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Model comparison

Gemini 3.5 Flash vs GPT-5.4 Pro

Data verified

Head-to-head evidence from 6 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

64.75/100
Margin
3.9pts
← winning
60.89/100
0 category wins5 category wins

Public leaderboard positions: Gemini 3.5 Flash #33 (Estimated); GPT-5.4 Pro #44 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Gemini 3.5 Flash and GPT-5.4 Pro share 6 comparable benchmark results. 5 of 8 categories are comparable. 40 results are unique to Gemini 3.5 Flash; 6 to GPT-5.4 Pro.

Updated July 23, 2026
Shared results
6
Gemini 3.5 Flash only
40
GPT-5.4 Pro only
6
Comparable categories
5 / 8

Pick Gemini 3.5 Flash if you want the stronger benchmark profile. GPT-5.4 Pro only becomes the better choice if mathematics is the priority or you need the larger 1.05M context window.

Confidence note. This is a partial-evidence comparison with 6 shared benchmark results across 4 evidence categories; 5 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Gemini 3.5 Flash is clearly ahead on the BenchAlign aggregate, 64.75 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 $1.50 input / $9.00 output per 1M tokens for Gemini 3.5 Flash. That is roughly 20.0x on output cost alone. GPT-5.4 Pro gives you the larger context window at 1.05M, compared with 1M for Gemini 3.5 Flash.

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 Gemini 3.5 Flash and GPT-5.4 Pro
CategoryGemini 3.5 FlashΔGPT-5.4 Pro
MathGemini 3.5 Flash32.9Margin→ 14.0GPT-5.4 Pro46.9
AgenticGemini 3.5 Flash77.2Margin→ 12.1GPT-5.4 Pro89.3
KnowledgeGemini 3.5 Flash47.2Margin→ 11.5GPT-5.4 Pro58.7
MultimodalGemini 3.5 Flash83.8Margin→ 10.2GPT-5.4 Pro94.0
ReasoningGemini 3.5 Flash74.7Margin→ 8.6GPT-5.4 Pro83.3
CodingGemini 3.5 Flash53.9MarginNo overlapGPT-5.4 ProNot measured
Inst. FollowingGemini 3.5 Flash76.3MarginNo overlapGPT-5.4 ProNot measured

Decisive benchmark drivers

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

More
A · Gemini 3.5 FlashB · GPT-5.4 Pro

  1. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 14.583%B 37.500%
    Winner: GPT-5.4 ProΔ 22.9
    FrontierMath v2 (Tier 4): Gemini 3.5 Flash scored 14.583%; GPT-5.4 Pro scored 37.500%. GPT-5.4 Pro wins this benchmark.

  2. HLE

    Knowledge
    Source ↗
    A 40.2%B 58.7%
    Winner: GPT-5.4 ProΔ 18.5
    HLE: Gemini 3.5 Flash scored 40.2%; GPT-5.4 Pro scored 58.7%. GPT-5.4 Pro wins this benchmark.

  3. ARC-AGI-2

    Reasoning
    Source ↗
    A 72.1%B 83.3%
    Winner: GPT-5.4 ProΔ 11.2
    ARC-AGI-2: Gemini 3.5 Flash scored 72.1%; GPT-5.4 Pro scored 83.3%. GPT-5.4 Pro wins this benchmark.

  4. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 38.966%B 50.000%
    Winner: GPT-5.4 ProΔ 11
    FrontierMath v2 (Tiers 1-3): Gemini 3.5 Flash scored 38.966%; GPT-5.4 Pro scored 50.000%. GPT-5.4 Pro wins this benchmark.

  5. MMMU-Pro

    Multimodal
    Source ↗
    A 83.6%B 94%
    Winner: GPT-5.4 ProΔ 10.4
    MMMU-Pro: Gemini 3.5 Flash scored 83.6%; GPT-5.4 Pro scored 94%. GPT-5.4 Pro wins this benchmark.

Operational comparison

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

MetricGemini 3.5 FlashGPT-5.4 ProComparison
Input / output priceUSD per 1M tokensGemini 3.5 Flash$1.5 input / $9 outputGPT-5.4 Pro$30 input / $180 outputGemini 3.5 Flash has the lower combined listed price.
Generation speedtokens per secondGemini 3.5 Flash284.2 tok/sGPT-5.4 Pro74 tok/sGemini 3.5 Flash has the higher measured throughput.
First-answer latencyseconds to first tokenGemini 3.5 Flash18.55 sGPT-5.4 Pro151.79 sGemini 3.5 Flash reaches the first token sooner.
Context windowmaximum listed tokensGemini 3.5 Flash1MGPT-5.4 Pro1.05MGPT-5.4 Pro lists the larger context window.

Benchmark Deep Dive

AgenticGPT-5.4 Pro wins
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
Terminal-Bench 2.0Source 76.2%—Not comparable
MCP AtlasSource 83.6%—Not comparable
ToolathlonSource 56.5%—Not comparable
OSWorld-VerifiedSource 78.4%—Not comparable
Finance Agent v2Source 57.9%—Not comparable
GDPval-AASource 1349—Not comparable
τ²-bench resultsSource 95.3%—Not comparable
GDPval-AASource 42.4%—Not comparable
AA Agentic IndexSource 37.5%—Not comparable
APEX-Agents-AASource 47.1%—Not comparable
Gert LabsSource 61.85%—Not comparable
ResearchClawBenchSource 18.0%—Not comparable
AA AutomationBenchSource 42.6%—Not comparable
AA EnterpriseOps-GymSource 50.1%—Not comparable
terminalBenchHardSource 40.9%—Not comparable
BrowseCompSource —89.3%Not comparable
Coding
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
Terminal-Bench 2.0Source 76.2%—Not comparable
SWE-bench ProSource 55.1%—Not comparable
SciCodeSource 53.1%—Not comparable
Vibe Code BenchSource 48.68%—Not comparable
cursorBench31Source 49.8%—Not comparable
cursorBench32Source 48.8%—Not comparable
AA Coding IndexSource 70.1%—Not comparable
AA-SciCodeSource 53.1%—Not comparable
ReasoningGPT-5.4 Pro wins
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
MRCRv2Source 77.3%—Not comparable
MRCR 1MSource 26.6%—Not comparable
ARC-AGI-2Source 72.1%83.3%GPT-5.4 Pro leads
AA-LCRSource 69.3%—Not comparable
CritPtSource 13.1%30.0%GPT-5.4 Pro leads
KnowledgeGPT-5.4 Pro wins
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
Artificial Analysis Intelligence IndexSource 50.2%—Not comparable
GPQASource 92.2%—Not comparable
GPQA-DSource 92.7%—Not comparable
HLESource 40.2%58.7%GPT-5.4 Pro leads
AA-Omniscience AccuracySource 51.9%—Not comparable
AA-Omniscience Hallucination RateSource 60.7%—Not comparable
AA-GPQA DiamondSource 92.2%—Not comparable
AA-HLESource 41.0%—Not comparable
AA-Omniscience IndexSource 22.7%—Not comparable
FrontierScienceSource —36.7%Not comparable
FrontierScience ResearchSource —36.7%Not comparable
HLE w/o toolsSource —42.7%Not comparable
MathGPT-5.4 Pro wins
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
FrontierMath v2 (Tiers 1-3)Source 38.966%50.000%GPT-5.4 Pro leads
FrontierMath v2 (Tier 4)Source 14.583%37.500%GPT-5.4 Pro leads
IPhO 2025 (Theory)Source —93.5%Not comparable
FrontierMath (legacy)Source —50%Not comparable
MultimodalGPT-5.4 Pro wins
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
CharXivSource 84.2%—Not comparable
MMMU-ProSource 83.6%94%GPT-5.4 Pro leads
Blueprint-Bench 2Source 33.6%—Not comparable
AA-MMMU-ProSource 84.3%—Not comparable
Design Arena WebsiteSource 1285—Not comparable
Inst. Following
BenchmarkGemini 3.5 FlashGPT-5.4 ProResult
IFBenchSource 76.3%—Not comparable
AA-IFBenchSource 76.3%—Not comparable
Frequently Asked Questions (6)

Which is better, Gemini 3.5 Flash or GPT-5.4 Pro?

Gemini 3.5 Flash is ahead on BenchLM's BenchAlign leaderboard, 64.75 to 60.89. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 14.583% and 37.500%.

Which is better for knowledge tasks, Gemini 3.5 Flash or GPT-5.4 Pro?

GPT-5.4 Pro has the edge for knowledge tasks in this comparison, averaging 58.7 versus 47.2. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for math, Gemini 3.5 Flash or GPT-5.4 Pro?

GPT-5.4 Pro has the edge for math in this comparison, averaging 46.9 versus 32.9. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

Which is better for reasoning, Gemini 3.5 Flash or GPT-5.4 Pro?

GPT-5.4 Pro has the edge for reasoning in this comparison, averaging 83.3 versus 74.7. Inside this category, CritPt is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Gemini 3.5 Flash or GPT-5.4 Pro?

GPT-5.4 Pro has the edge for agentic tasks in this comparison, averaging 89.3 versus 77.2. Gemini 3.5 Flash stays close enough that the answer can still flip depending on your workload.

Which is better for multimodal and grounded tasks, Gemini 3.5 Flash or GPT-5.4 Pro?

GPT-5.4 Pro has the edge for multimodal and grounded tasks in this comparison, averaging 94 versus 83.8. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

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Last updated: July 23, 2026

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