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Model compare

GPT-4 vs GPT-5.1

The readout for GPT-4 and GPT-5.1, before the detailed comparison sheet.

Model A

GPT-4

OpenAI

Contender
vs

Model B

GPT-5.1

OpenAI

Leading

Key Takeaways

Weighted outcome: GPT-5.1. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.

Decision read

GPT-5.1

GPT-5.1 has the higher weighted result; Model A / B score 30.7 to 69.3.

Evidence depth

75 data points

Includes 5 benchmark rows, 0 audit samples, and 10 provider examples.

Selection signal

Start with GPT-5.1

The charts below split 15 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 GPT-4 and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Model compare
GPT-4
GPT-5.1
Overall leaderContenderLeading
Weighted overall score30.7 pts69.3 pts
Benchmark category leads1 categories2 categories
Operational advantagesFirst-token latencyCheapest input price, Average speed, Free providers, Provider coverage
Context window8.2K tokens400K tokens
Max output4.1K tokens128K tokens
Modalities

Input

Text

Output

Text

Input

ImageTextFile

Output

Text
Features
Text inputText outputTool callingStructured outputsJSON mode
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
GPT-4
GPT-5.1
DeveloperOpenAIOpenAI
ReleasedMay 2023Nov 2025
ParametersNo dataNo data
TokenizerGPTGPT
Knowledge cutoff2021-09-30No data
OpenRouter IDopenai/gpt-4openai/gpt-5.1
ReferencesNo dataNo data

When to choose each model

This report only uses LMSpeed data for GPT-4 and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

GPT-4

GPT-4 is stronger in benchmark categories (Coding) and operational dimensions (First-token latency).

GPT-5.1

GPT-5.1 is stronger in benchmark categories (Reasoning, Math) and operational dimensions (Cheapest input price, Average speed, 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
3 / 8
Model B coverage
6 / 8
Shared
3 shared categories

Avg. score

GPT-4

42.4

Avg. score

GPT-5.1

51.9

Agents

GPT-5.1

GPT-4-
GPT-5.147.7

Coding

GPT-4 leads by 0.4

GPT-449.5
GPT-5.149.1

Reasoning

GPT-5.1 leads by 17.1

GPT-436.9
GPT-5.154

Knowledge

GPT-5.1

GPT-4-
GPT-5.153

Math

GPT-5.1 leads by 13.3

GPT-440.7
GPT-5.154

Multilingual

No data

GPT-4-
GPT-5.1-

Multimodal

No data

GPT-4-
GPT-5.1-

Instruction following

GPT-5.1

GPT-4-
GPT-5.153.5

Professional benchmark details

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

Pricingverified

Input price

SourceGPT-4

GPT-4

$30.00/M

Rank #178/180 · confidence 4

+$28.75/M

GPT-5.1

winner

$1.25/M

Rank #119/180 · confidence 4

Pricingverified

Blended price

SourceGPT-4

GPT-4

$37.50/M

Rank #178/180 · confidence 4

+$34.06/M

GPT-5.1

winner

$3.44/M

Rank #135/180 · confidence 4

Pricingverified

Output price

SourceGPT-4

GPT-4

$60.00/M

Rank #173/180 · confidence 4

+$50.00/M

GPT-5.1

winner

$10.00/M

Rank #138/180 · confidence 4

Reasoningverified

GPQA

SourceGPT-4

GPT-4

34.9%

Rank #205/212 · confidence 4

+52.4%

GPT-5.1

winner

87.3%

Rank #48/212 · confidence 4

Reasoningverified

MMLU-Pro

SourceGPT-4

GPT-4

56.2%

Rank #121/129 · confidence 4

+23.9%

GPT-5.1

winner

80.1%

Rank #62/129 · confidence 4

API audit comparison

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

Provider
GPT-4
GPT-5.1
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
GPT-4
GPT-5.1
BUZZ10 tests

GPT-4

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

137 tok/s / 3299ms

input / output

No data

N1N5 tests

GPT-4

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

96 tok/s / 1862ms

input / output

No data

42公益站0 tests

GPT-4

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

AASS API0 tests

GPT-4

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

AI API0 tests

GPT-4

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

兔子API

GPT-4

gpt-4

speed / latency

No data

input / output

$0/request

GPT-5.1

gpt-5.1-chat-latest

speed / latency

No data

input / output

$0/request

Yun API

GPT-4

gpt-4-all

speed / latency

No data

input / output

$0.021/request

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.0027/request

KFCV50

GPT-4

gpt-4-all

speed / latency

No data

input / output

$0.014/request

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.0068/request

Newagiai

GPT-4

gpt-4-all

speed / latency

No data

input / output

$0.011/request

GPT-5.1

gpt-5.1-all

speed / latency

No data

input / output

$0.137/M/$1.10/M

柏拉图AI

GPT-4

gpt-4-all

speed / latency

No data

input / output

$0.011/request

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.137/M/$1.10/M

FAQ

Weighted outcome: GPT-5.1. 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.