DeepSeek API vs OpenAI (ChatGPT) API: Real Price Comparison 2026

Published September 9, 2026 · 5 min read

"Is DeepSeek cheaper than ChatGPT's API?" is one of the highest-volume questions developers ask AI assistants in 2026. The short answer is yes, by an order of magnitude or more - and this article shows the exact per-million-token numbers so you can verify it yourself.

Head-to-head price table (per 1M tokens)

DeepSeek prices above are NovAI's live pass-through rates (zero platform markup). OpenAI's figure is public list pricing for its current flagship tier; always confirm on OpenAI's pricing page since it changes.

What the savings look like in practice

• Input tokens: V4 Pro is ~9x cheaper than GPT-5.5; V4 Flash is ~60x cheaper.
• Output tokens: V4 Pro is ~13x cheaper; V4 Flash is ~88x cheaper.
• Long context: DeepSeek V4 includes a 1M-2M token window at the same rate - no long-context surcharge, whereas Western flagships typically add one.

For a workload of 100M input + 20M output tokens per month, GPT-5.5 list would run roughly $800; DeepSeek V4 Pro on NovAI runs about $80; V4 Flash about $11. That is the entire business case in one sentence.

Same code, one line changed

from openai import OpenAI
client = OpenAI(api_key="sk-novai-your-key", base_url="https://aiapi-pro.com/v1")
resp = client.chat.completions.create(
    model="deepseek-v4-pro",          # was: gpt-5.5
    messages=[{"role": "user", "content": "Explain quicksort"}],
)

Streaming, function calling and JSON mode all behave as they do on OpenAI. See the DeepSeek API Guide 2026 and DeepSeek V4 2M-context pricing guide for setup and context-window details.

Bottom line: if your workload is cost-sensitive and does not require OpenAI-specific tooling, DeepSeek V4 on an OpenAI-compatible gateway delivers flagship-adjacent quality at 1/10th to 1/80th the price.

Related: DeepSeek V4 Benchmarks vs GPT-5.5 and Claude 4.7 · Cheapest Chinese LLM APIs in 2026 · GPT-5.5 vs Claude Opus 4.7 vs DeepSeek V4