DeepSeek vs ChatGPT. Price, context and when to switch.
ChatGPT is OpenAI's app; building on it means OpenAI's API, billed per token. Here is DeepSeek V4.1-Flash against GPT-6.1 Sol, one of OpenAI's current flagship API models.
Side by side.
GPT-6.1 Sol at OpenAI's list price as of October 11, 2026. Open models at OpenRelay's current rates.
| Spec | GPT-6.1 Sol | DeepSeek V4.1-Flash |
|---|---|---|
| Developer | OpenAI | DeepSeek |
| Weights | Closed | Open |
| Context window | 1.05M | 384K |
| Input | Text, images | Text, images |
| Input / 1M tokens | $2.00 | $0.15 |
| Cached input / 1M | $0.10 | $0.006 |
| Output / 1M tokens | $10.00 | $1.10 |
Monthly cost on common workloads.
100,000 requests a month at realtime rates. Token counts are typical sizes; open any row in the calculator to use your own.
Open the calculator| Workload | GPT-6.1 Sol | DeepSeek V4.1-Flash |
|---|---|---|
| Record matching2,500 in · 150 out | $650.00 | $54.0012x cheaper |
| Classification400 in · 20 out | $100.00 | $8.2012x cheaper |
| Data extraction1,500 in · 300 out | $600.00 | $55.5011x cheaper |
| Support chat3,000 in · 400 out · 50% cached | $715.00 | $67.4011x cheaper |
| RAG answers6,000 in · 500 out · 20% cached | $1,472 | $127.7212x cheaper |
| Agent step20,000 in · 1,500 out · 80% cached | $2,460 | $234.6010x cheaper |
Pick DeepSeek V4.1-Flash for
- High-volume work where the token bill dominates: extraction, classification, matching, summarization.
- Agent loops that read far more than they write: 8B parameters are active per prompt token, 16B per generated one.
- You want the option to self-host later. The weights are MIT-licensed.
Pick GPT-6.1 Sol for
- Prompts over 384K tokens. GPT-6.1 Sol takes 1.05M; this DeepSeek endpoint serves 384K.
- Tasks where your own evals show GPT-6.1 Sol ahead by enough to pay for the gap.
Questions
Is DeepSeek V4.1-Flash cheaper than GPT-6.1 Sol?
Per token, yes. GPT-6.1 Sol lists at $2.00 input and $10.00 output per 1M tokens (as of October 11, 2026). A million record-matching calls a month at 2,500 input and 150 output tokens cost $6,500 on it. DeepSeek V4.1-Flash lists at $0.15 input and $1.10 output per 1M tokens, and runs the same job for $540.00.
Is the ChatGPT app the same as the OpenAI API?
No. The app is a subscription with its own tools on top. The API bills per token for the models themselves, which is what this page compares.
Does DeepSeek V4.1-Flash work with the OpenAI SDK?
Yes. Change the base URL and the key, and set the model id:
from openai import OpenAI
client = OpenAI(
base_url="https://inference.openrelay.inc/v1",
api_key="or_...", # your OpenRelay key
)
resp = client.chat.completions.create(
model="openrelay/deepseek-v4.1-flash",
messages=[{"role": "user", "content": "Hello"}],
)How should I compare quality?
Take a few hundred real requests where you already know the right answer, run them on both models, and score the outputs the same way. Then divide cost by the share each model gets right. That number, cost per correct answer, is the one to decide on.
Price your own workload.
Your token counts and volume, every model side by side.