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DeepSeek V4 Flash vs GPT-5.4

The readout for DeepSeek V4 Flash and GPT-5.4, before the detailed comparison sheet.

Model A

DeepSeek V4 Flash

DeepSeek

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 8 to 92.

Evidence depth

103 data points

Includes 19 benchmark rows, 0 audit samples, and 10 provider examples.

Selection signal

Start with GPT-5.4

The charts below split 29 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 DeepSeek V4 Flash and GPT-5.4: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Model compare
DeepSeek V4 Flash
GPT-5.4
Overall leaderContenderLeading
Weighted overall score8.0 pts92.0 pts
Benchmark category leads0 categories5 categories
Operational advantagesCheapest input price, Average speedFirst-token latency, Free providers, Provider coverage
Context window1.0M tokens1.1M tokens
Max output384K tokens128K tokens
Modalities

Input

Text

Output

Text

Input

TextImageFile

Output

Text
Features
Text 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
DeepSeek V4 Flash
GPT-5.4
DeveloperDeepSeekOpenAI
ReleasedApr 2026Mar 2026
ParametersNo dataNo data
TokenizerDeepSeekGPT
Knowledge cutoffNo dataNo data
OpenRouter IDdeepseek/deepseek-v4-flashopenai/gpt-5.4
ReferencesNo dataNo data

When to choose each model

This report only uses LMSpeed data for DeepSeek V4 Flash and GPT-5.4: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

DeepSeek V4 Flash

DeepSeek V4 Flash has these operational advantages: Cheapest input price, Average speed.

GPT-5.4

GPT-5.4 is stronger in benchmark categories (Agents, Coding, Reasoning, Knowledge, Math) and operational dimensions (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
5 / 8
Model B coverage
7 / 8
Shared
5 shared categories

Avg. score

DeepSeek V4 Flash

43.3

Avg. score

GPT-5.4

56.6

Agents

GPT-5.4 leads by 10.9

DeepSeek V4 Flash45.4
GPT-5.456.3

Coding

GPT-5.4 leads by 18.3

DeepSeek V4 Flash43.9
GPT-5.462.2

Reasoning

GPT-5.4 leads by 2.4

DeepSeek V4 Flash53.3
GPT-5.455.7

Knowledge

GPT-5.4 leads by 17.1

DeepSeek V4 Flash41.4
GPT-5.458.5

Math

GPT-5.4 leads by 24.2

DeepSeek V4 Flash32.6
GPT-5.456.8

Multilingual

No data

DeepSeek V4 Flash-
GPT-5.4-

Multimodal

GPT-5.4

DeepSeek V4 Flash-
GPT-5.452.5

Instruction following

GPT-5.4

DeepSeek V4 Flash-
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

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

51.0

Rank #78/111 · confidence 2 · eval date 2026-07-31

+12.0

GPT-5.4

winner

63.0

Rank #40/111 · confidence 4 · eval date 2026-03-05

Pricingverified

Output price

SourceDeepSeek V4 Flash (Reasoning, High Effort)

DeepSeek V4 Flash

winner

$0.280/M

Rank #10/186 · confidence 4

+$14.72/M

GPT-5.4

$15.00/M

Rank #159/186 · confidence 4

Pricingverified

Blended price

SourceDeepSeek V4 Flash (Reasoning, High Effort)

DeepSeek V4 Flash

winner

$0.168/M

Rank #13/186 · confidence 4

+$5.46/M

GPT-5.4

$5.63/M

Rank #158/186 · confidence 4

Pricingverified

Input price

SourceDeepSeek V4 Flash (Reasoning, High Effort)

DeepSeek V4 Flash

winner

$0.130/M

Rank #18/186 · confidence 4

+$2.37/M

GPT-5.4

$2.50/M

Rank #154/186 · confidence 4

Reasoningverified

HLE

SourceDeepSeek V4 Flash (Reasoning, High Effort)

DeepSeek V4 Flash

winner

30.3%

Rank #55/216 · confidence 4

+19.0%

GPT-5.4

11.3%

Rank #116/216 · confidence 4

Reasoningverified

GPQA

SourceDeepSeek V4 Flash (Reasoning, High Effort)

DeepSeek V4 Flash

winner

86.7%

Rank #56/218 · confidence 4

+11.9%

GPT-5.4

74.8%

Rank #122/218 · confidence 4

Codingreported

SWE-bench Pro

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

52.3

Rank #43/50 · confidence 2 · eval date 2026-07-31

+5.4

GPT-5.4

winner

57.7

Rank #21/50 · confidence 4 · eval date 2026-03-05

Codingreported

BenchLM Coding score

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

winner

46.0

Rank #65/87 · confidence 2 · eval date 2026-07-31

+3.2

GPT-5.4

42.8

Rank #69/87 · confidence 4 · eval date 2026-03-05

Mathreported

BenchLM Math score

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

winner

78.4

Rank #11/63 · confidence 2 · eval date 2026-07-31

+13.9

GPT-5.4

64.5

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

Knowledgereported

GPQA-D

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

87.4

Rank #26/32 · confidence 2 · eval date 2026-07-31

+5.4

GPT-5.4

winner

92.8

Rank #9/32 · confidence 4 · eval date 2026-03-05

Knowledgereported

BenchLM Knowledge score

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

52.8

Rank #69/83 · confidence 2 · eval date 2026-07-31

+21.5

GPT-5.4

winner

74.3

Rank #30/83 · confidence 4 · eval date 2026-03-05

Multimodalreported

Design Arena Website

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

1230.0

Rank #43/78 · confidence 2 · eval date 2026-07-31

+4.0

GPT-5.4

winner

1234.0

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

Agentsreported

Gert Labs

SourceDeepSeek V4 Flash

DeepSeek V4 Flash

54.4

Rank #18/49 · confidence 2 · eval date 2026-07-31

+10.5

GPT-5.4

winner

64.9

Rank #4/49 · confidence 4 · eval date 2026-03-05

Agentsreported

Toolathlon

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

43.5

Rank #16/24 · confidence 2 · eval date 2026-07-31

+11.1

GPT-5.4

winner

54.6

Rank #6/24 · confidence 4 · eval date 2026-03-05

Agentsreported

Claw-Eval

SourceDeepSeek V4 Flash

DeepSeek V4 Flash

57.8

Rank #16/27 · confidence 2 · eval date 2026-07-31

+2.5

GPT-5.4

winner

60.3

Rank #13/27 · confidence 4 · eval date 2026-03-05

Agentsreported

Terminal-Bench 2.0

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

56.6

Rank #38/53 · confidence 2 · eval date 2026-07-31

+18.5

GPT-5.4

winner

75.1

Rank #13/53 · confidence 4 · eval date 2026-03-05

Agentsreported

BrowseComp

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

53.5

Rank #31/32 · confidence 2 · eval date 2026-07-31

+29.2

GPT-5.4

winner

82.7

Rank #16/32 · confidence 4 · eval date 2026-03-05

Agentsreported

MCP Atlas

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

67.4

Rank #21/31 · confidence 2 · eval date 2026-07-31

+3.2

GPT-5.4

winner

70.6

Rank #19/31 · confidence 4 · eval date 2026-03-05

Agentsreported

BenchLM Agentic score

SourceDeepSeek V4 Flash (High)

DeepSeek V4 Flash

34.6

Rank #64/76 · confidence 2 · eval date 2026-07-31

+37.4

GPT-5.4

winner

72.0

Rank #28/76 · 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
DeepSeek V4 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
DeepSeek V4 Flash
GPT-5.4
OpenCode210 tests

DeepSeek V4 Flash

speed / latency

81 tok/s / 12508ms

input / output

No data

GPT-5.4

speed / latency

N/A / N/A

input / output

No data

Mars HK125 tests

DeepSeek V4 Flash

speed / latency

N/A / N/A

input / output

No data

GPT-5.4

speed / latency

49 tok/s / 6084ms

input / output

No data

Jasper45 tests

DeepSeek V4 Flash

speed / latency

96 tok/s / 7428ms

input / output

No data

GPT-5.4

speed / latency

N/A / N/A

input / output

No data

Sub2API30 tests

DeepSeek V4 Flash

speed / latency

49 tok/s / 5413ms

input / output

No data

GPT-5.4

speed / latency

51 tok/s / 4032ms

input / output

No data

小水管 API25 tests

DeepSeek V4 Flash

speed / latency

83 tok/s / 5114ms

input / output

No data

GPT-5.4

speed / latency

44 tok/s / 2518ms

input / output

No data

APIMart

DeepSeek V4 Flash

deepseek-v4-flash

speed / latency

No data

input / output

$0.110/M/$0.219/M

GPT-5.4

gpt-5.4

speed / latency

No data

input / output

$0/M/$0/M

DeadlySignal API

DeepSeek V4 Flash

deepseek-ai/deepseek-v4-flash-0731

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

Dext API

DeepSeek V4 Flash

deepseek-v4-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

S3AI API

DeepSeek V4 Flash

deepseek-ai/deepseek-v4-flash-0731

speed / latency

No data

input / output

$0/request

GPT-5.4

gpt-5.4

speed / latency

No data

input / output

$0.309/M/$1.86/M

WSocket AI

DeepSeek V4 Flash

deepseek-v4-flash-free

speed / latency

No data

input / output

$0/M/$0/M

GPT-5.4

gpt-5.4

speed / latency

No data

input / output

$74.25/M/$445.50/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.