Why is this comparison indexable?

It has 3 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.

Back to models

Data points: 86

Key Takeaways

The readout for Claude Opus 4.6 and gpt-oss-20b, before the detailed comparison sheet.

Decision read

Claude Opus 4.6

Claude Opus 4.6 currently has the stronger profile, with verified wins split 3 to 0.

Evidence depth

86 data points

Includes 32 benchmark rows, 0 audit samples, and 0 provider examples.

Selection signal

Start with Claude Opus 4.6

The charts below split 32 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.

Model AModel B

Select a different model to open a new comparison URL.

Model compare Claude Opus 4.6 vs gpt-oss-20b claude-opus-4-6-vs-gpt-oss-20b	Model A Claude Opus 4.6	Model B gpt-oss-20b
Overall leader	Leading	Contender
Verified metric wins	3 wins	0 wins
Where it leads	Free providers, Provider coverage, Recent tests

Model compare

Claude Opus 4.6 vs gpt-oss-20b

claude-opus-4-6-vs-gpt-oss-20b

Model A

Claude Opus 4.6

Model B

gpt-oss-20b

Overall leader

Leading

Contender

Verified metric wins

3 wins

0 wins

Where it leads

Free providers, Provider coverage, Recent tests

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

Claude Opus 4.6gpt-oss-20b

Avg. score

Claude Opus 4.6

64.1

Avg. score

gpt-oss-20b

Selected category

Agents

Claude Opus 4.6 leads by 29.9

Professional benchmark details

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

Group

Aggregateverified

BenchLM overall score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

84.0

Rank #5/96 · confidence 4 · eval date 2026-02-01

+65.0

gpt-oss-20b

19.0

Rank #87/96 · confidence 1 · eval date 2025-08-05

Performanceverified

Time to first token

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

2.11 s

Rank #84/113 · confidence 4

+1.61 s

gpt-oss-20b

winner

0.50 s

Rank #6/113 · confidence 4

Performanceverified

Output speed

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

47.6 tok/s

Rank #93/113 · confidence 4

+177.9 tok/s

gpt-oss-20b

winner

225.5 tok/s

Rank #8/113 · confidence 4

Performanceverified

Time to first answer token

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

winner

2.11 s

Rank #51/113 · confidence 4

+7.26 s

gpt-oss-20b

9.37 s

Rank #63/113 · confidence 4

Pricingverified

Blended price

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

$10.00/M

Rank #125/138 · confidence 4

+$9.90/M

gpt-oss-20b

winner

$0.095/M

Rank #3/138 · confidence 4

Pricingverified

Input price

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

$5.00/M

Rank #124/138 · confidence 4

+$4.94/M

gpt-oss-20b

winner

$0.060/M

Rank #4/138 · confidence 4

Pricingverified

Output price

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

$25.00/M

Rank #125/138 · confidence 4

+$24.80/M

gpt-oss-20b

winner

$0.200/M

Rank #4/138 · confidence 4

Reasoningverified

BenchLM Reasoning score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

87.8

Rank #2/65 · confidence 4 · eval date 2026-02-01

+75.4

gpt-oss-20b

12.4

Rank #64/65 · confidence 1 · eval date 2025-08-05

Reasoningverified

CritPt

SourceClaude Opus 4.6

Claude Opus 4.6

winner

2.8

Rank #27/54 · confidence 4 · eval date 2026-02-01

+1.4

gpt-oss-20b

1.4

Rank #33/54 · confidence 1 · eval date 2025-08-05

Reasoningverified

GPQA

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

winner

84.0%

Rank #37/152 · confidence 4

+22.9%

gpt-oss-20b

61.1%

Rank #110/152 · confidence 4

Reasoningverified

AA-LCR

SourceClaude Opus 4.6

Claude Opus 4.6

winner

58.3

Rank #44/67 · confidence 4 · eval date 2026-02-01

+27.6

gpt-oss-20b

30.7

Rank #60/67 · confidence 1 · eval date 2025-08-05

Reasoningverified

MMLU-Pro

SourceClaude Opus 4.6

Claude Opus 4.6

winner

82.0%

Rank #44/113 · confidence 4 · eval date 2026-02-01

+10.2%

gpt-oss-20b

71.8%

Rank #91/113 · confidence 4

Reasoningverified

HLE

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

winner

18.6%

Rank #46/150 · confidence 4

+13.5%

gpt-oss-20b

5.1%

Rank #105/150 · confidence 4

Codingverified

React Native Evals

SourceClaude Opus 4.6

Claude Opus 4.6

winner

84.1

Rank #2/11 · confidence 4 · eval date 2026-02-01

+13.1

gpt-oss-20b

71.0

Rank #11/11 · confidence 1 · eval date 2025-08-05

Codingverified

BenchLM Coding score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

82.4

Rank #9/83 · confidence 4 · eval date 2026-02-01

+67.9

gpt-oss-20b

14.5

Rank #81/83 · confidence 1 · eval date 2025-08-05

Codingverified

Terminal-Bench Hard

SourceClaude Opus 4.6

Claude Opus 4.6

winner

48.5

Rank #9/69 · confidence 4 · eval date 2026-02-01

+37.9

gpt-oss-20b

10.6

Rank #60/69 · confidence 1 · eval date 2025-08-05

Codingverified

SciCode

SourceClaude Opus 4.6 (Non-reasoning, High Effort)

Claude Opus 4.6

winner

45.7%

Rank #22/149 · confidence 4

+11.7%

gpt-oss-20b

34.0%

Rank #92/149 · confidence 4

Codingverified

AA-SciCode

SourceClaude Opus 4.6

Claude Opus 4.6

winner

45.7

Rank #23/74 · confidence 4 · eval date 2026-02-01

+11.3

gpt-oss-20b

34.4

Rank #60/74 · confidence 1 · eval date 2025-08-05

Knowledgeverified

AA-Omniscience Hallucination Rate

SourceClaude Opus 4.6

Claude Opus 4.6

76.0

Rank #35/68 · confidence 4 · eval date 2026-02-01

+18.1

gpt-oss-20b

winner

94.1

Rank #2/68 · confidence 1 · eval date 2025-08-05

Knowledgeverified

BenchLM Knowledge score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

91.6

Rank #2/79 · confidence 4 · eval date 2026-02-01

+81.1

gpt-oss-20b

10.5

Rank #79/79 · confidence 1 · eval date 2025-08-05

Knowledgeverified

AA-Omniscience Accuracy

SourceClaude Opus 4.6

Claude Opus 4.6

winner

45.2

Rank #8/68 · confidence 4 · eval date 2026-02-01

+29.7

gpt-oss-20b

15.5

Rank #63/68 · confidence 1 · eval date 2025-08-05

Knowledgeverified

Artificial Analysis Intelligence Index

SourceClaude Opus 4.6

Claude Opus 4.6

winner

37.8

Rank #25/77 · confidence 4 · eval date 2026-02-01

+22.9

gpt-oss-20b

14.9

Rank #63/77 · confidence 1 · eval date 2025-08-05

Knowledgeverified

AA-GPQA Diamond

SourceClaude Opus 4.6

Claude Opus 4.6

winner

84.0

Rank #37/74 · confidence 4 · eval date 2026-02-01

+15.2

gpt-oss-20b

68.8

Rank #56/74 · confidence 1 · eval date 2025-08-05

Knowledgeverified

AA-HLE

SourceClaude Opus 4.6

Claude Opus 4.6

winner

18.6

Rank #40/74 · confidence 4 · eval date 2026-02-01

+8.8

gpt-oss-20b

9.8

Rank #51/74 · confidence 1 · eval date 2025-08-05

Multilingualverified

BenchLM Multilingual score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

100.0

Rank #1/59 · confidence 4 · eval date 2026-02-01

+94.4

gpt-oss-20b

5.6

Rank #53/59 · confidence 1 · eval date 2025-08-05

Multimodalverified

Design Arena Website

SourceClaude Opus 4.6

Claude Opus 4.6

winner

1337.0

Rank #2/50 · confidence 4 · eval date 2026-02-01

+442.0

gpt-oss-20b

895.0

Rank #48/50 · confidence 1 · eval date 2025-08-05

Multimodalverified

BenchLM Multimodal Grounded score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

75.4

Rank #14/70 · confidence 4 · eval date 2026-02-01

+66.6

gpt-oss-20b

8.8

Rank #70/70 · confidence 1 · eval date 2025-08-05

Instruction followingverified

BenchLM Instruction Following score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

91.3

Rank #2/66 · confidence 4 · eval date 2026-02-01

+71.0

gpt-oss-20b

20.3

Rank #66/66 · confidence 1 · eval date 2025-08-05

Instruction followingverified

AA-IFBench

SourceClaude Opus 4.6

Claude Opus 4.6

44.6

Rank #47/70 · confidence 4 · eval date 2026-02-01

+20.5

gpt-oss-20b

winner

65.1

Rank #36/70 · confidence 1 · eval date 2025-08-05

Agentsverified

APEX-Agents-AA

SourceClaude Opus 4.6 (Adaptive)

Claude Opus 4.6

winner

33.0

Rank #3/16 · confidence 1 · eval date 2026-02-01

+32.3

gpt-oss-20b

0.7

Rank #16/16 · confidence 1 · eval date 2025-08-05

Agentsverified

BenchLM Agentic score

SourceClaude Opus 4.6

Claude Opus 4.6

winner

80.1

Rank #12/81 · confidence 4 · eval date 2026-02-01

+62.5

gpt-oss-20b

17.6

Rank #75/81 · confidence 1 · eval date 2025-08-05

Agentsverified

Tau2-Telecom

SourceClaude Opus 4.6

Claude Opus 4.6

winner

84.8

Rank #31/68 · confidence 4 · eval date 2026-02-01

+24.6

gpt-oss-20b

60.2

Rank #50/68 · confidence 1 · eval date 2025-08-05

API audit comparison

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

Provider	Claude Opus 4.6	gpt-oss-20b
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 4.6	gpt-oss-20b
No shared provider examples are available yet.

When to choose each model

This report only uses LMSpeed data for Claude Opus 4.6 and gpt-oss-20b: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Guidance	Claude Opus 4.6	gpt-oss-20b
When to choose each model	Claude Opus 4.6 Claude Opus 4.6 is stronger when you prioritize Free providers, Provider coverage, Recent tests.	gpt-oss-20b gpt-oss-20b does not clearly lead on the verified metrics here, so check provider-specific pricing before choosing.

FAQ

TL;DR: Claude Opus 4.6 leads across 86 verifiable data points, including pricing, speed, latency, benchmarks, and provider examples.

Why is this comparison indexable?: It has 3 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.

Continue from Claude Opus 4.6 vs gpt-oss-20b into nearby model comparisons with enough verified LMSpeed data.

Model metadata	Claude Opus 4.6 exposes 1M tokens; notable signals: Text input, Image input, File input, Text output.	gpt-oss-20b exposes 131.1K tokens; notable signals: Text input, Text output, Tool calling, Structured outputs.
Developer	Anthropic	OpenAI
Context window	1M tokens	131.1K tokens
Max output	128K tokens	No data
Released	Feb 2026	No data
Modalities	Input TextImageFile Output Text	Input Text Output Text
Features	Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning	Text inputText outputTool callingStructured outputsJSON modeReasoning
Parameters	No data	20B
Tokenizer	Claude	GPT
Knowledge cutoff	No data	2024-06-30
OpenRouter ID	anthropic/claude-opus-4.6	openai/gpt-oss-20b
References	No data	No data

Key Takeaways

Change comparison

Claude Opus 4.6 vs gpt-oss-20b

Claude Opus 4.6

gpt-oss-20b

Benchmark score comparison

Category performance

Professional benchmark details

BenchLM overall score

Time to first token

Output speed

Time to first answer token

Blended price

Input price

Output price

BenchLM Reasoning score

CritPt

GPQA

AA-LCR

MMLU-Pro

HLE

React Native Evals

BenchLM Coding score

Terminal-Bench Hard

SciCode

AA-SciCode

AA-Omniscience Hallucination Rate

BenchLM Knowledge score

AA-Omniscience Accuracy

Artificial Analysis Intelligence Index

AA-GPQA Diamond

AA-HLE

BenchLM Multilingual score

Design Arena Website

BenchLM Multimodal Grounded score

BenchLM Instruction Following score

AA-IFBench

APEX-Agents-AA

BenchLM Agentic score

Tau2-Telecom

API audit comparison

Provider examples

When to choose each model

FAQ

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