Model comparison
GPT-5.4 Pro vs GPT-5.5 Pro
Head-to-head evidence from 7 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.4 Pro #44 (Estimated); GPT-5.5 Pro #38 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.4 Pro and GPT-5.5 Pro share 7 comparable benchmark results. 3 of 8 categories are comparable. 5 results are unique to GPT-5.4 Pro; 0 to GPT-5.5 Pro.
Updated July 22, 2026- Shared results
- 7
- GPT-5.4 Pro only
- 5
- GPT-5.5 Pro only
- 0
- Comparable categories
- 3 / 8
Pick GPT-5.5 Pro if you want the stronger benchmark profile. GPT-5.4 Pro only becomes the better choice if knowledge is the priority or you need the larger 1.05M context window.
Confidence note. This is a partial-evidence comparison with 7 shared benchmark results across 4 evidence categories; 3 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.5 Pro has the cleaner BenchAlign overall profile here, landing at 63.69 versus 60.89. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
GPT-5.5 Pro's sharpest advantage is in mathematics, where it averages 48.1 against 46.9. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 37.500% to 39.600%. GPT-5.4 Pro does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
GPT-5.4 Pro gives you the larger context window at 1.05M, compared with 1M for GPT-5.5 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-5.4 Pro | Δ | GPT-5.5 Pro |
|---|---|---|---|
| Knowledge | GPT-5.4 Pro58.7 | Margin← 1.5 | GPT-5.5 Pro57.2 |
| Math | GPT-5.4 Pro46.9 | Margin→ 1.2 | GPT-5.5 Pro48.1 |
| Agentic | GPT-5.4 Pro89.3 | Margin→ 0.8 | GPT-5.5 Pro90.1 |
| Reasoning | GPT-5.4 Pro83.3 | MarginNo overlap | GPT-5.5 ProNot measured |
| Multimodal | GPT-5.4 Pro94.0 | MarginNo overlap | GPT-5.5 ProNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tier 4)
MathA 37.500%B 39.600%Winner: GPT-5.5 ProΔ 2.1FrontierMath v2 (Tier 4): GPT-5.4 Pro scored 37.500%; GPT-5.5 Pro scored 39.600%. GPT-5.5 Pro wins this benchmark. - Source ↗
HLE
KnowledgeA 58.7%B 57.2%Winner: GPT-5.4 ProΔ 1.5HLE: GPT-5.4 Pro scored 58.7%; GPT-5.5 Pro scored 57.2%. GPT-5.4 Pro wins this benchmark. - Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 50.000%B 51.000%Winner: GPT-5.5 ProΔ 1FrontierMath v2 (Tiers 1-3): GPT-5.4 Pro scored 50.000%; GPT-5.5 Pro scored 51.000%. GPT-5.5 Pro wins this benchmark. - Source ↗
BrowseComp
AgenticA 89.3%B 90.1%Winner: GPT-5.5 ProΔ 0.8BrowseComp: GPT-5.4 Pro scored 89.3%; GPT-5.5 Pro scored 90.1%. GPT-5.5 Pro wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.4 Pro | GPT-5.5 Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.4 Pro$30 input / $180 output | GPT-5.5 Pro$30 input / $180 output | Listed prices are equal. |
| Generation speedtokens per second | GPT-5.4 Pro74 tok/s | GPT-5.5 ProNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.4 Pro151.79 s | GPT-5.5 ProNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.4 Pro1.05M | GPT-5.5 Pro1M | GPT-5.4 Pro lists the larger context window. |
Benchmark Deep Dive
Frequently Asked Questions (4)
Which is better, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.5 Pro is ahead on BenchLM's BenchAlign leaderboard, 63.69 to 60.89. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 37.500% and 39.600%.
Which is better for knowledge tasks, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.4 Pro has the edge for knowledge tasks in this comparison, averaging 58.7 versus 57.2. Inside this category, HLE is the benchmark that creates the most daylight between them.
Which is better for math, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for math in this comparison, averaging 48.1 versus 46.9. Inside this category, FrontierMath (legacy) is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for agentic tasks in this comparison, averaging 90.1 versus 89.3. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.
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