DeepSeek V4 Pro vs GPT-5.5: which is better for agents?

GPT-5.5 scores higher on output quality (7.6/10 vs 7.2/10), while DeepSeek V4 Pro is the cheaper option. DeepSeek V4 Pro is best for self-hosted setups that want DeepSeek's larger V4 model; GPT-5.5 is best for existing GPT-5.5 setups on an API key until they move to GPT-6.1 Sol. Live community votes on this page show what people actually prefer.

Is DeepSeek V4 Pro cheaper than GPT-5.5?

DeepSeek V4 Pro is cheaper: roughly $0.56 vs $13 per 1M tokens (blended). DeepSeek V4 Pro: $0.43 in · $0.85 out / 1M tokens. GPT-5.5: $5.00 in · $30 out / 1M tokens.

Can I switch between DeepSeek V4 Pro and GPT-5.5 in the same agent?

Yes. Model-agnostic agents (Cline, Aider, OpenClaw, Hermes Agent, Kilo Code, OpenCode) let you swap models per task. Many people route hard tasks to the stronger model and routine work to the cheaper one.

DeepSeek V4 Pro vs GPT-5.5: Which AI Model Is Better? (2026)

Community vote

Pick a winner in each dimension. You can change your vote any time.

Output Quality

Correctness and depth of what it produces

Agentic Ability

Tool calls, instruction-following, and multi-step tasks

Speed

Tokens per second and time-to-first-token

Value for Money

How much capability you get per dollar

Reliability

Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec

DeepSeek V4 Pro

GPT-5.5

Maker

DeepSeek

OpenAI

Blended price / 1M

$0.56

$13

Input / output

$0.43 in · $0.85 out / 1M tokens

$5.00 in · $30 out / 1M tokens

Context window

1.0M

1.1M

Open weights

Yes

Tool use

Yes

Reasoning

Yes

Output Quality

7.2

7.6

Agentic Ability

6.1

6.2

Speed

7.7

7.8

Value for Money

6.1

4.0

Reliability

8.7

8.8

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: DeepSeek V4 Pro or GPT-5.5?

Updated 2026-10-17

Choose DeepSeek V4 Pro if you want self-hosted setups that want DeepSeek's larger V4 model. Choose GPT-5.5 if you want existing GPT-5.5 setups on an API key until they move to GPT-6.1 Sol.

In our editorial scoring, GPT-5.5 leads in 4 of five dimensions (output quality, agentic ability, speed and reliability), while DeepSeek V4 Pro leads in 1. On price, DeepSeek V4 Pro runs about $0.56 per 1M tokens (blended) and is open-weight; GPT-5.5 is about $13 and proprietary.

Where DeepSeek V4 Pro falls short