Decision comparison
Gemini API vs OpenAI
Both are foundation-model APIs billed per 1M input and output tokens, so the deciding questions are which model you need, how its rate will move, and how you want to buy capacity. On the Gemini API a mid-tier model, Gemini 3.8 Flash, costs $0.75 input and $3.75 output per 1M tokens through December 31, 2026 and twice that from January 1, 2027; OpenAI's GPT-5.4 mini costs $0.75 and $4.50 at its quoted standard rates. For 10M input and 2M output tokens a month that is 10 x $0.75 + 2 x $3.75 = $15.00 on Gemini 3.8 Flash ($30.00 from January 2027) and 10 x $0.75 + 2 x $4.50 = $16.50 on GPT-5.4 mini, before tools, caching and taxes. The models are not equivalent, so price the one you would actually ship. Google adds a free tier, separately priced Batch, Flex and Priority processing and a documented path for code written against the OpenAI libraries.
Direct comparison. These are reviewed substitutes bought for the same job, so the differences below are the ones that decide between them.
All 2 are foundation model providers.
Quick Comparison
| Decision factor | Gemini API | OpenAI |
|---|---|---|
| Best for | Teams that want Google's Gemini models through a developer API with a free tier for prototyping, separately priced Batch, Flex and Priority processing, and a route to Google Cloud for enterprise controls. | Teams building on OpenAI's GPT models through the OpenAI API, using its official Python and JavaScript libraries, with ChatGPT's consumer and business plans sold separately from API usage. |
| Pricing model | Free tier: free input and output tokens on some models, with lower rate limits, Google AI Studio access, and content used to improve Google's products. Paid tier: billed in USD per 1M tokens by model, with input and output priced separately; for example Gemini 4 Argon is $2.00 input and $10.00 output through November 30, 2026, rising to $4.00 and $20.00 on December 1, 2026. The Batch API costs 50% less. Enterprise: contact sales, through Google Cloud's Gemini Enterprise Agent Platform. Official pricing page checked October 26, 2026. | Contact for pricing OpenAI API standard-tier prices per 1M tokens (short context): GPT-5.6 Sol $4.00 input and $20.00 output, GPT-5.6 Terra $2.00 and $12.00, GPT-5.6 Luna $0.20 and $1.20. GPT-5.4 mini is $0.75 input and $4.50 output, GPT-5.4 nano $0.20 and $1.25, and GPT-4o mini $0.15 and $0.60. Verified 2026-10-05 against https://developers.openai.com/api/docs/pricing. |
| Free access | A Free tier gives limited access to certain models with free input and output tokens and Google AI Studio, which is free of charge in all available regions. Content sent on the Free tier is used to improve Google's products, and Gemini 4 Argon is not offered on it. | API usage is billed per token. ChatGPT has a Free plan for everyday use, but it is a separate product from API usage. |
| Processing options | Standard, Batch, Flex and Priority processing, each priced per model. The Batch API is listed at a 50% cost reduction: Gemini 4 Argon Batch is $1.00 input and $5.00 output per 1M tokens through November 30, 2026, and Priority is $3.60 and $18.00. | OpenAI lists standard processing rates per model; GPT-5.6 Terra's quoted rates apply to prompts up to 272K input tokens. |
| Developer tooling | Google Gen AI SDKs for Python, JavaScript, Java and Go, plus REST. The Interactions API has been the default interface since June 2026; generateContent is still supported but legacy. Google also documents access to Gemini models through the OpenAI Python and JavaScript libraries. | The official Python library openai/openai-python (Apache-2.0) and the openai npm package, plus the Realtime API for voice and live experiences. |
| Data use and enterprise route | Paid-tier content is not used to improve Google's products. Enterprise deployments run through Gemini Enterprise Agent Platform, with optional dedicated support, provisioned throughput and usage-based volume discounts; Google notes its prices may differ from the Gemini API's. | Enterprise API terms are arranged with OpenAI's sales team; ChatGPT business and enterprise plans are priced separately from API usage. |
Gemini API
- Best for:
- Teams that want Google's Gemini models through a developer API with a free tier for prototyping, separately priced Batch, Flex and Priority processing, and a route to Google Cloud for enterprise controls.
- Pricing model:
- Free tier: free input and output tokens on some models, with lower rate limits, Google AI Studio access, and content used to improve Google's products. Paid tier: billed in USD per 1M tokens by model, with input and output priced separately; for example Gemini 4 Argon is $2.00 input and $10.00 output through November 30, 2026, rising to $4.00 and $20.00 on December 1, 2026. The Batch API costs 50% less. Enterprise: contact sales, through Google Cloud's Gemini Enterprise Agent Platform. Official pricing page checked October 26, 2026.
- Free access:
- A Free tier gives limited access to certain models with free input and output tokens and Google AI Studio, which is free of charge in all available regions. Content sent on the Free tier is used to improve Google's products, and Gemini 4 Argon is not offered on it.
- Processing options:
- Standard, Batch, Flex and Priority processing, each priced per model. The Batch API is listed at a 50% cost reduction: Gemini 4 Argon Batch is $1.00 input and $5.00 output per 1M tokens through November 30, 2026, and Priority is $3.60 and $18.00.
- Developer tooling:
- Google Gen AI SDKs for Python, JavaScript, Java and Go, plus REST. The Interactions API has been the default interface since June 2026; generateContent is still supported but legacy. Google also documents access to Gemini models through the OpenAI Python and JavaScript libraries.
- Data use and enterprise route:
- Paid-tier content is not used to improve Google's products. Enterprise deployments run through Gemini Enterprise Agent Platform, with optional dedicated support, provisioned throughput and usage-based volume discounts; Google notes its prices may differ from the Gemini API's.
OpenAI
- Best for:
- Teams building on OpenAI's GPT models through the OpenAI API, using its official Python and JavaScript libraries, with ChatGPT's consumer and business plans sold separately from API usage.
- Pricing model:
- Contact for pricing OpenAI API standard-tier prices per 1M tokens (short context): GPT-5.6 Sol $4.00 input and $20.00 output, GPT-5.6 Terra $2.00 and $12.00, GPT-5.6 Luna $0.20 and $1.20. GPT-5.4 mini is $0.75 input and $4.50 output, GPT-5.4 nano $0.20 and $1.25, and GPT-4o mini $0.15 and $0.60. Verified 2026-10-05 against https://developers.openai.com/api/docs/pricing.
- Free access:
- API usage is billed per token. ChatGPT has a Free plan for everyday use, but it is a separate product from API usage.
- Processing options:
- OpenAI lists standard processing rates per model; GPT-5.6 Terra's quoted rates apply to prompts up to 272K input tokens.
- Developer tooling:
- The official Python library openai/openai-python (Apache-2.0) and the openai npm package, plus the Realtime API for voice and live experiences.
- Data use and enterprise route:
- Enterprise API terms are arranged with OpenAI's sales team; ChatGPT business and enterprise plans are priced separately from API usage.
Need the cost answer?
Compare OpenAI, Anthropic and Gemini API using your workload.
Public signals
Verified factual signals only. Bars appear only for like-for-like metrics with five weekly assessments for every tool; missing evidence stays explicit. These signals do not establish enterprise adoption, product quality, or total cost.
| Metric | Gemini API | OpenAI |
|---|---|---|
| GitHub commits, 90d(Developer adoption) | 225 | 389 |
| GitHub stars(Developer adoption) | 4,000+ | 31,000+ |
| Search interest(Market interest) | Not available | 311 |
| Hacker News mentions, 90d(Community interest) | 10 | 1.8k |
| npm weekly downloads(Developer adoption) | 15.2M | 26.8M |
| PyPI weekly downloads(Developer adoption) | 38.1M | 83.9M |
| Stack Overflow questions(Community interest) | 378 | 2.5k |
| Hugging Face downloads(Product adoption) | Not available | 35.8M |
| Hugging Face likes(Product adoption) | Not available | 14.5k |
| Product Hunt comments(Community interest) | Not available | 1 |
| Product Hunt rating(Community interest) | Not available | 5.0/5 |
| Product Hunt reviews(Community interest) | Not available | 1 |
| Product Hunt votes(Community interest) | Not available | 7 |
As of October 26, 2026 — updated weekly.
Health & risk evidence
Observed public-source checks for mapped package versions and repositories.
Gemini API
October 26, 2026Package vulnerabilities
npm · @google/genai@2.31.0 · PyPI · google-genai@2.33.0
0 vulnerabilities
across 2 packages
Repository security score
Not available
OpenAI
October 26, 2026Package vulnerabilities
npm · openai@7.43.0 · PyPI · openai@3.37.0
0 vulnerabilities
across 2 packages
Repository security score
Not available
Interface Preview
Gemini API
OpenAI
Feature Comparison
| Feature | Gemini API | OpenAI |
|---|---|---|
| Models and limits | ||
| Example model context | Gemini 4 Argon: shared 1M-token context window with long decodes up to 1M tokens | GPT-5.6 Terra: 1.05M context length and 128K max output tokens |
| Rates: Gemini 3.8 Flash and GPT-5.4 mini | Gemini 3.8 Flash: $0.75 input, $3.75 output through December 31, 2026 | GPT-5.4 mini: $0.75 input, $4.50 output |
| Rates: Gemini 4 Argon and GPT-5.6 Terra | Gemini 4 Argon: $2.00 input, $10.00 output through November 30, 2026 | GPT-5.6 Terra: $2.00 input, $12.00 output up to 272K input tokens |
| Pricing terms | ||
| Scheduled price changes | Gemini 4 Argon rises to $4.00 and $20.00 on December 1, 2026; Gemini 3.8 Flash to $1.50 and $7.50 on January 1, 2027 | No scheduled change in the rates quoted here |
| Long-prompt pricing | Gemini 3.1 Pro Preview: $2.00 input up to 200k-token prompts, $4.00 above | Quoted GPT-5.6 Terra rates apply to prompts up to 272K input tokens |
| Free API usage | Free tier with free input and output tokens on certain models | API billed per token; ChatGPT Free is a separate consumer plan |
| Batch pricing | Batch API listed at a 50% cost reduction | Standard processing rates quoted here |
| Search grounding charge | 5,000 free requests a month on Gemini 3 and newer, then $14 per 1,000 | Not part of the rates quoted here |
| Developer experience | ||
| Official SDK languages | Python, JavaScript, Java and Go | Python (openai/openai-python) and JavaScript (openai on npm) |
| Prototyping console | Google AI Studio, free of charge in all available regions | OpenAI's API platform; ChatGPT is a separate product |
| Library compatibility | Gemini models are reachable through the OpenAI Python and JavaScript libraries | Native OpenAI libraries |
| Real-time voice | Live API for real-time voice agents | Realtime API |
Models and limits
Example model context
Rates: Gemini 3.8 Flash and GPT-5.4 mini
Rates: Gemini 4 Argon and GPT-5.6 Terra
Pricing terms
Scheduled price changes
Long-prompt pricing
Free API usage
Batch pricing
Search grounding charge
Developer experience
Official SDK languages
Prototyping console
Library compatibility
Real-time voice
Which to choose
Both are foundation-model APIs billed per 1M input and output tokens, so the deciding questions are which model you need, how its rate will move, and how you want to buy capacity. On the Gemini API a mid-tier model, Gemini 3.8 Flash, costs $0.75 input and $3.75 output per 1M tokens through December 31, 2026 and twice that from January 1, 2027; OpenAI's GPT-5.4 mini costs $0.75 and $4.50 at its quoted standard rates. For 10M input and 2M output tokens a month that is 10 x $0.75 + 2 x $3.75 = $15.00 on Gemini 3.8 Flash ($30.00 from January 2027) and 10 x $0.75 + 2 x $4.50 = $16.50 on GPT-5.4 mini, before tools, caching and taxes. The models are not equivalent, so price the one you would actually ship. Google adds a free tier, separately priced Batch, Flex and Priority processing and a documented path for code written against the OpenAI libraries.
Best-fit scenarios
Choose Gemini API if:
Choose the Gemini API when you want to prototype for free and then pay per token in production: the Free tier includes free input and output tokens on Gemini 3.8 Flash and Gemini 3.5 Flash-Lite, and Google AI Studio costs nothing to use. It also fits workloads that can use the Batch API, listed at a 50% cost reduction, or need Search grounding, which includes 5,000 free requests a month on Gemini 3 and newer models before $14 per 1,000. Because Google documents access to Gemini through the OpenAI libraries, a team already on OpenAI's SDK can trial Gemini without rewriting its client. The trade-off is moving prices: budget Gemini 4 Argon at $4.00 and $20.00 from December 1, 2026 and Gemini 3.8 Flash at $1.50 and $7.50 from January 1, 2027, and remember that Free-tier content is used to improve Google's products.
Choose OpenAI if:
Choose OpenAI when your application is built on GPT models and its official libraries, and you want rates that are not scheduled to change in the figures quoted here: GPT-5.4 nano at $0.20 input and $1.25 output per 1M tokens, GPT-5.4 mini at $0.75 and $4.50, and GPT-5.6 Terra at $2.00 and $12.00 with a 1.05M context length and 128K maximum output. It also suits teams that already use the Realtime API for voice experiences. The Gemini API is the better fit when you need a free API tier, Google Search grounding or Google Cloud's enterprise route; OpenAI's ChatGPT Free plan is a consumer product and does not cover API usage.
These scenarios reflect the available product evidence. Your requirements, existing stack, and team expertise should guide the final decision.
Frequently Asked Questions
Which is cheaper per token, the Gemini API or OpenAI?
It depends on the model pair, and Gemini's rates are scheduled to change. At the rates quoted here, Gemini 3.8 Flash costs $0.75 input and $3.75 output per 1M tokens through December 31, 2026 ($1.50 and $7.50 from January 1, 2027), and GPT-5.4 mini costs $0.75 and $4.50. OpenAI's GPT-5.4 nano is $0.20 and $1.25. Price the specific model you plan to ship at its future rate.
Can I use the OpenAI SDK to call Gemini models?
Yes. Google documents that Gemini models are accessible using the OpenAI libraries for Python and TypeScript/JavaScript along with the REST API, and it recommends calling the Gemini API directly if you are not already using the OpenAI libraries.
Does either offer free API usage?
The Gemini API has a Free tier with free input and output tokens on certain models, such as Gemini 3.8 Flash and Gemini 3.5 Flash-Lite, but content sent on it is used to improve Google's products. OpenAI bills API usage per token; its ChatGPT Free plan is a separate consumer product.
Are Gemini API prices going up?
For some models, on announced dates. Gemini 4 Argon's Standard rates go from $2.00 input and $10.00 output per 1M tokens to $4.00 and $20.00 on December 1, 2026, and Gemini 3.8 Flash's from $0.75 and $3.75 to $1.50 and $7.50 on January 1, 2027.