The Known Good Updated 25 Jul 2026
OpenAI: GPT-5.1 vs OpenAI: GPT-5.2 ·OpenAI vs OpenAI

OpenAI: GPT-5.1 vs OpenAI: GPT-5.2 — head-to-head comparison

OpenAI: GPT-5.1 profile OpenAI: GPT-5.2 profile All comparisons
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)
OpenAI: GPT-5.2 — OpenAI
Quality
#16 of 61
80based on 5 of 6 evaluations
Known Good Index
Speed
#151 of 316
53.9
Output tokens per second
Price
#295 of 340
$4.81
Blended per 1M tokens
In $1.75 · Out $14.00
Cache hit price
#134 of 206
$0.17
per 1M tokens (−90%)
Context
#106 of 345
400k
tokens (~600 pages)
Summary

On the Known Good Index, OpenAI: GPT-5.1 scores 74 and OpenAI: GPT-5.2 scores 80 — a 6-point lead for OpenAI: GPT-5.2. They share 5 published evaluations, with OpenAI: GPT-5.1 ahead on 0 and OpenAI: GPT-5.2 ahead on 5.

Blended pricing is $3.44 per 1M tokens for OpenAI: GPT-5.1 and $4.81 for OpenAI: GPT-5.2 — OpenAI: GPT-5.1 is about 1.4× cheaper.

Throughput is 62 tokens per second for OpenAI: GPT-5.1 and 54 for OpenAI: GPT-5.2, with time to first token at 1.3s and 2.5s. OpenAI: GPT-5.1 accepts 400k tokens of context against 400k.

OpenAI: GPT-5.1 is proprietary; OpenAI: GPT-5.2 is proprietary. 2 tracked hosts serve one or both, and 2 serve both.

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

At a glance
MetricOpenAI: GPT-5.1OpenAI: GPT-5.2
Known Good Index 74 based on 6 of 6 evaluations 80 based on 5 of 6 evaluations
Blended $/1M $3.44 $4.81
Output tok/s 62 54
Context window 400k 400k
Providers 2 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.

MetricOpenAI: GPT-5.1OpenAI: GPT-5.2
Known Good Index 74 80
Coding Index 68 76
Mathematics Index 89 96
Science Index 91 96
Reasoning Index 80 77
Agentic Index 61 76
Openness Index 5 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = OpenAI: GPT-5.1 · marker = OpenAI: GPT-5.2 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond88 / 91
MATH / AIME89 / 96
SWE-bench Verified68 / 74
Humanity's Last Exam24 / 28
Terminal-Bench48 / 65

Right-hand figures read OpenAI: GPT-5.1 / OpenAI: GPT-5.2. OpenAI: GPT-5.1 leads on 0 of 5, OpenAI: GPT-5.2 on 5.

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.

MetricOpenAI: GPT-5.1OpenAI: GPT-5.2
Text Arena 1,422 1,411
Text Arena (style controlled) 1,439 1,434
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.

MetricOpenAI: GPT-5.1OpenAI: GPT-5.2
Input $/1M $1.25 $1.75
Output $/1M $10.00 $14.00
Blended $/1M $3.44 $4.81
Cache read $/1M $0.125 $0.175
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.

MetricOpenAI: GPT-5.1OpenAI: GPT-5.2
Context window 400k 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.

MetricOpenAI: GPT-5.1OpenAI: GPT-5.2
Output tokens/s 62 54
Time to first token 1.3s 2.5s
The Known Good

Providers

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

2 hosts · 2 serve both
Full provider benchmarks →
Provider OpenAI: GPT-5.1 blendedOpenAI: GPT-5.1 tok/s OpenAI: GPT-5.2 blendedOpenAI: GPT-5.2 tok/s
OpenAI · first party $1.72 82 $2.41 49
Azure · first party $3.44 58 $4.81 43

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 →