Gemini vs ChatGPT — API Pricing Comparison

Compare Google Gemini and OpenAI ChatGPT models side by side. Interactive calculator shows exact costs for your usage pattern.

Pricing data verified: May 14, 2026

Cheapest Model
Gemini
Flash Lite at $0.075/M input
Best Context Window
Gemini
1M tokens on all models
Mid-Tier Price
Tie
Both $1.25/$10 per 1M tokens

All Models Compared

Every Gemini and ChatGPT model, ranked by input price.

Model Provider Tier Input (per 1M) Output (per 1M) Context
Gemini 2.0 Flash Lite Google Budget $0.075 $0.30 1M
Gemini 2.0 Flash Google Budget $0.10 $0.40 1M
GPT-4o mini OpenAI Budget $0.15 $0.60 128K
GPT-5 mini OpenAI Budget $0.25 $2.00 272K
Gemini 2.5 Pro Google Mid $1.25 $10.00 1M
GPT-5 OpenAI Premium $1.25 $10.00 272K
Gemini 3.1 Pro Google Mid $2.00 $12.00 1M
GPT-4o OpenAI Mid $2.50 $10.00 128K
GPT-5.5 OpenAI Premium $5.00 $30.00 1M

Calculate Your Exact Costs

Pick your Gemini and ChatGPT models, enter your usage, see the comparison.

vs
OpenAI
GPT-5
$0.00
per month
Input cost $0.00
Output cost $0.00
Per request $0.00
Google
Gemini 2.5 Pro
$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?

High-Volume Chatbot

Millions of messages, short responses. Cost per message is critical.

Pick Gemini: Flash Lite at $0.075/M is half the price of GPT-4o mini. At 10M requests/month: $22.50 vs $45.

Code Generation

Complex reasoning, longer outputs. Quality and accuracy matter.

Pick ChatGPT: GPT-5 at $1.25/$10 matches Gemini 2.5 Pro pricing but has stronger coding benchmarks in many evaluations.

Long Document Analysis

Processing 500K+ token documents. Context window is the bottleneck.

Pick Gemini: Flash at $0.10/M with 1M context. GPT-4o mini only has 128K and costs more.

Data Classification

Simple categorization at massive scale. Budget is tight.

Pick Gemini: Flash Lite at $0.075/$0.30 is the cheapest production model available. 2x cheaper than GPT-4o mini.

RAG Pipeline

Retrieval-augmented generation with long context windows.

Pick Gemini: Flash with 1M context at $0.10/M handles large retrieved contexts at a fraction of the cost.

Multi-Model Pipeline

Route tasks to the best model for each job.

Use both: Gemini Flash Lite for volume + GPT-5 for reasoning. Average cost under $0.50/M tokens.

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Frequently Asked Questions

Is Gemini or ChatGPT cheaper for API usage?

Google Gemini is significantly cheaper at the budget tier. Gemini 2.0 Flash Lite ($0.075/$0.30 per 1M tokens) is the cheapest model in the entire market — half the price of GPT-4o mini ($0.15/$0.60). At the mid tier, Gemini 2.5 Pro ($1.25/$10) matches GPT-5 ($1.25/$10) exactly. Gemini's key advantage is 1M context windows even on budget models.

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

Gemini 2.0 Flash Lite at $0.075/$0.30 per 1M tokens is the cheapest model available from any major provider. GPT-4o mini costs $0.15/$0.60 — exactly 2x more on both input and output. For high-volume workloads, Gemini Flash Lite offers the best value in the market.

Which has a bigger context window: Gemini or ChatGPT?

Gemini wins on context windows across all tiers. Gemini 2.0 Flash and Flash Lite both support 1M tokens. Gemini 2.5 Pro also supports 1M. ChatGPT's largest is GPT-5 at 272K and GPT-5.5 at 1M. For budget models, Gemini offers 8x the context of GPT-4o mini (128K) at a lower price.

Gemini 2.5 Pro vs GPT-5: which should I choose?

Both cost $1.25/$10 per 1M tokens — identical pricing. The difference is context window: Gemini 2.5 Pro offers 1M tokens vs GPT-5's 272K. For long-context tasks, Gemini is the clear winner. For tasks under 272K, choose based on quality benchmarks for your specific use case.

Can I use both Gemini and ChatGPT in the same application?

Yes. A common strategy: use Gemini Flash Lite ($0.075/M) for high-volume simple tasks, GPT-5 or Gemini 2.5 Pro ($1.25/M) for complex reasoning, and Claude Sonnet 4.6 ($3/M) for long-context analysis. This multi-model approach typically costs under $1/M tokens average — 60% less than using a single premium model.

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