Nova Pro | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 44.3% | 7.7% | GPT-5.3 Codex leads |
| AA-GPQA DiamondSource | 91.5% | 49.9% | GPT-5.3 Codex leads |
| AA-HLESource | 39.9% | 3.4% | GPT-5.3 Codex leads |
| AA-Omniscience IndexSource | 9.9% | -47.6% | GPT-5.3 Codex leads |
| AA-Omniscience AccuracySource | 51.8% | 17.0% | GPT-5.3 Codex leads |
| AA-Omniscience Hallucination RateSource | 86.9% | 77.9% | Nova Pro leads |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-5.3 Codex | Nova Pro | Result |
|---|---|---|---|
| AA-IFBenchSource | 75.4% | 38.1% | GPT-5.3 Codex leads |
Frequently Asked Questions (3)
Can I compare GPT-5.3 Codex and Nova Pro on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for GPT-5.3 Codex and Nova Pro today?
GPT-5.3 Codex: $1.75 input / $14.00 output per 1M tokens Nova Pro: Pricing unavailable Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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