The Known Good Updated 25 Jul 2026
claude-opus-4-5-20251101 vs OpenAI: GPT-5 Nano ·Anthropic vs OpenAI

claude-opus-4-5-20251101 vs OpenAI: GPT-5 Nano — head-to-head comparison

claude-opus-4-5-20251101 profile OpenAI: GPT-5 Nano profile All comparisons
claude-opus-4-5-20251101 — Anthropic
Quality
#22 of 61
72based on 5 of 6 evaluations
Known Good Index
Speed
unranked
—
Output tokens per second
Price
unranked
—
Blended per 1M tokens
Cache hit price
unranked
—
per 1M tokens
Context
unranked
—
tokens
OpenAI: GPT-5 Nano — OpenAI
Quality
#37 of 61
57based on 3 of 6 evaluations
Known Good Index
Speed
#28 of 316
120.9
Output tokens per second
Price
#56 of 340
$0.14
Blended per 1M tokens
In $0.05 · Out $0.40
Cache hit price
#13 of 206
$0.005
per 1M tokens (−90%)
Context
#105 of 345
400k
tokens (~600 pages)
Summary

On the Known Good Index, claude-opus-4-5-20251101 scores 72 and OpenAI: GPT-5 Nano scores 57 — a 14-point lead for claude-opus-4-5-20251101. They share 3 published evaluations, with claude-opus-4-5-20251101 ahead on 3 and OpenAI: GPT-5 Nano ahead on 0.

Published pricing is tracked for OpenAI: GPT-5 Nano only, at $0.14 per 1M tokens blended.

claude-opus-4-5-20251101 is proprietary; OpenAI: GPT-5 Nano is proprietary. 2 tracked hosts serve one or both.

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

At a glance
Metricclaude-opus-4-5-20251101OpenAI: GPT-5 Nano
Known Good Index 72 based on 5 of 6 evaluations 57 based on 3 of 6 evaluations
Blended $/1M — $0.14
Output tok/s — 121
Context window — 400k
Providers 0 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.

Metricclaude-opus-4-5-20251101OpenAI: GPT-5 Nano
Known Good Index 72 57
Coding Index 78 —
Mathematics Index 86 89
Science Index 89 69
Reasoning Index 58 —
Agentic Index 78 21
Openness Index 5 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = claude-opus-4-5-20251101 · marker = OpenAI: GPT-5 Nano · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond86 / 69
MATH / AIME86 / 81
Terminal-Bench63 / 22

Right-hand figures read claude-opus-4-5-20251101 / OpenAI: GPT-5 Nano. claude-opus-4-5-20251101 leads on 3 of 3, OpenAI: GPT-5 Nano 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.

Metricclaude-opus-4-5-20251101OpenAI: GPT-5 Nano
Text Arena 1,450 —
Text Arena (style controlled) 1,469 —
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.

Metricclaude-opus-4-5-20251101OpenAI: GPT-5 Nano
Input $/1M — $0.05
Output $/1M — $0.40
Blended $/1M — $0.14
Cache read $/1M — $0.005
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.

Metricclaude-opus-4-5-20251101OpenAI: GPT-5 Nano
Context window — 400k
Max output tokens — 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.

Metricclaude-opus-4-5-20251101OpenAI: GPT-5 Nano
Output tokens/s — 121
Time to first token — 2.9s
The Known Good

Providers

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

2 hosts
Full provider benchmarks →
Provider claude-opus-4-5-20251101 blendedclaude-opus-4-5-20251101 tok/s OpenAI: GPT-5 Nano blendedOpenAI: GPT-5 Nano tok/s
OpenAI · first party — — $0.07 225
Azure · first party — — $0.14 69

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 →