The Known Good Updated 29 Jul 2026
Anthropic: Claude Sonnet 4.6 vs OpenAI: gpt-oss-120b ·Anthropic vs OpenAI

Anthropic: Claude Sonnet 4.6 vs OpenAI: gpt-oss-120b — head-to-head comparison

Anthropic: Claude Sonnet 4.6 profile OpenAI: gpt-oss-120b profile All comparisons
Anthropic: Claude Sonnet 4.6 — Anthropic
Quality
#17 of 62
80based on 4 of 7 evaluations
Known Good Index
Speed
#182 of 317
43.9
Output tokens per second
Price
#329 of 370
$6.00
Blended per 1M tokens
In $3.00 · Out $15.00
Cache hit price
#195 of 238
$0.30
per 1M tokens (−90%)
Context
#73 of 375
1.00M
tokens (~1,500 pages)
OpenAI: gpt-oss-120b — OpenAI
Quality
#42 of 62
61based on 3 of 7 evaluations
Known Good Index
Speed
#13 of 317
144.7
Output tokens per second
Price
#35 of 370
$0.07
Blended per 1M tokens
In $0.04 · Out $0.17
Cache hit price
#28 of 238
$0.015
per 1M tokens (−59%)
Context
#265 of 375
131k
tokens (~200 pages)
Summary

On the Known Good Index, Anthropic: Claude Sonnet 4.6 scores 80 and OpenAI: gpt-oss-120b scores 61 — a 19-point lead for Anthropic: Claude Sonnet 4.6. They share 3 published evaluations, with Anthropic: Claude Sonnet 4.6 ahead on 2 and OpenAI: gpt-oss-120b ahead on 1.

Blended pricing is $6.00 per 1M tokens for Anthropic: Claude Sonnet 4.6 and $0.07 for OpenAI: gpt-oss-120b — OpenAI: gpt-oss-120b is about 85.4× cheaper.

Throughput is 44 tokens per second for Anthropic: Claude Sonnet 4.6 and 145 for OpenAI: gpt-oss-120b, with time to first token at 1.7s and 0.9s. Anthropic: Claude Sonnet 4.6 accepts 1.00M tokens of context against 131k.

Anthropic: Claude Sonnet 4.6 is proprietary; OpenAI: gpt-oss-120b is open weights under Open weights (unrestricted). 19 tracked hosts serve one or both, and 2 serve both.

Generated from tracked data on 29 Jul 2026 · how these comparisons are computed →

At a glance
MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Known Good Index 80 based on 4 of 7 evaluations 61 based on 3 of 7 evaluations
Blended $/1M $6.00 $0.07
Output tok/s 44 145
Context window 1.00M 131k
Providers 4 17
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Quality

Known Good Index and the capability indices, side by side

Index scores

Each index is min-max normalised across tracked models and scaled 0–100 from published evaluations. We do not run these evaluations.

MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Known Good Index 80 61
Coding Index 71
Mathematics Index 86 89
Agentic Index 71 18
Openness Index 5 60
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = Anthropic: Claude Sonnet 4.6 · marker = OpenAI: gpt-oss-120b · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond87 / 76
Mock AIME 2024–2586 / 89
Terminal-Bench53 / 19

Right-hand figures read Anthropic: Claude Sonnet 4.6 / OpenAI: gpt-oss-120b. Anthropic: Claude Sonnet 4.6 leads on 2 of 3, OpenAI: gpt-oss-120b on 1.

The Known Good

Arena Elo

Human preference rating from blind pairwise votes

Arena ratings

Elo from blind pairwise votes, ingested from Arena. Higher is better.

MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Text Arena 1,457 1,366
Text Arena (style controlled) 1,472 1,352
The Known Good

Price & Cost

Published API pricing by token type

Published pricing

USD per 1M tokens. Blended is a 3:1 input:output mix. Live from OpenRouter, cross-checked against models.dev. Lower is better.

MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Input $/1M $3.00 $0.04
Output $/1M $15.00 $0.17
Blended $/1M $6.00 $0.07
Cache read $/1M $0.300 $0.015
The Known Good
We publish blended price rather than cost-per-task. Cost-per-task requires token counts from an evaluation suite we do not run. Blended price is computed from published rates and is fully reproducible — see the pricing methodology.

Context Window

Maximum input accepted and maximum output emitted

Context and output limits

Provider-declared limits, from metadata via models.dev and OpenRouter. Higher is better.

MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Context window 1.00M 131k
Max output tokens 128k 131k
The Known Good

Speed & Latency

Median throughput and time to first token across hosting providers

Output speedTime to first token
Throughput and latency

Medians across all tracked providers, derived from OpenRouter endpoint telemetry.

MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Output tokens/s 44 145
Time to first token 1.7s 0.9s
The Known Good

Providers

Which hosts serve each model, and at what price and speed

19 hosts · 2 serve both
Full provider benchmarks →
Provider Anthropic: Claude Sonnet 4.6 blendedAnthropic: Claude Sonnet 4.6 tok/s OpenAI: gpt-oss-120b blendedOpenAI: gpt-oss-120b tok/s
Google · first party $6.00 52 $0.16 177
Anthropic · first party $6.00 38
Azure · first party $6.00 38
Amazon Bedrock · first party $6.00 36 $0.26 342
Cerebras $0.45 501
SambaNova $0.34 367
Groq $0.26 352
Nebius $0.26 231
DeepInfra $0.07 196
BaseTen $0.20 171
Mara $0.30 146
Together $0.26 114
Parasail $0.26 101
Phala $0.26 82
Novita $0.10 64
Mancer 2 $0.17 40
CoreWeave $0.07 32
DigitalOcean $0.17 22
SiliconFlow $0.15 12

Per-host pricing and telemetry from OpenRouter. A dash means that host does not serve that model.

The Known Good
Sources for this page
Pricing & providers — OpenRouter Metadata — models.dev Benchmarks — Epoch AI (CC-BY 4.0)Elo — Arena Full attribution →