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: 93

Key Takeaways

The readout for GPT-5 and gpt-oss-20b, before the detailed comparison sheet.

Decision read

GPT-5

GPT-5 currently has the stronger profile, with verified wins split 3 to 0.

Evidence depth

93 data points

Includes 35 benchmark rows, 0 audit samples, and 0 provider examples.

Selection signal

Start with GPT-5

The charts below split 35 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 GPT-5 vs gpt-oss-20b gpt-5-vs-gpt-oss-20b	Model A GPT-5	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

GPT-5 vs gpt-oss-20b

gpt-5-vs-gpt-oss-20b

Model A

GPT-5

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

GPT-5gpt-oss-20b

Avg. score

GPT-5

Avg. score

gpt-oss-20b

Selected category

Agents

GPT-5 leads by 26.5

Professional benchmark details

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

Group

Aggregateverified

BenchLM overall score

SourceGPT-5 (high)

GPT-5

winner

72.0

Rank #21/96 · confidence 1 · eval date 2025-08-07

+53.0

gpt-oss-20b

19.0

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

Performanceverified

Time to first token

SourceGPT-5 (minimal)

GPT-5

0.88 s

Rank #32/113 · confidence 4

+0.38 s

gpt-oss-20b

winner

0.50 s

Rank #6/113 · confidence 4

Performanceverified

Output speed

SourceGPT-5 (minimal)

GPT-5

67.2 tok/s

Rank #70/113 · confidence 4

+158.3 tok/s

gpt-oss-20b

winner

225.5 tok/s

Rank #8/113 · confidence 4

Performanceverified

Time to first answer token

SourceGPT-5 (minimal)

GPT-5

winner

0.88 s

Rank #24/113 · confidence 4

+8.48 s

gpt-oss-20b

9.37 s

Rank #63/113 · confidence 4

Pricingverified

Blended price

SourceGPT-5 (minimal)

GPT-5

$3.44/M

Rank #101/138 · confidence 4

+$3.34/M

gpt-oss-20b

winner

$0.095/M

Rank #3/138 · confidence 4

Pricingverified

Input price

SourceGPT-5 (minimal)

GPT-5

$1.25/M

Rank #94/138 · confidence 4

+$1.19/M

gpt-oss-20b

winner

$0.060/M

Rank #4/138 · confidence 4

Pricingverified

Output price

SourceGPT-5 (minimal)

GPT-5

$10.00/M

Rank #103/138 · confidence 4

+$9.80/M

gpt-oss-20b

winner

$0.200/M

Rank #4/138 · confidence 4

Reasoningverified

AA-LCR

SourceGPT-5 (high)

GPT-5

winner

75.6

Rank #2/67 · confidence 1 · eval date 2025-08-07

+44.9

gpt-oss-20b

30.7

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

Reasoningverified

BenchLM Reasoning score

SourceGPT-5 (high)

GPT-5

winner

71.7

Rank #13/65 · confidence 1 · eval date 2025-08-07

+59.3

gpt-oss-20b

12.4

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

Reasoningverified

CritPt

SourceGPT-5 (high)

GPT-5

winner

5.7

Rank #16/54 · confidence 1 · eval date 2025-08-07

+4.3

gpt-oss-20b

1.4

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

Reasoningverified

MMLU-Pro

SourceGPT-5 (minimal)

GPT-5

winner

80.6%

Rank #53/113 · confidence 4

+8.8%

gpt-oss-20b

71.8%

Rank #91/113 · confidence 4

Reasoningverified

GPQA

SourceGPT-5 (minimal)

GPT-5

winner

67.3%

Rank #95/152 · confidence 4

+6.2%

gpt-oss-20b

61.1%

Rank #110/152 · confidence 4

Reasoningverified

HLE

SourceGPT-5 (minimal)

GPT-5

winner

5.4%

Rank #102/150 · confidence 4

+0.3%

gpt-oss-20b

5.1%

Rank #105/150 · confidence 4

Codingverified

AA Coding Index

SourceGPT-5 (high)

GPT-5

winner

37.8

Rank #23/36 · confidence 1 · eval date 2025-08-07

+17.1

gpt-oss-20b

20.7

Rank #30/36 · confidence 1 · eval date 2025-08-05

Codingverified

AA-SciCode

SourceGPT-5 (high)

GPT-5

winner

42.9

Rank #30/74 · confidence 1 · eval date 2025-08-07

+8.5

gpt-oss-20b

34.4

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

Codingverified

Terminal-Bench Hard

SourceGPT-5 (high)

GPT-5

winner

32.6

Rank #37/69 · confidence 1 · eval date 2025-08-07

+22.0

gpt-oss-20b

10.6

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

Codingverified

LiveCodeBench

SourceGPT-5 (minimal)

GPT-5

55.8%

Rank #51/108 · confidence 4

+9.4%

gpt-oss-20b

winner

65.2%

Rank #39/108 · confidence 4

Codingverified

BenchLM Coding score

SourceGPT-5 (high)

GPT-5

winner

64.3

Rank #42/83 · confidence 1 · eval date 2025-08-07

+49.8

gpt-oss-20b

14.5

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

Codingverified

SciCode

SourceGPT-5 (minimal)

GPT-5

winner

38.8%

Rank #65/149 · confidence 4

+4.8%

gpt-oss-20b

34.0%

Rank #92/149 · confidence 4

Knowledgeverified

AA-Omniscience Hallucination Rate

SourceGPT-5 (high)

GPT-5

82.1

Rank #24/68 · confidence 1 · eval date 2025-08-07

+12.0

gpt-oss-20b

winner

94.1

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

Knowledgeverified

AA-Omniscience Accuracy

SourceGPT-5 (high)

GPT-5

winner

40.7

Rank #12/68 · confidence 1 · eval date 2025-08-07

+25.2

gpt-oss-20b

15.5

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

Knowledgeverified

BenchLM Knowledge score

SourceGPT-5 (high)

GPT-5

winner

75.3

Rank #17/79 · confidence 1 · eval date 2025-08-07

+64.8

gpt-oss-20b

10.5

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

Knowledgeverified

AA-HLE

SourceGPT-5 (high)

GPT-5

winner

26.5

Rank #23/74 · confidence 1 · eval date 2025-08-07

+16.7

gpt-oss-20b

9.8

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

Knowledgeverified

AA-GPQA Diamond

SourceGPT-5 (high)

GPT-5

winner

85.4

Rank #30/74 · confidence 1 · eval date 2025-08-07

+16.6

gpt-oss-20b

68.8

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

Knowledgeverified

Artificial Analysis Intelligence Index

SourceGPT-5 (high)

GPT-5

winner

34.7

Rank #32/77 · confidence 1 · eval date 2025-08-07

+19.8

gpt-oss-20b

14.9

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

Multilingualverified

BenchLM Multilingual score

SourceGPT-5 (high)

GPT-5

winner

78.4

Rank #13/59 · confidence 1 · eval date 2025-08-07

+72.8

gpt-oss-20b

5.6

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

Multimodalverified

BenchLM Multimodal Grounded score

SourceGPT-5 (high)

GPT-5

winner

89.2

Rank #4/70 · confidence 1 · eval date 2025-08-07

+80.4

gpt-oss-20b

8.8

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

Multimodalverified

Design Arena Website

SourceGPT-5 (high)

GPT-5

winner

1227.0

Rank #28/50 · confidence 1 · eval date 2025-08-07

+332.0

gpt-oss-20b

895.0

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

Instruction followingverified

AA-IFBench

SourceGPT-5 (high)

GPT-5

winner

73.1

Rank #22/70 · confidence 1 · eval date 2025-08-07

+8.0

gpt-oss-20b

65.1

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

Instruction followingverified

BenchLM Instruction Following score

SourceGPT-5 (high)

GPT-5

winner

75.5

Rank #25/66 · confidence 1 · eval date 2025-08-07

+55.2

gpt-oss-20b

20.3

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

Agentsverified

AA Agentic Index

SourceGPT-5 (high)

GPT-5

winner

25.7

Rank #14/32 · confidence 1 · eval date 2025-08-07

+22.6

gpt-oss-20b

3.1

Rank #27/32 · confidence 1 · eval date 2025-08-05

Agentsverified

BenchLM Agentic score

SourceGPT-5 (high)

GPT-5

winner

75.2

Rank #16/81 · confidence 1 · eval date 2025-08-07

+57.6

gpt-oss-20b

17.6

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

Agentsverified

GDPval-AA

SourceGPT-5 (high)

GPT-5

winner

28.7

Rank #16/27 · confidence 1 · eval date 2025-08-07

+26.0

gpt-oss-20b

2.7

Rank #27/27 · confidence 1 · eval date 2025-08-05

Agentsverified

GDPval-AA

SourceGPT-5 (high)

GPT-5

winner

1074.0

Rank #17/33 · confidence 1 · eval date 2025-08-07

+520.0

gpt-oss-20b

554.0

Rank #28/33 · confidence 1 · eval date 2025-08-05

Agentsverified

Tau2-Telecom

SourceGPT-5 (high)

GPT-5

winner

84.8

Rank #31/68 · confidence 1 · eval date 2025-08-07

+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	GPT-5	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	GPT-5	gpt-oss-20b
No shared provider examples are available yet.

When to choose each model

This report only uses LMSpeed data for GPT-5 and gpt-oss-20b: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Guidance	GPT-5	gpt-oss-20b
When to choose each model	GPT-5 GPT-5 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: GPT-5 leads across 93 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 GPT-5 vs gpt-oss-20b into nearby model comparisons with enough verified LMSpeed data.

Model metadata	GPT-5 exposes 400K 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	OpenAI	OpenAI
Context window	400K tokens	131.1K tokens
Max output	128K tokens	No data
Released	Aug 2025	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	GPT	GPT
Knowledge cutoff	2024-09-30	2024-06-30
OpenRouter ID	openai/gpt-5	openai/gpt-oss-20b
References	No data	No data

Key Takeaways

Change comparison

GPT-5 vs gpt-oss-20b

GPT-5

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

AA-LCR

BenchLM Reasoning score

CritPt

MMLU-Pro

GPQA

HLE

AA Coding Index

AA-SciCode

Terminal-Bench Hard

LiveCodeBench

BenchLM Coding score

SciCode

AA-Omniscience Hallucination Rate

AA-Omniscience Accuracy

BenchLM Knowledge score

AA-HLE

AA-GPQA Diamond

Artificial Analysis Intelligence Index

BenchLM Multilingual score

BenchLM Multimodal Grounded score

Design Arena Website

AA-IFBench

BenchLM Instruction Following score

AA Agentic Index

BenchLM Agentic score

GDPval-AA

GDPval-AA

Tau2-Telecom

API audit comparison

Provider examples

When to choose each model

FAQ

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