The Known Good Updated 25 Jul 2026
Anthropic: Claude Opus 4.6 vs OpenAI: GPT-5.1 ·Anthropic vs OpenAI

Anthropic: Claude Opus 4.6 vs OpenAI: GPT-5.1 — head-to-head comparison

Anthropic: Claude Opus 4.6 profile OpenAI: GPT-5.1 profile All comparisons
Anthropic: Claude Opus 4.6 — Anthropic
Quality
#11 of 61
88based on 5 of 6 evaluations
Known Good Index
Speed
#219 of 316
36.7
Output tokens per second
Price
#315 of 340
$10.00
Blended per 1M tokens
In $5.00 · Out $25.00
Cache hit price
#186 of 206
$0.50
per 1M tokens (−90%)
Context
#85 of 345
1.00M
tokens (~1,500 pages)
OpenAI: GPT-5.1 — OpenAI
Quality
#20 of 61
74based on 6 of 6 evaluations
Known Good Index
Speed
#119 of 316
61.9
Output tokens per second
Price
#261 of 340
$3.44
Blended per 1M tokens
In $1.25 · Out $10.00
Cache hit price
#105 of 206
$0.12
per 1M tokens (−90%)
Context
#101 of 345
400k
tokens (~600 pages)
Summary

On the Known Good Index, Anthropic: Claude Opus 4.6 scores 88 and OpenAI: GPT-5.1 scores 74 — a 14-point lead for Anthropic: Claude Opus 4.6. They share 5 published evaluations, with Anthropic: Claude Opus 4.6 ahead on 5 and OpenAI: GPT-5.1 ahead on 0.

Blended pricing is $10.00 per 1M tokens for Anthropic: Claude Opus 4.6 and $3.44 for OpenAI: GPT-5.1 — OpenAI: GPT-5.1 is about 2.9× cheaper.

Throughput is 37 tokens per second for Anthropic: Claude Opus 4.6 and 62 for OpenAI: GPT-5.1, with time to first token at 2.1s and 1.3s. Anthropic: Claude Opus 4.6 accepts 1.00M tokens of context against 400k.

Anthropic: Claude Opus 4.6 is proprietary; OpenAI: GPT-5.1 is proprietary. 5 tracked hosts serve one or both, and 1 serve both.

Generated from tracked data on 25 Jul 2026 · how these comparisons are computed →

At a glance
MetricAnthropic: Claude Opus 4.6OpenAI: GPT-5.1
Known Good Index 88 based on 5 of 6 evaluations 74 based on 6 of 6 evaluations
Blended $/1M $10.00 $3.44
Output tok/s 37 62
Context window 1.00M 400k
Providers 4 2
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Quality

Known Good Index and the capability indices, side by side

IndicesComponents
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 Opus 4.6OpenAI: GPT-5.1
Known Good Index 88 74
Coding Index 89 68
Mathematics Index 93 89
Science Index 95 91
Reasoning Index 84 80
Agentic Index 89 61
Openness Index 5 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = Anthropic: Claude Opus 4.6 · marker = OpenAI: GPT-5.1 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond91 / 88
MATH / AIME93 / 89
SWE-bench Verified79 / 68
Humanity's Last Exam34 / 24
Terminal-Bench80 / 48

Right-hand figures read Anthropic: Claude Opus 4.6 / OpenAI: GPT-5.1. Anthropic: Claude Opus 4.6 leads on 5 of 5, OpenAI: GPT-5.1 on 0.

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 Opus 4.6OpenAI: GPT-5.1
Text Arena 1,497 1,422
Text Arena (style controlled) 1,498 1,439
The Known Good

Price & Cost

Published API pricing by token type

Per token typeCache discount
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 Opus 4.6OpenAI: GPT-5.1
Input $/1M $5.00 $1.25
Output $/1M $25.00 $10.00
Blended $/1M $10.00 $3.44
Cache read $/1M $0.500 $0.125
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 Opus 4.6OpenAI: GPT-5.1
Context window 1.00M 400k
Max output tokens 128k 128k
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 Opus 4.6OpenAI: GPT-5.1
Output tokens/s 37 62
Time to first token 2.1s 1.3s
The Known Good

Providers

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

5 hosts · 1 serve both
Full provider benchmarks →
Provider Anthropic: Claude Opus 4.6 blendedAnthropic: Claude Opus 4.6 tok/s OpenAI: GPT-5.1 blendedOpenAI: GPT-5.1 tok/s
Google · first party $10.00 40 — —
Anthropic · first party $10.00 37 — —
Amazon Bedrock · first party $10.00 33 — —
Azure · first party $10.00 30 $3.44 58
OpenAI · first party — — $1.72 82

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 →