Model comparison
GPT-5.3 Codex vs GPT-5.4 Pro
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.3 Codex #26 (Supported); GPT-5.4 Pro #44 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.3 Codex and GPT-5.4 Pro share 1 comparable benchmark result. 1 of 8 categories are comparable. 20 results are unique to GPT-5.3 Codex; 11 to GPT-5.4 Pro.
Updated July 23, 2026- Shared results
- 1
- GPT-5.3 Codex only
- 20
- GPT-5.4 Pro only
- 11
- Comparable categories
- 1 / 8
Pick GPT-5.3 Codex if you want the stronger benchmark profile. GPT-5.4 Pro only becomes the better choice if agentic is the priority or you need the larger 1.05M context window.
Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.3 Codex is clearly ahead on the BenchAlign aggregate, 66.69 to 60.89. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.4 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $1.75 input / $14.00 output per 1M tokens for GPT-5.3 Codex. That is roughly 12.9x on output cost alone. GPT-5.4 Pro gives you the larger context window at 1.05M, compared with 400K for GPT-5.3 Codex.
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 | GPT-5.4 Pro |
|---|---|---|---|
| Agentic | GPT-5.3 Codex71.4 | Margin→ 17.9 | GPT-5.4 Pro89.3 |
| Coding | GPT-5.3 Codex67.2 | MarginNo overlap | GPT-5.4 ProNot measured |
| Reasoning | GPT-5.3 CodexNot measured | MarginNo overlap | GPT-5.4 Pro83.3 |
| Knowledge | GPT-5.3 CodexNot measured | MarginNo overlap | GPT-5.4 Pro58.7 |
| Math | GPT-5.3 CodexNot measured | MarginNo overlap | GPT-5.4 Pro46.9 |
| Multimodal | GPT-5.3 CodexNot measured | MarginNo overlap | GPT-5.4 Pro94.0 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.3 Codex | GPT-5.4 Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.3 Codex$1.75 input / $14 output | GPT-5.4 Pro$30 input / $180 output | GPT-5.3 Codex has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.3 Codex79 tok/s | GPT-5.4 Pro74 tok/s | GPT-5.3 Codex has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-5.3 Codex88.26 s | GPT-5.4 Pro151.79 s | GPT-5.3 Codex reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-5.3 Codex400K | GPT-5.4 Pro1.05M | GPT-5.4 Pro lists the larger context window. |
Benchmark Deep Dive
AgenticGPT-5.4 Pro wins6 benchmarks
Coding5 benchmarks
Reasoning3 benchmarks
Knowledge10 benchmarks
| Benchmark | GPT-5.3 Codex | GPT-5.4 Pro | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 44.3% | — | Not comparable |
| AA-GPQA DiamondSource | 91.5% | — | Not comparable |
| AA-HLESource | 39.9% | — | Not comparable |
| AA-Omniscience IndexSource | 9.9% | — | Not comparable |
| AA-Omniscience AccuracySource | 51.8% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 86.9% | — | Not comparable |
| HLESource | — | 58.7% | Not comparable |
| FrontierScienceSource | — | 36.7% | Not comparable |
| FrontierScience ResearchSource | — | 36.7% | Not comparable |
| HLE w/o toolsSource | — | 42.7% | Not comparable |
Math4 benchmarks
Multimodal3 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-5.3 Codex | GPT-5.4 Pro | Result |
|---|---|---|---|
| AA-IFBenchSource | 75.4% | — | Not comparable |
Frequently Asked Questions (2)
Which is better, GPT-5.3 Codex or GPT-5.4 Pro?
GPT-5.3 Codex is ahead on BenchLM's BenchAlign leaderboard, 66.69 to 60.89.
Which is better for agentic tasks, GPT-5.3 Codex or GPT-5.4 Pro?
GPT-5.4 Pro has the edge for agentic tasks in this comparison, averaging 89.3 versus 71.4. GPT-5.3 Codex stays close enough that the answer can still flip depending on your workload.
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