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Gemini 2.5 Flash vs GPT-5.4

The readout for Gemini 2.5 Flash and GPT-5.4, before the detailed comparison sheet.

Model A

Gemini 2.5 Flash

Google

Contender
vs

Model B

GPT-5.4

OpenAI

Leading

Key Takeaways

Weighted outcome: GPT-5.4. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.

Decision read

GPT-5.4

GPT-5.4 has the higher weighted result; Model A / B score 4 to 96.

Evidence depth

107 data points

Includes 21 benchmark rows, 0 audit samples, and 10 provider examples.

Selection signal

Start with GPT-5.4

The charts below split 31 high-signal samples across speed, scores, and audit health.

Change comparison

Switch either side of this report to compare another model with the same LMSpeed data pipeline.

Select a different model to open a new comparison URL.

Comparison sheet

This report only uses LMSpeed data for Gemini 2.5 Flash and GPT-5.4: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Model compare
Gemini 2.5 Flash
GPT-5.4
Overall leaderContenderLeading
Weighted overall score4.0 pts96.0 pts
Benchmark category leads0 categories6 categories
Operational advantagesAverage speedCheapest input price, First-token latency, Free providers, Provider coverage
Context window1.0M tokens1.1M tokens
Max output65.5K tokens128K tokens
Modalities

Input

FileImageTextAudiovideo

Output

Text

Input

TextImageFile

Output

Text
Features
Text inputImage inputFile inputAudio inputText outputTool callingStructured outputsJSON modeReasoning
Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning

The overall result weights benchmark capability categories at 80% and price, API speed/latency, and availability at 20%. Recent test volume does not affect the winner, and missing benchmark categories are excluded.

Model metadata

Model compare
Gemini 2.5 Flash
GPT-5.4
DeveloperGoogleOpenAI
ReleasedJun 2025Mar 2026
ParametersNo dataNo data
TokenizerGeminiGPT
Knowledge cutoff2025-01-31No data
OpenRouter IDgoogle/gemini-2.5-flashopenai/gpt-5.4
ReferencesNo dataNo data

When to choose each model

This report only uses LMSpeed data for Gemini 2.5 Flash and GPT-5.4: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Gemini 2.5 Flash

Gemini 2.5 Flash has these operational advantages: Average speed.

GPT-5.4

GPT-5.4 is stronger in benchmark categories (Agents, Coding, Reasoning, Knowledge, Math) and operational dimensions (Cheapest input price, First-token latency, Free providers, Provider coverage).

Benchmark score comparison

Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.

Category performance

Compare benchmark category scores on a 0-100 scale. Select a category to inspect the gap.

Model A coverage
6 / 8
Model B coverage
7 / 8
Shared
6 shared categories

Avg. score

Gemini 2.5 Flash

43.8

Avg. score

GPT-5.4

56.6

Agents

GPT-5.4 leads by 20.4

Gemini 2.5 Flash35.9
GPT-5.456.3

Coding

GPT-5.4 leads by 18.6

Gemini 2.5 Flash43.6
GPT-5.462.2

Reasoning

GPT-5.4 leads by 7.1

Gemini 2.5 Flash48.6
GPT-5.455.7

Knowledge

GPT-5.4 leads by 17.8

Gemini 2.5 Flash40.7
GPT-5.458.5

Math

GPT-5.4 leads by 6.2

Gemini 2.5 Flash50.6
GPT-5.456.8

Multilingual

No data

Gemini 2.5 Flash-
GPT-5.4-

Multimodal

GPT-5.4

Gemini 2.5 Flash-
GPT-5.452.5

Instruction following

GPT-5.4 leads by 10.8

Gemini 2.5 Flash43.2
GPT-5.454

Professional benchmark details

Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.

Aggregatereported

BenchLM overall score

SourceGemini 2.5 Flash

Gemini 2.5 Flash

45.0

Rank #95/112 · confidence 1 · eval date 2025-06-17

+18.0

GPT-5.4

winner

63.0

Rank #41/112 · confidence 4 · eval date 2026-03-05

Pricingverified

Input price

SourceGemini 2.5 Flash (Reasoning)

Gemini 2.5 Flash

winner

$0.300/M

Rank #55/186 · confidence 4

+$2.20/M

GPT-5.4

$2.50/M

Rank #154/186 · confidence 4

Pricingverified

Blended price

SourceGemini 2.5 Flash (Reasoning)

Gemini 2.5 Flash

winner

$0.850/M

Rank #82/186 · confidence 4

+$4.78/M

GPT-5.4

$5.63/M

Rank #158/186 · confidence 4

Pricingverified

Output price

SourceGemini 2.5 Flash (Reasoning)

Gemini 2.5 Flash

winner

$2.50/M

Rank #89/186 · confidence 4

+$12.50/M

GPT-5.4

$15.00/M

Rank #159/186 · confidence 4

Reasoningreported

CritPt

SourceGemini 2.5 Flash

Gemini 2.5 Flash

1.4

Rank #65/88 · confidence 1 · eval date 2025-06-17

+22.0

GPT-5.4

winner

23.4

Rank #11/88 · confidence 4 · eval date 2026-03-05

Reasoningreported

AA-LCR

SourceGemini 2.5 Flash

Gemini 2.5 Flash

48.0

Rank #89/106 · confidence 1 · eval date 2025-06-17

+34.0

GPT-5.4

winner

82.0

Rank #14/106 · confidence 4 · eval date 2026-03-05

Reasoningverified

GPQA

SourceGemini 2.5 Flash (Reasoning)

Gemini 2.5 Flash

winner

79.0%

Rank #100/218 · confidence 4

+4.2%

GPT-5.4

74.8%

Rank #122/218 · confidence 4

Reasoningverified

HLE

SourceGemini 2.5 Flash (Reasoning)

Gemini 2.5 Flash

winner

12.1%

Rank #113/216 · confidence 4

+0.8%

GPT-5.4

11.3%

Rank #116/216 · confidence 4

Codingreported

AA-SciCode

SourceGemini 2.5 Flash

Gemini 2.5 Flash

29.1

Rank #104/113 · confidence 1 · eval date 2025-06-17

+27.5

GPT-5.4

winner

56.6

Rank #10/113 · confidence 4 · eval date 2026-03-05

Mathreported

FrontierMath v2 (Tiers 1-3)

SourceGemini 2.5 Flash

Gemini 2.5 Flash

4.8

Rank #38/47 · confidence 1 · eval date 2025-06-17

+42.8

GPT-5.4

winner

47.6

Rank #7/47 · confidence 4 · eval date 2026-03-05

Mathreported

FrontierMath v2 (Tier 4)

SourceGemini 2.5 Flash

Gemini 2.5 Flash

4.2

Rank #24/36 · confidence 1 · eval date 2025-06-17

+22.9

GPT-5.4

winner

27.1

Rank #9/36 · confidence 4 · eval date 2026-03-05

Mathreported

BenchLM Math score

SourceGemini 2.5 Flash

Gemini 2.5 Flash

28.9

Rank #51/63 · confidence 1 · eval date 2025-06-17

+35.6

GPT-5.4

winner

64.5

Rank #24/63 · confidence 4 · eval date 2026-03-05

Knowledgereported

AA-Omniscience Hallucination Rate

SourceGemini 2.5 Flash

Gemini 2.5 Flash

winner

93.0

Rank #6/106 · confidence 1 · eval date 2025-06-17

+1.3

GPT-5.4

91.7

Rank #13/106 · confidence 4 · eval date 2026-03-05

Knowledgereported

AA-HLE

SourceGemini 2.5 Flash

Gemini 2.5 Flash

4.7

Rank #98/114 · confidence 1 · eval date 2025-06-17

+39.0

GPT-5.4

winner

43.7

Rank #15/114 · confidence 4 · eval date 2026-03-05

Knowledgereported

AA-Omniscience Accuracy

SourceGemini 2.5 Flash

Gemini 2.5 Flash

26.1

Rank #67/106 · confidence 1 · eval date 2025-06-17

+24.7

GPT-5.4

winner

50.8

Rank #15/106 · confidence 4 · eval date 2026-03-05

Knowledgereported

AA-GPQA Diamond

SourceGemini 2.5 Flash

Gemini 2.5 Flash

68.3

Rank #92/113 · confidence 1 · eval date 2025-06-17

+23.7

GPT-5.4

winner

92.0

Rank #21/113 · confidence 4 · eval date 2026-03-05

Knowledgereported

Artificial Analysis Intelligence Index

SourceGemini 2.5 Flash

Gemini 2.5 Flash

14.2

Rank #102/117 · confidence 1 · eval date 2025-06-17

+24.8

GPT-5.4

winner

39.0

Rank #29/117 · confidence 4 · eval date 2026-03-05

Multimodalreported

AA-MMMU-Pro

SourceGemini 2.5 Flash

Gemini 2.5 Flash

65.5

Rank #52/68 · confidence 1 · eval date 2025-06-17

+12.9

GPT-5.4

winner

78.4

Rank #23/68 · confidence 4 · eval date 2026-03-05

Multimodalreported

Design Arena Website

SourceGemini 2.5 Flash

Gemini 2.5 Flash

1127.0

Rank #67/78 · confidence 1 · eval date 2025-06-17

+105.0

GPT-5.4

winner

1232.0

Rank #42/78 · confidence 4 · eval date 2026-03-05

Instruction followingreported

AA-IFBench

SourceGemini 2.5 Flash

Gemini 2.5 Flash

39.0

Rank #72/84 · confidence 1 · eval date 2025-06-17

+34.9

GPT-5.4

winner

73.9

Rank #21/84 · confidence 4 · eval date 2026-03-05

Agentsreported

τ²-bench results

SourceGemini 2.5 Flash

Gemini 2.5 Flash

14.9

Rank #82/82 · confidence 1 · eval date 2025-06-17

+84.0

GPT-5.4

winner

98.9

Rank #2/82 · confidence 4 · eval date 2026-03-05

API audit comparison

Latest completed audits from shared providers, with four safety and integrity score groups plus report links.

Provider
Gemini 2.5 Flash
GPT-5.4
No completed audits are available from shared providers yet.

Provider examples

Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.

Provider
Gemini 2.5 Flash
GPT-5.4
天宫造物50 tests

Gemini 2.5 Flash

speed / latency

N/A / N/A

input / output

No data

GPT-5.4

speed / latency

50 tok/s / 7305ms

input / output

No data

SWT-API25 tests

Gemini 2.5 Flash

speed / latency

139 tok/s / 4002ms

input / output

No data

GPT-5.4

speed / latency

N/A / N/A

input / output

No data

0CHAT10 tests

Gemini 2.5 Flash

speed / latency

N/A / N/A

input / output

No data

GPT-5.4

speed / latency

51 tok/s / 2526ms

input / output

No data

CatClaw API10 tests

Gemini 2.5 Flash

speed / latency

54 tok/s / 10365ms

input / output

No data

GPT-5.4

speed / latency

N/A / N/A

input / output

No data

Omini Api10 tests

Gemini 2.5 Flash

speed / latency

N/A / N/A

input / output

No data

GPT-5.4

speed / latency

51 tok/s / 1443ms

input / output

No data

180txt API

Gemini 2.5 Flash

gemini-2.5-flash

speed / latency

No data

input / output

$0.105/M/$0.875/M

GPT-5.4

gpt-5.4-2026-03-05

speed / latency

No data

input / output

$0/M/$0/M

APIMart

Gemini 2.5 Flash

gemini-2.5-flash

speed / latency

No data

input / output

$0.230/M/$1.92/M

GPT-5.4

gpt-5.4

speed / latency

No data

input / output

$0/M/$0/M

DeadlySignal API

Gemini 2.5 Flash

gemini-2.5-flash

speed / latency

No data

input / output

$0/M/$0/M

GPT-5.4

gpt-5.4

speed / latency

No data

input / output

$0/M/$0/M

兔子API

Gemini 2.5 Flash

gemini-2.5-flash-preview-05-20

speed / latency

No data

input / output

$0/request

GPT-5.4

gpt-5.4-2026-03-05

speed / latency

No data

input / output

$0/request

PoloAPI

Gemini 2.5 Flash

gemini-2.5-flash-c

speed / latency

No data

input / output

$0.0027/request

GPT-5.4

gpt-5.4-openai-compact

speed / latency

No data

input / output

$0.514/M/$3.08/M

FAQ

Weighted outcome: GPT-5.4. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.

Why is this comparison indexable?
It has 6 verifiable comparison points, and both models have pricing or benchmark data.
Are missing metrics invented?
No. Metrics without LMSpeed data are omitted from this report.

Rankings are based on community-submitted tests and periodic health probes. Advisory only, not official data.