The Known Good Updated 8 Oct 2026 Subscribe
DeepSeek: DeepSeek V4 Pro 0423 vs OpenAI: GPT-5.5 ·DeepSeek vs OpenAI

DeepSeek: DeepSeek V4 Pro 0423 vs OpenAI: GPT-5.5 — head-to-head comparison

DeepSeek: DeepSeek V4 Pro 0423 profile OpenAI: GPT-5.5 profile All comparisons
DeepSeek: DeepSeek V4 Pro 0423 — DeepSeek
Quality
#3 of 65
93based on 3 of 7 evaluations
Known Good Index
Speed
#255 of 356
47.1
Output tokens per second
Price
#146 of 504
$0.36
Blended per 1M tokens
In $0.29 · Out $0.57
Cache hit price
#92 of 384
$0.024
per 1M tokens (−92%)
Context
#57 of 550
1.05M
tokens (~1,600 pages)
OpenAI: GPT-5.5 — OpenAI
Quality
#5 of 65
93based on 3 of 7 evaluations
Known Good Index
Speed
#128 of 356
80.8
Output tokens per second
Price
#473 of 504
$11.25
Blended per 1M tokens
In $5.00 · Out $30.00
Cache hit price
#347 of 384
$0.50
per 1M tokens (−90%)
Context
#38 of 550
1.05M
tokens (~1,600 pages)
Summary

On the Known Good Index, DeepSeek: DeepSeek V4 Pro 0423 scores 93 and OpenAI: GPT-5.5 scores 93, which puts them level. They share 2 published evaluations, with DeepSeek: DeepSeek V4 Pro 0423 ahead on 2 and OpenAI: GPT-5.5 ahead on 0.

Blended pricing is $0.36 per 1M tokens for DeepSeek: DeepSeek V4 Pro 0423 and $11.25 for OpenAI: GPT-5.5 — DeepSeek: DeepSeek V4 Pro 0423 is about 31.3× cheaper.

Throughput is 47 tokens per second for DeepSeek: DeepSeek V4 Pro 0423 and 81 for OpenAI: GPT-5.5, with time to first token at 2.0s and 4.2s. DeepSeek: DeepSeek V4 Pro 0423 accepts 1.05M tokens of context against 1.05M.

DeepSeek: DeepSeek V4 Pro 0423 is open weights under Open weights (unrestricted); OpenAI: GPT-5.5 is proprietary. 25 tracked hosts serve one or both, and 1 serve both.

Generated from tracked data on 8 Oct 2026 · how these comparisons are computed →

At a glance
MetricDeepSeek: DeepSeek V4 Pro 0423OpenAI: GPT-5.5
Known Good Index 93 based on 3 of 7 evaluations 93 based on 3 of 7 evaluations
Blended $/1M $0.36 $11.25
Output tok/s 47 81
Context window 1.05M 1.05M
Providers 23 3
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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.

MetricDeepSeek: DeepSeek V4 Pro 0423OpenAI: GPT-5.5
Known Good Index 93 93
Openness Index 60 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = DeepSeek: DeepSeek V4 Pro 0423 · marker = OpenAI: GPT-5.5 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond91 / 91
Mock AIME 2024–2597 / 84

Right-hand figures read DeepSeek: DeepSeek V4 Pro 0423 / OpenAI: GPT-5.5. DeepSeek: DeepSeek V4 Pro 0423 leads on 2 of 2, OpenAI: GPT-5.5 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.

MetricDeepSeek: DeepSeek V4 Pro 0423OpenAI: GPT-5.5
Text Arena 1,451 1,467
Text Arena (style controlled) 1,458 1,477
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.

MetricDeepSeek: DeepSeek V4 Pro 0423OpenAI: GPT-5.5
Input $/1M $0.29 $5.00
Output $/1M $0.57 $30.00
Blended $/1M $0.36 $11.25
Cache read $/1M $0.024 $0.500
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.

MetricDeepSeek: DeepSeek V4 Pro 0423OpenAI: GPT-5.5
Context window 1.05M 1.05M
Max output tokens 384k 128k
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.

MetricDeepSeek: DeepSeek V4 Pro 0423OpenAI: GPT-5.5
Output tokens/s 47 81
Time to first token 2.0s 4.2s
The Known Good

Providers

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

25 hosts · 1 serve both
Full provider benchmarks →
Provider DeepSeek: DeepSeek V4 Pro 0423 blendedDeepSeek: DeepSeek V4 Pro 0423 tok/s OpenAI: GPT-5.5 blendedOpenAI: GPT-5.5 tok/s
BaseTen $2.17 122 — —
Azure · first party $2.39 102 $11.25 59
Relace $1.26 86 — —
Baidu · first party $0.36 58 — —
Reka · first party $3.41 56 — —
CoreWeave $1.50 55 — —
Novita $2.00 55 — —
Alibaba · first party $1.77 53 — —
Cloudflare $1.50 51 — —
DigitalOcean $1.30 49 — —
NextBit $2.17 45 — —
SiliconFlow $1.91 44 — —
AtlasCloud $2.10 43 — —
DeepInfra $1.62 43 — —
GMICloud $1.20 42 — —
Together $2.17 39 — —
Venice $2.06 38 — —
Ionstream $1.41 35 — —
StreamLake $0.36 35 — —
DeepSeek · first party $0.99 31 — —
Parasail $1.21 31 — —
Wafer $1.50 28 — —
Fireworks $1.20 — — —
Amazon Bedrock · first party — — $12.38 92
OpenAI · first party — — $5.62 72

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 →