Same price — context window is the tiebreaker
Both models cost exactly the same per token. Gemini 2.5 Pro's 1M context (vs 272K) makes it better for long-document and multi-turn workloads.
OpenAI
GPT-5
Same Price
$0.00
per month
Input cost
Output cost
Cost per request
Requests/month
Google
Gemini 2.5 Pro
Same Price + 3.7x Context
$0.00
per month
Input cost
Output cost
Cost per request
Requests/month

Which Model for Which Use Case?

Long-Document Processing

Gemini 2.5 Pro's 1M context window can process entire codebases, legal contracts, or research papers in a single request. GPT-5's 272K context requires chunking for documents over ~200K tokens.

Best value: Gemini 2.5 Pro (3.7x more context, same price)

OpenAI Ecosystem Integration

GPT-5 integrates natively with OpenAI's Assistants API, function calling, and tool-use patterns. If your stack is built on OpenAI APIs, GPT-5 provides the smoothest integration path.

Ecosystem fit: GPT-5 | Cost-neutral alternative: Gemini 2.5 Pro

Code Review & Analysis

For codebases that exceed 272K tokens, Gemini 2.5 Pro can review entire repositories in one pass. GPT-5 excels at targeted code tasks within its context limit.

Large repos: Gemini 2.5 Pro | Focused tasks: GPT-5

Multi-Turn Conversations

Chatbots with long conversation history benefit from Gemini 2.5 Pro's 1M context — it can hold ~7x more conversation turns before hitting limits. Both models cost the same per token.

Long sessions: Gemini 2.5 Pro (3.7x context)

Need deeper cost analysis?

APIpulse lets you compare all 85 models, save scenarios, and export PDF reports.

85 models across 10 providers
Save up to 10 scenarios
Export PDF cost reports
Optimize — save up to 40%
Free Tools →

Frequently Asked Questions

Is GPT-5 or Gemini 2.5 Pro cheaper?

Neither — they cost exactly the same. Both GPT-5 and Gemini 2.5 Pro charge $1.25/M input tokens and $10.00/M output tokens. At 1M input + 500K output tokens/month, both cost $6.25. The difference is context window: Gemini 2.5 Pro offers 1M tokens (3.7x more than GPT-5's 272K).

Which has a larger context window, GPT-5 or Gemini 2.5 Pro?

Gemini 2.5 Pro has a 1M token context window, which is 3.7x larger than GPT-5's 272K token window. This makes Gemini 2.5 Pro significantly better for long-document processing, large codebases, and multi-turn conversations with extensive history.

When should I choose GPT-5 over Gemini 2.5 Pro?

Choose GPT-5 when you need OpenAI ecosystem integration (ChatGPT plugins, Assistants API), have workloads that fit within 272K context, prefer OpenAI's tool-use and function-calling patterns, or need GPT-5's specific strengths in coding and reasoning. Choose Gemini 2.5 Pro when you need larger context windows, Google ecosystem integration, or multimodal capabilities.

Can I use both GPT-5 and Gemini 2.5 Pro together?

Yes. Many production systems use both models: GPT-5 for tasks that benefit from OpenAI's tool ecosystem and function calling, and Gemini 2.5 Pro for long-context tasks like document analysis and code review. APIpulse's cost calculator can model multi-model setups to optimize your budget.

📊 Live Pricing

Real-time prices for all 85 models

💰 Pricing Hub

All 85 models compared — find the cheapest

Related Comparisons

5 Cheaper Gemini Alternatives →
Save 60-97% on API costs
5 Cheaper GPT-5 Alternatives →
Save 60-97% on API costs
GPT-5 vs Gemini 3.1 Pro
Cross-provider premium
GPT-5 vs Claude Opus 4.8
Premium cross-provider
GPT-5 vs Claude Sonnet 4
Mid-tier showdown

Related Tools

Migration Checklist →
Switch providers in 5 steps
Free Pricing Widget
Embed live AI pricing on your site
Share on X LinkedIn

All Tools Are Free

No signup required to 67-model comparison, migration code snippets, PDF reports, price alerts, and cost monitoring. ✅ All tools free.

Free Tools →
This was a snapshot. What about next month?
Prices change. New models launch. Our tools catch what a one-time calculation can't — and saves you money every month.
Free Tools → 🔍 Free audit first