Gemini API vs OpenAI API: Pricing and Capability

Google Gemini API vs the alternative at a glance

Google's Gemini API is the only one of these two APIs with pricing we can verify in detail, so this comparison leans on what's documented for Gemini and flags where OpenAI data is missing. Gemini is notable for being the only major provider with a genuinely free tier for development, alongside paid models like Gemini 3.5 Flash and Flash-Lite priced per million tokens. OpenAI's API competes in the same space, but its specific pricing isn't in the fact sheet used to write this page.

Pricing compared

Gemini's free tier gives limited access to certain models with free input and output tokens, plus Google AI Studio access, so there's no billing setup required to start experimenting. The catch is that free tier content is used to improve Google's products, which rules it out for confidential data.

On paid usage, Gemini 3.5 Flash costs $1.50 per million input tokens and $9.00 per million output tokens, while Gemini 3.5 Flash-Lite drops to $0.30 per million input tokens and $2.50 per million output tokens — among the cheapest per-token rates of any hosted frontier-lab model. Gemini 2.5 Pro has no single public price; it's listed as $1.25 to $2.50 per million input tokens and $10.00 to $15.00 per million output tokens, depending on whether the prompt is under or over 200k tokens. Some prices also vary by input type across text, image, video, and audio, which makes cost forecasting harder than a flat per-token rate. Worth flagging too: Gemini 3.7 and 3.6 Flash carry promotional pricing through December 31, 2026, that doubles starting January 1, 2027.

OpenAI's API pricing isn't included in the fact sheet used for this page, so we can't state a specific number for its models without guessing. If exact OpenAI pricing is what you're deciding on, check the vendor's own pricing page directly.

Where Google Gemini API is stronger

The free tier is the standout advantage: Gemini is the only major provider with a free tier you can actually build against rather than a one-off trial credit, and Google AI Studio access comes bundled in, so there's no billing setup to start testing. For a developer prototyping before committing budget, that's a real, documented head start.

On paid usage, Flash-Lite's per-token pricing is aggressive — $0.30 per million input tokens is among the cheapest rates of any hosted frontier-lab model, which matters a lot for high-volume, latency-sensitive workloads where cost per call adds up fast. If you're weighing raw cost across providers for something like a coding assistant backend, our best LLM API for coding tasks roundup is a useful next read, and our LLM API cost calculator lets you model actual spend across providers.

Where the alternative is stronger

OpenAI's API is one of the most widely adopted in the industry, with broad tooling and ecosystem support built around it. Without verified pricing in our fact sheet, though, we can't make a specific cost claim for OpenAI here — doing so would mean stating a number we haven't checked, which is exactly the kind of unverified figure this page is trying to avoid.

If you're evaluating OpenAI's API directly, pull current per-token pricing from the vendor's own page rather than trusting a secondhand number, since API pricing across this category changes frequently as new models ship and older comparisons often quote rates that have since been revised. For a routing-based alternative to going direct with either provider, our OpenRouter vs OpenAI API comparison is worth reading alongside this one, and it may resolve the pricing-uncertainty problem entirely if a router's published rates are what you actually want to compare against Gemini.

Which one should you pick?

Pick Google's Gemini API if you want a genuinely free tier to prototype against, aggressive per-token pricing on Flash-Lite, and documented rates you can budget from today. That combination is fully verified here and gives you a real starting point without guessing at a competitor's numbers.

Hold off on picking OpenAI's API based on price alone until you've confirmed its current per-token rates yourself, since none of its numbers are in the fact sheet backing this page. If capability rather than price is the deciding factor for your use case, that's a separate question from cost — but don't let an unverified price tip the decision either way.

The honest summary: Gemini is the only side of this comparison with checked pricing, and its free tier plus cheap Flash-Lite rates make it easy to start building without financial risk. OpenAI's API may be the better fit for your specific workload, but that claim can't be priced from the data available for this page — confirm it with the vendor before deciding, and don't let a secondhand number stand in for a real check of the current pricing page.