ChatGPT vs DeepSeek — API Pricing Comparison

Compare all OpenAI and DeepSeek models side by side. DeepSeek V4 Pro is 65-91% cheaper than GPT-5, with 4x larger context window.

Pricing data verified: May 14, 2026

Cheapest Model
OpenAI
GPT-oss 20B at $0.08/M input
Best Context Window
DeepSeek
1M tokens vs GPT-5's 272K
Best Value Mid-Tier
DeepSeek
V4 Pro at $0.44/M vs GPT-5 at $1.25/M

All Models Compared

Every OpenAI and DeepSeek model, ranked by input price.

Model Provider Tier Input (per 1M) Output (per 1M) Context
GPT-oss 20B OpenAI Budget $0.08 $0.35 128K
GPT-4o mini OpenAI Budget $0.15 $0.60 128K
GPT-oss 120B OpenAI Budget $0.15 $0.60 128K
DeepSeek V4 Flash DeepSeek Budget $0.14 $0.28 1M
GPT-5 mini OpenAI Budget $0.25 $2.00 272K
DeepSeek V3 DeepSeek Budget $0.27 $1.10 128K
DeepSeek V4 Pro DeepSeek Budget $0.44 $0.87 1M
GPT-5.3 Codex OpenAI Mid $1.75 $14.00 400K
GPT-4o OpenAI Mid $2.50 $10.00 128K
GPT-5 OpenAI Premium $1.25 $10.00 272K
GPT-5.5 OpenAI Premium $5.00 $30.00 1M
GPT-5.5 Pro OpenAI Premium $30.00 $180.00 1M

Calculate Your Exact Costs

Pick your OpenAI and DeepSeek models, enter your usage, see the savings.

vs
OpenAI
GPT-5
$0.00
per month
Input cost $0.00
Output cost $0.00
Per request $0.00
DeepSeek
DeepSeek V4 Flash
$0.00
per month
Input cost $0.00
Output cost $0.00
Per request $0.00
Enter your usage above to see savings.

Which Should You Choose?

Chatbot / Customer Support

High volume, short responses. Cost per message matters most. Budget models handle most customer queries well.

Pick DeepSeek: V4 Flash at $0.14/M with 1M context is cheaper than GPT-5 mini ($0.25/M) and has 4x the context window.

Code Generation

Complex reasoning, longer outputs. Quality and accuracy matter. Both providers excel here.

Pick DeepSeek: V4 Pro at $0.44/$0.87 is 65% cheaper on input than GPT-5, with competitive coding quality and 1M context.

Long Document Analysis

Processing large documents, legal contracts, or codebases. Context window is critical.

Pick DeepSeek: V4 Pro has 1M context at $0.44/$0.87 — 4x larger than GPT-5's 272K and 65% cheaper on input.

High-Volume Data Processing

Classification, extraction, summarization at scale. Budget is tight, volume is high.

Pick OpenAI: GPT-oss 20B at $0.08/M is cheapest. At 10M requests/month: $240 vs $420 for DeepSeek V4 Flash.

Enterprise / OpenAI Ecosystem

Using Azure OpenAI, need OpenAI's enterprise features, or specific GPT capabilities.

Pick OpenAI: Azure integration, enterprise SLAs, ChatGPT ecosystem. The premium is justified for OpenAI-centric workflows.

Startup MVP / Side Project

Minimize costs while building. Need reliable API at the lowest price point.

Pick DeepSeek: V4 Flash at $0.14/M input with 1M context lets you iterate cheaply. Great for prototyping with long docs.

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Frequently Asked Questions

Is DeepSeek cheaper than ChatGPT for API usage?

Yes, DeepSeek is dramatically cheaper than OpenAI's premium models. DeepSeek V4 Pro ($0.44/$0.87 per 1M tokens) is 65% cheaper on input and 91% cheaper on output than GPT-5 ($1.25/$10.00). DeepSeek V4 Flash ($0.14/$0.28) is also cheaper than GPT-5 mini ($0.25/$2.00). However, GPT-4o mini ($0.15/$0.60) and GPT-oss 20B ($0.08/$0.35) are competitive with DeepSeek on price.

What is the cheapest ChatGPT model vs the cheapest DeepSeek model?

GPT-oss 20B at $0.08/$0.35 per 1M tokens is the cheapest OpenAI model. DeepSeek V4 Flash at $0.14/$0.28 is DeepSeek's cheapest. GPT-oss 20B is 43% cheaper on input but 25% more expensive on output. At 10M tokens/month, GPT-oss 20B costs $0.80+$3.50=$4.30 vs DeepSeek V4 Flash's $1.40+$2.80=$4.20 — nearly identical.

Does DeepSeek have the same context window as ChatGPT?

DeepSeek offers larger context windows on budget models. DeepSeek V4 Pro and V4 Flash both support 1M tokens. GPT-5 only supports 272K tokens, and GPT-5 mini also 272K. GPT-4o supports 128K. For long-document workloads, DeepSeek has a significant advantage with 1M context at budget prices.

GPT-5 vs DeepSeek V4 Pro: which should I choose?

DeepSeek V4 Pro is 65% cheaper on input ($0.44 vs $1.25) and 91% cheaper on output ($0.87 vs $10.00), with nearly 4x larger context window (1M vs 272K). Choose DeepSeek V4 Pro for cost-sensitive workloads, high-volume processing, and startups. Choose GPT-5 when you need OpenAI's ecosystem, specific GPT capabilities, or enterprise compliance.

Is DeepSeek as good as GPT-5 for code generation?

DeepSeek V4 Pro performs competitively on coding benchmarks at a fraction of the cost. For most code generation tasks, DeepSeek delivers comparable quality. GPT-5 may have an edge on complex reasoning tasks. The best approach: start with DeepSeek V4 Pro for cost savings, and use GPT-5 only for tasks where quality differences matter.

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