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Model compare

Claude Opus 4.8 vs GPT-5.1

The readout for Claude Opus 4.8 and GPT-5.1, before the detailed comparison sheet.

Model A

Claude Opus 4.8

Anthropic

Leading
vs

Model B

GPT-5.1

OpenAI

Contender

Key Takeaways

Weighted outcome: Claude Opus 4.8. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.

Decision read

Claude Opus 4.8

Claude Opus 4.8 has the higher weighted result; Model A / B score 74.7 to 25.3.

Evidence depth

118 data points

Includes 27 benchmark rows, 0 audit samples, and 10 provider examples.

Selection signal

Start with Claude Opus 4.8

The charts below split 37 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 Claude Opus 4.8 and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Model compare
Claude Opus 4.8
GPT-5.1
Overall leaderLeadingContender
Weighted overall score74.7 pts25.3 pts
Benchmark category leads5 categories1 categories
Operational advantagesCheapest input price, Average speedFirst-token latency, Free providers, Provider coverage
Context window1M tokens400K tokens
Max output128K tokens128K tokens
Modalities

Input

TextImageFile

Output

Text

Input

ImageTextFile

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
Claude Opus 4.8
GPT-5.1
DeveloperAnthropicOpenAI
ReleasedMay 2026Nov 2025
ParametersNo dataNo data
TokenizerClaudeGPT
Knowledge cutoffNo dataNo data
OpenRouter IDanthropic/claude-opus-4.8openai/gpt-5.1
ReferencesNo dataNo data

When to choose each model

This report only uses LMSpeed data for Claude Opus 4.8 and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Claude Opus 4.8

Claude Opus 4.8 is stronger in benchmark categories (Agents, Coding, Reasoning, Knowledge, Math) and operational dimensions (Cheapest input price, Average speed).

GPT-5.1

GPT-5.1 is stronger in benchmark categories (Instruction following) 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
8 / 8
Model B coverage
6 / 8
Shared
6 shared categories

Avg. score

Claude Opus 4.8

58.8

Avg. score

GPT-5.1

51.9

Agents

Claude Opus 4.8 leads by 14.9

Claude Opus 4.862.6
GPT-5.147.7

Coding

Claude Opus 4.8 leads by 16.1

Claude Opus 4.865.2
GPT-5.149.1

Reasoning

Claude Opus 4.8 leads by 2.4

Claude Opus 4.856.4
GPT-5.154

Knowledge

Claude Opus 4.8 leads by 10.7

Claude Opus 4.863.7
GPT-5.153

Math

Claude Opus 4.8 leads by 4.0

Claude Opus 4.858
GPT-5.154

Multilingual

Claude Opus 4.8

Claude Opus 4.855
GPT-5.1-

Multimodal

Claude Opus 4.8

Claude Opus 4.859.6
GPT-5.1-

Instruction following

GPT-5.1 leads by 3.6

Claude Opus 4.849.9
GPT-5.153.5

Professional benchmark details

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

Aggregatereported

BenchLM overall score

SourceClaude Opus 4.8

Claude Opus 4.8

winner

76.0

Rank #8/100 · confidence 3 · eval date 2026-05-28

+20.0

GPT-5.1

56.0

Rank #50/100 · confidence 1 · eval date 2025-11-13

Pricingverified

Input price

SourceClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Claude Opus 4.8

$5.00/M

Rank #164/180 · confidence 4

+$3.75/M

GPT-5.1

winner

$1.25/M

Rank #119/180 · confidence 4

Pricingverified

Blended price

SourceClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Claude Opus 4.8

$10.00/M

Rank #165/180 · confidence 4

+$6.56/M

GPT-5.1

winner

$3.44/M

Rank #135/180 · confidence 4

Pricingverified

Output price

SourceClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Claude Opus 4.8

$25.00/M

Rank #165/180 · confidence 4

+$15.00/M

GPT-5.1

winner

$10.00/M

Rank #138/180 · confidence 4

Reasoningverified

HLE

SourceClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Claude Opus 4.8

winner

48.7%

Rank #6/209 · confidence 4

+20.2%

GPT-5.1

28.5%

Rank #56/209 · confidence 4

Reasoningreported

CritPt

SourceClaude Opus 4.8

Claude Opus 4.8

winner

20.9

Rank #10/83 · confidence 3 · eval date 2026-05-28

+16.0

GPT-5.1

4.9

Rank #43/83 · confidence 1 · eval date 2025-11-13

Reasoningverified

GPQA

SourceClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Claude Opus 4.8

winner

92.0%

Rank #17/212 · confidence 4

+4.7%

GPT-5.1

87.3%

Rank #48/212 · confidence 4

Reasoningreported

AA-LCR

SourceClaude Opus 4.8

Claude Opus 4.8

73.0

Rank #39/100 · confidence 3 · eval date 2026-05-28

+3.7

GPT-5.1

winner

76.7

Rank #19/100 · confidence 1 · eval date 2025-11-13

Codingreported

AA Coding Index

SourceClaude Opus 4.8

Claude Opus 4.8

winner

74.3

Rank #9/70 · confidence 3 · eval date 2026-05-28

+24.9

GPT-5.1

49.4

Rank #42/70 · confidence 1 · eval date 2025-11-13

Codingverified

SciCode

SourceClaude Opus 4.8 (Adaptive Reasoning, Max Effort)

Claude Opus 4.8

winner

53.5%

Rank #16/205 · confidence 4

+10.2%

GPT-5.1

43.3%

Rank #56/205 · confidence 4

Codingreported

AA-SciCode

SourceClaude Opus 4.8

Claude Opus 4.8

winner

53.5

Rank #18/108 · confidence 3 · eval date 2026-05-28

+10.2

GPT-5.1

43.3

Rank #55/108 · confidence 1 · eval date 2025-11-13

Mathreported

FrontierMath v2 (Tier 4)

SourceClaude Opus 4.8

Claude Opus 4.8

winner

31.3

Rank #7/35 · confidence 3 · eval date 2026-05-28

+18.8

GPT-5.1

12.5

Rank #16/35 · confidence 1 · eval date 2025-11-13

Mathreported

FrontierMath v2 (Tiers 1-3)

SourceClaude Opus 4.8

Claude Opus 4.8

winner

47.2

Rank #8/47 · confidence 3 · eval date 2026-05-28

+16.2

GPT-5.1

31.0

Rank #19/47 · confidence 1 · eval date 2025-11-13

Mathreported

BenchLM Math score

SourceClaude Opus 4.8

Claude Opus 4.8

winner

66.8

Rank #22/62 · confidence 3 · eval date 2026-05-28

+17.1

GPT-5.1

49.7

Rank #36/62 · confidence 1 · eval date 2025-11-13

Knowledgereported

AA-HLE

SourceClaude Opus 4.8

Claude Opus 4.8

winner

48.7

Rank #4/108 · confidence 3 · eval date 2026-05-28

+20.2

GPT-5.1

28.5

Rank #47/108 · confidence 1 · eval date 2025-11-13

Knowledgereported

AA-Omniscience Index

SourceClaude Opus 4.8

Claude Opus 4.8

winner

28.8

Rank #5/40 · confidence 3 · eval date 2026-05-28

+23.4

GPT-5.1

5.4

Rank #24/40 · confidence 1 · eval date 2025-11-13

Knowledgereported

Artificial Analysis Intelligence Index

SourceClaude Opus 4.8

Claude Opus 4.8

winner

57.3

Rank #7/111 · confidence 3 · eval date 2026-05-28

+19.9

GPT-5.1

37.5

Rank #52/111 · confidence 1 · eval date 2025-11-13

Knowledgereported

AA-Omniscience Accuracy

SourceClaude Opus 4.8

Claude Opus 4.8

winner

48.8

Rank #16/101 · confidence 3 · eval date 2026-05-28

+11.1

GPT-5.1

37.7

Rank #39/101 · confidence 1 · eval date 2025-11-13

Knowledgereported

AA-GPQA Diamond

SourceClaude Opus 4.8

Claude Opus 4.8

winner

92.0

Rank #17/108 · confidence 3 · eval date 2026-05-28

+4.7

GPT-5.1

87.3

Rank #44/108 · confidence 1 · eval date 2025-11-13

Knowledgereported

AA-Omniscience Hallucination Rate

SourceClaude Opus 4.8

Claude Opus 4.8

39.3

Rank #85/101 · confidence 3 · eval date 2026-05-28

+12.6

GPT-5.1

winner

51.9

Rank #72/101 · confidence 1 · eval date 2025-11-13

Multimodalreported

Design Arena Website

SourceClaude Opus 4.8

Claude Opus 4.8

winner

1273.0

Rank #28/75 · confidence 3 · eval date 2026-05-28

+75.0

GPT-5.1

1198.0

Rank #48/75 · confidence 1 · eval date 2025-11-13

Instruction followingreported

AA-IFBench

SourceClaude Opus 4.8

Claude Opus 4.8

62.2

Rank #49/84 · confidence 3 · eval date 2026-05-28

+10.7

GPT-5.1

winner

72.9

Rank #28/84 · confidence 1 · eval date 2025-11-13

Agentsreported

Gert Labs

SourceClaude Opus 4.8

Claude Opus 4.8

winner

73.0

Rank #1/49 · confidence 3 · eval date 2026-05-28

+31.7

GPT-5.1

41.2

Rank #34/49 · confidence 1 · eval date 2025-11-13

Agentsreported

GDPval-AA

SourceClaude Opus 4.8

Claude Opus 4.8

winner

1593.0

Rank #9/66 · confidence 3 · eval date 2026-05-28

+600.0

GPT-5.1

993.0

Rank #46/66 · confidence 1 · eval date 2025-11-13

Agentsreported

AA Agentic Index

SourceClaude Opus 4.8

Claude Opus 4.8

winner

49.4

Rank #10/65 · confidence 3 · eval date 2026-05-28

+27.7

GPT-5.1

21.6

Rank #47/65 · confidence 1 · eval date 2025-11-13

Agentsreported

GDPval-AA

SourceClaude Opus 4.8

Claude Opus 4.8

winner

53.9

Rank #10/61 · confidence 3 · eval date 2026-05-28

+29.3

GPT-5.1

24.6

Rank #46/61 · confidence 1 · eval date 2025-11-13

Agentsreported

τ²-bench results

SourceClaude Opus 4.8

Claude Opus 4.8

winner

94.4

Rank #23/82 · confidence 3 · eval date 2026-05-28

+12.5

GPT-5.1

81.9

Rank #53/82 · confidence 1 · eval date 2025-11-13

API audit comparison

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

Provider
Claude Opus 4.8
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
Claude Opus 4.8
GPT-5.1
BUZZ15 tests

Claude Opus 4.8

speed / latency

50 tok/s / 4823ms

input / output

No data

GPT-5.1

speed / latency

137 tok/s / 3299ms

input / output

No data

Fusecode10 tests

Claude Opus 4.8

speed / latency

43 tok/s / 2368ms

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

XShuLab Sub2API5 tests

Claude Opus 4.8

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

152 tok/s / 936ms

input / output

No data

42公益站0 tests

Claude Opus 4.8

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

6345ywz API0 tests

Claude Opus 4.8

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

Claude Opus 4.8

claude-opus-4-8

speed / latency

No data

input / output

$0/request

GPT-5.1

gpt-5.1-chat-latest

speed / latency

No data

input / output

$0/request

初叶🍂Furry API

Claude Opus 4.8

claude-opus-4-8

speed / latency

No data

input / output

$0.100/request

GPT-5.1

gpt-5-1

speed / latency

No data

input / output

$0/request

Yun API

Claude Opus 4.8

claude-opus-4-8

speed / latency

No data

input / output

$0.342/M/$1.71/M

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.0027/request

KFCV50

Claude Opus 4.8

claude-opus-4-8

speed / latency

No data

input / output

$0.017/request

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.0068/request

PoloAPI

Claude Opus 4.8

claude-opus-4-8-c

speed / latency

No data

input / output

$0.0082/request

GPT-5.1

gpt-5.1-chat-2025-11-13

speed / latency

No data

input / output

$0.137/M/$1.10/M

FAQ

Weighted outcome: Claude Opus 4.8. 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.