The Known Good Updated 8 Sep 2026 Subscribe
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
#18 of 65
80based on 4 of 7 evaluations
Known Good Index
Speed
#212 of 341
41.2
Output tokens per second
Price
#398 of 450
$6.00
Blended per 1M tokens
In $3.00 · Out $15.00
Cache hit price
#294 of 344
$0.30
per 1M tokens (−90%)
Context
#120 of 487
1.00M
tokens (~1,500 pages)
OpenAI: gpt-oss-120b — OpenAI
Quality
#44 of 65
62based on 3 of 7 evaluations
Known Good Index
Speed
#10 of 341
166.1
Output tokens per second
Price
#19 of 450
$0.07
Blended per 1M tokens
In $0.04 · Out $0.17
Cache hit price
unranked
per 1M tokens
Context
#372 of 487
131k
tokens (~200 pages)
Summary

On the Known Good Index, Anthropic: Claude Sonnet 4.6 scores 80 and OpenAI: gpt-oss-120b scores 62 — 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 41 tokens per second for Anthropic: Claude Sonnet 4.6 and 166 for OpenAI: gpt-oss-120b, with time to first token at 1.5s and 0.7s. 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). 21 tracked hosts serve one or both, and 2 serve both.

Generated from tracked data on 9 Sep 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 62 based on 3 of 7 evaluations
Blended $/1M $6.00 $0.07
Output tok/s 41 166
Context window 1.00M 131k
Providers 5 18
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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 62
Coding Index 73
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 1,458 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
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 118k
The Known Good

Speed & Latency

Mean throughput and time to first token across hosting providers, over successful measurements from the last 48 hours

Throughput and latency

Means across all tracked providers over successful measurements from the last 48 hours, derived from OpenRouter endpoint telemetry.

MetricAnthropic: Claude Sonnet 4.6OpenAI: gpt-oss-120b
Output tokens/s 41 166
Time to first token 1.5s 0.7s
The Known Good

Providers

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

21 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
Amazon Bedrock · first party $6.00 78 $0.26 288
Azure · first party $6.00 44
Claude Platform on AWS $6.00 41
Google · first party $6.00 41 $0.16 196
Anthropic · first party $6.00 31
Cerebras $0.45 833
Groq $0.26 304
Nebius $0.26 281
BaseTen $0.20 224
SambaNova $0.34 183
Mara $0.30 120
DeepInfra $0.07 105
Parasail $0.26 96
Together $0.26 84
Phala $0.26 67
Novita $0.10 61
Mancer 2 $0.17 54
AkashML $0.07 50
CoreWeave $0.07 45
DigitalOcean $0.14 29
SiliconFlow $0.15 10

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 →