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Model compare

GPT-5.1 vs GPT-5 Nano

The readout for GPT-5.1 and GPT-5 Nano, before the detailed comparison sheet.

Model A

GPT-5.1

OpenAI

Leading
vs

Model B

GPT-5 Nano

OpenAI

Contender

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 69.3 to 30.7.

Evidence depth

81 data points

Includes 8 benchmark rows, 0 audit samples, and 9 provider examples.

Selection signal

Start with GPT-5.1

The charts below split 17 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-5.1 and GPT-5 Nano: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Model compare
GPT-5.1
GPT-5 Nano
Overall leaderLeadingContender
Weighted overall score69.3 pts30.7 pts
Benchmark category leads2 categories1 categories
Operational advantagesAverage speed, First-token latency, Free providers, Provider coverageCheapest input price
Context window400K tokens400K tokens
Max output128K tokens128K tokens
Modalities

Input

ImageTextFile

Output

Text

Input

TextImageFile

Output

Text
Features
Text inputImage inputFile 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
GPT-5.1
GPT-5 Nano
DeveloperOpenAIOpenAI
ReleasedNov 2025Aug 2025
ParametersNo dataNo data
TokenizerGPTGPT
Knowledge cutoffNo data2024-05-31
OpenRouter IDopenai/gpt-5.1openai/gpt-5-nano
ReferencesNo dataNo data

When to choose each model

This report only uses LMSpeed data for GPT-5.1 and GPT-5 Nano: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

GPT-5.1

GPT-5.1 is stronger in benchmark categories (Reasoning, Math) and operational dimensions (Average speed, First-token latency, Free providers, Provider coverage).

GPT-5 Nano

GPT-5 Nano is stronger in benchmark categories (Coding) and operational dimensions (Cheapest input price).

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
3 / 8
Shared
3 shared categories

Avg. score

GPT-5.1

51.8

Avg. score

GPT-5 Nano

49.9

Agents

GPT-5.1

GPT-5.147.7
GPT-5 Nano-

Coding

GPT-5 Nano leads by 1.9

GPT-5.149
GPT-5 Nano50.9

Reasoning

GPT-5.1 leads by 6.0

GPT-5.153.9
GPT-5 Nano47.9

Knowledge

GPT-5.1

GPT-5.152.9
GPT-5 Nano-

Math

GPT-5.1 leads by 3.1

GPT-5.154
GPT-5 Nano50.9

Multilingual

No data

GPT-5.1-
GPT-5 Nano-

Multimodal

No data

GPT-5.1-
GPT-5 Nano-

Instruction following

GPT-5.1

GPT-5.153.5
GPT-5 Nano-

Professional benchmark details

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

Pricingverified

Input price

SourceGPT-5.1 (high)

GPT-5.1

$1.25/M

Rank #121/184 · confidence 4

+$1.20/M

GPT-5 Nano

winner

$0.050/M

Rank #2/184 · confidence 4

Pricingverified

Blended price

SourceGPT-5.1 (high)

GPT-5.1

$3.44/M

Rank #138/184 · confidence 4

+$3.30/M

GPT-5 Nano

winner

$0.138/M

Rank #9/184 · confidence 4

Pricingverified

Output price

SourceGPT-5.1 (high)

GPT-5.1

$10.00/M

Rank #141/184 · confidence 4

+$9.60/M

GPT-5 Nano

winner

$0.400/M

Rank #15/184 · confidence 4

Reasoningverified

GPQA

SourceGPT-5.1 (high)

GPT-5.1

winner

87.3%

Rank #51/216 · confidence 4

+19.7%

GPT-5 Nano

67.6%

Rank #145/216 · confidence 4

Reasoningverified

HLE

SourceGPT-5.1 (high)

GPT-5.1

winner

28.5%

Rank #59/213 · confidence 4

+19.0%

GPT-5 Nano

9.5%

Rank #124/213 · confidence 4

Reasoningverified

MMLU-Pro

SourceGPT-5.1 (Non-reasoning)

GPT-5.1

winner

80.1%

Rank #62/129 · confidence 4

+2.1%

GPT-5 Nano

78.0%

Rank #74/129 · confidence 4

Codingverified

LiveCodeBench

SourceGPT-5.1 (high)

GPT-5.1

winner

86.8%

Rank #4/115 · confidence 4

+7.9%

GPT-5 Nano

78.9%

Rank #20/115 · confidence 4

Codingverified

SciCode

SourceGPT-5.1 (high)

GPT-5.1

winner

43.3%

Rank #59/209 · confidence 4

+6.7%

GPT-5 Nano

36.6%

Rank #119/209 · confidence 4

API audit comparison

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

Provider
GPT-5.1
GPT-5 Nano
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-5.1
GPT-5 Nano
BUZZ10 tests

GPT-5.1

speed / latency

137 tok/s / 3299ms

input / output

No data

GPT-5 Nano

speed / latency

N/A / N/A

input / output

No data

YUNWU API10 tests

GPT-5.1

gpt-5.1-chat-latest

speed / latency

N/A / N/A

input / output

$0.030/M/$0.240/M

GPT-5 Nano

gpt-5-nano-2025-08-07

speed / latency

102 tok/s / 12165ms

input / output

$0.0012/M/$0.0096/M

N1N5 tests

GPT-5.1

speed / latency

96 tok/s / 1862ms

input / output

No data

GPT-5 Nano

speed / latency

N/A / N/A

input / output

No data

OpenCode5 tests

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

GPT-5 Nano

speed / latency

105 tok/s / 6742ms

input / output

No data

10dian-API0 tests

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

GPT-5 Nano

speed / latency

N/A / N/A

input / output

No data

兔子API

GPT-5.1

gpt-5.1-chat-latest

speed / latency

No data

input / output

$0/request

GPT-5 Nano

gpt-5-nano

speed / latency

No data

input / output

$0/request

Zhongzhuan Chat

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.030/M/$0.240/M

GPT-5 Nano

gpt-5-nano

speed / latency

No data

input / output

$0.0012/M/$0.0096/M

向量引擎

GPT-5.1

gpt-5.1-chat

speed / latency

No data

input / output

$0.030/M/$0.240/M

GPT-5 Nano

gpt-5-nano

speed / latency

No data

input / output

$0.0012/M/$0.0096/M

SmokeDivine AI

GPT-5.1

gpt-5.1-2025-11-13

speed / latency

No data

input / output

$0.048/M/$0.384/M

GPT-5 Nano

gpt-5-nano

speed / latency

No data

input / output

$0.0019/M/$0.015/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.