GPT-5 vs Gemini 3.5 Flash — AI Model Pricing Comparison 2026

Requests per Day

Days per Month

OpenAI

GPT-5

$0.00

per month

Input cost

Output cost

Cost per request

Requests/month

Google

Gemini 3.5 Flash

$0.00

per month

Input cost

Output cost

Cost per request

Requests/month

Which Model for Which Use Case?

SaaS Chatbot

High-volume customer-facing chat with short responses. GPT-5's cheaper input ($1.25 vs $1.50) makes it better for chatbot workloads with many input tokens.

Better value: GPT-5

Content Generation at Scale

Blog posts, marketing copy, long-form content. Gemini 3.5 Flash's cheaper output ($9 vs $10) makes it better for output-heavy content tasks.

Better value: Gemini 3.5 Flash

Code Assistant

Code generation, review, and refactoring. Both models handle code well. GPT-5's cheaper input gives it a slight edge for code-heavy workloads.

Slight edge: GPT-5

Data Analysis

Processing large datasets, generating insights, and creating reports. Similar pricing — choose based on your input/output ratio.

Depends on workload — use the calculator above

Not sure which model is right?

APIpulse compares all 88 models, saves scenarios, and finds the cheapest option for your exact usage pattern.

88 models across 10 providers

Save up to 10 scenarios

Export PDF cost reports

Optimize — save up to 40%

Free Tools →

Frequently Asked Questions

How much cheaper is Gemini 3.5 Flash than GPT-5?

Gemini 3.5 Flash costs $1.50/$9 per 1M tokens while GPT-5 costs $1.25/$10 per 1M tokens. GPT-5 is 17% cheaper on input but Gemini 3.5 Flash is 10% cheaper on output. For input-heavy workloads, GPT-5 is cheaper. For output-heavy workloads, Gemini 3.5 Flash wins.

Which has a larger context window?

Both models have a 1M token context window, making them equally capable for processing long documents and conversations. Neither has an advantage in context length.

When should I choose GPT-5 over Gemini 3.5 Flash?

Choose GPT-5 when you need: (1) Maximum OpenAI quality for complex tasks, (2) Input-heavy workloads where GPT-5's $1.25 input beats Gemini's $1.50, (3) Enterprise reliability from OpenAI's infrastructure. Choose Gemini 3.5 Flash for output-heavy workloads where it's 10% cheaper.

Can I mix GPT-5 and Gemini 3.5 Flash to optimize costs?

Yes. Route input-heavy tasks to GPT-5 ($1.25 input) and output-heavy tasks to Gemini 3.5 Flash ($9 output). This mixed strategy can save 10-20% while maintaining quality across both models.