The Known Good Updated 29 Jul 2026
OpenAI: GPT-5.4 vs OpenAI: gpt-oss-120b ·OpenAI vs OpenAI

OpenAI: GPT-5.4 vs OpenAI: gpt-oss-120b — head-to-head comparison

OpenAI: GPT-5.4 profile OpenAI: gpt-oss-120b profile All comparisons
OpenAI: GPT-5.4 — OpenAI
Quality
#10 of 62
90based on 5 of 7 evaluations
Known Good Index
Speed
#90 of 317
68.0
Output tokens per second
Price
#328 of 370
$5.62
Blended per 1M tokens
In $2.50 · Out $15.00
Cache hit price
#192 of 238
$0.25
per 1M tokens (−90%)
Context
#17 of 375
1.05M
tokens (~1,600 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, OpenAI: GPT-5.4 scores 90 and OpenAI: gpt-oss-120b scores 61 — a 29-point lead for OpenAI: GPT-5.4. They share 3 published evaluations, with OpenAI: GPT-5.4 ahead on 3 and OpenAI: gpt-oss-120b ahead on 0.

Blended pricing is $5.62 per 1M tokens for OpenAI: GPT-5.4 and $0.07 for OpenAI: gpt-oss-120b — OpenAI: gpt-oss-120b is about 80.1× cheaper.

Throughput is 68 tokens per second for OpenAI: GPT-5.4 and 145 for OpenAI: gpt-oss-120b, with time to first token at 2.5s and 0.9s. OpenAI: GPT-5.4 accepts 1.05M tokens of context against 131k.

OpenAI: GPT-5.4 is proprietary; OpenAI: gpt-oss-120b is open weights under Open weights (unrestricted). 19 tracked hosts serve one or both.

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

At a glance
MetricOpenAI: GPT-5.4OpenAI: gpt-oss-120b
Known Good Index 90 based on 5 of 7 evaluations 61 based on 3 of 7 evaluations
Blended $/1M $5.62 $0.07
Output tok/s 68 145
Context window 1.05M 131k
Providers 2 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.

MetricOpenAI: GPT-5.4OpenAI: gpt-oss-120b
Known Good Index 90 61
Coding Index 89
Mathematics Index 98 89
Reasoning Index 88
Agentic Index 89 18
Openness Index 5 60
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = OpenAI: GPT-5.4 · marker = OpenAI: gpt-oss-120b · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond93 / 76
Mock AIME 2024–2598 / 89
Terminal-Bench82 / 19

Right-hand figures read OpenAI: GPT-5.4 / OpenAI: gpt-oss-120b. OpenAI: GPT-5.4 leads on 3 of 3, OpenAI: gpt-oss-120b 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.

MetricOpenAI: GPT-5.4OpenAI: gpt-oss-120b
Text Arena 1,452 1,366
Text Arena (style controlled) 1,465 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.

MetricOpenAI: GPT-5.4OpenAI: gpt-oss-120b
Input $/1M $2.50 $0.04
Output $/1M $15.00 $0.17
Blended $/1M $5.62 $0.07
Cache read $/1M $0.250 $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.

MetricOpenAI: GPT-5.4OpenAI: gpt-oss-120b
Context window 1.05M 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.

MetricOpenAI: GPT-5.4OpenAI: gpt-oss-120b
Output tokens/s 68 145
Time to first token 2.5s 0.9s
The Known Good

Providers

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

19 hosts
Full provider benchmarks →
Provider OpenAI: GPT-5.4 blendedOpenAI: GPT-5.4 tok/s OpenAI: gpt-oss-120b blendedOpenAI: gpt-oss-120b tok/s
Azure · first party $5.62 59
OpenAI · first party $2.81 59
Cerebras $0.45 501
SambaNova $0.34 367
Groq $0.26 352
Amazon Bedrock · first party $0.26 342
Nebius $0.26 231
DeepInfra $0.07 196
Google · first party $0.16 177
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 →