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Model comparison

GPT-5.5 Pro vs o4-mini (high)

Data verified

Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.

63.69/100
Margin
13.7pts
← winning
49.98/100
1 category wins0 category wins

Public leaderboard positions: GPT-5.5 Pro #38 (Estimated); o4-mini (high) #118 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.5 Pro and o4-mini (high) share 2 comparable benchmark results. 1 of 8 categories are comparable. 5 results are unique to GPT-5.5 Pro; 0 to o4-mini (high).

Updated July 22, 2026
Shared results
2
GPT-5.5 Pro only
5
o4-mini (high) only
0
Comparable categories
1 / 8

Pick GPT-5.5 Pro if you want the stronger benchmark profile. o4-mini (high) only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.

Confidence note. This is a partial-evidence comparison with 2 shared benchmark results 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-5.5 Pro is clearly ahead on the BenchAlign aggregate, 63.69 to 49.98. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.5 Pro's sharpest advantage is in mathematics, where it averages 48.1 against 20.2. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 39.600% to 6.250%.

GPT-5.5 Pro gives you the larger context window at 1M, compared with 200K for o4-mini (high).

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 scores and score margins for GPT-5.5 Pro and o4-mini (high)
CategoryGPT-5.5 ProΔo4-mini (high)
MathGPT-5.5 Pro48.1Margin 27.9o4-mini (high)20.2
AgenticGPT-5.5 Pro90.1MarginNo overlapo4-mini (high)Not measured
KnowledgeGPT-5.5 Pro57.2MarginNo overlapo4-mini (high)Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · GPT-5.5 ProB · o4-mini (high)
  1. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 39.600%B 6.250%
    Winner: GPT-5.5 ProΔ 33.4
    FrontierMath v2 (Tier 4): GPT-5.5 Pro scored 39.600%; o4-mini (high) scored 6.250%. GPT-5.5 Pro wins this benchmark.
  2. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 51.000%B 24.828%
    Winner: GPT-5.5 ProΔ 26.2
    FrontierMath v2 (Tiers 1-3): GPT-5.5 Pro scored 51.000%; o4-mini (high) scored 24.828%. GPT-5.5 Pro wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricGPT-5.5 Proo4-mini (high)Comparison
Input / output priceUSD per 1M tokensGPT-5.5 Pro$30 input / $180 outputo4-mini (high)Not availableA complete price comparison is not available.
Generation speedtokens per secondGPT-5.5 ProNot availableo4-mini (high)161 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.5 ProNot availableo4-mini (high)21.94 sA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.5 Pro1Mo4-mini (high)200KGPT-5.5 Pro lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-5.5 Proo4-mini (high)Result
BrowseCompSource 90.1%Not comparable
Reasoning
BenchmarkGPT-5.5 Proo4-mini (high)Result
CritPtSource 30.6%Not comparable
Knowledge
BenchmarkGPT-5.5 Proo4-mini (high)Result
HLESource 57.2%Not comparable
HLE w/o toolsSource 43.1%Not comparable
MathGPT-5.5 Pro wins
BenchmarkGPT-5.5 Proo4-mini (high)Result
FrontierMath (legacy)Source 52.4%Not comparable
FrontierMath v2 (Tiers 1-3)Source 51.000%24.828%GPT-5.5 Pro leads
FrontierMath v2 (Tier 4)Source 39.600%6.250%GPT-5.5 Pro leads
Frequently Asked Questions (2)

Which is better, GPT-5.5 Pro or o4-mini (high)?

GPT-5.5 Pro is ahead on BenchLM's BenchAlign leaderboard, 63.69 to 49.98. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 39.600% and 6.250%.

Which is better for math, GPT-5.5 Pro or o4-mini (high)?

GPT-5.5 Pro has the edge for math in this comparison, averaging 48.1 versus 20.2. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

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Last updated: July 22, 2026

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