Head to head
Google Gemini API vs OpenAI API
As a llm API, OpenAI API rates higher on the APIbenchmarks Index, 91.9 to 87.9, a 4-point gap. Here is how they compare on each criterion.
Criterion by criterion
| Criterion | Google Gemini API | OpenAI API |
|---|---|---|
| Documentation & DX | ||
| Reliability | ||
| Ecosystem & SDKs | ||
| Accessibility | ||
| APIbenchmarks Index | 87.9 | 91.9 |
Specifications
| Google Gemini API | OpenAI API | |
|---|---|---|
| Best for | Multimodal, long-context, GCP-backed | Frontier general-purpose LLM platform |
| Free tier | Free tier on Flash models: ~1,500 req/day, 250k TPM (Pro models paid-only since Apr 2026) | No |
| Pricing | Per token | Per token |
| Official SDKs | 6 languages | 7 languages |
Is Google Gemini API better than OpenAI API?
On the APIbenchmarks Index, OpenAI API rates higher (91.9 vs 87.9). It leads on the four weighted criteria, but price is reported separately, so the best choice still depends on your budget.
Verdict in one line
OpenAI API leads by 4 points (91.9 vs 87.9) and wins 3 of 4 criteria; Google Gemini API wins 1.
Winner by criterion
| Criterion | Winner | ||
|---|---|---|---|
| Documentation & DX | 88 | 95 | |
| Reliability | 89 | 90 | |
| Ecosystem & SDKs | 85 | 98 | |
| Accessibility | 90 | 82 |
Choose Google Gemini API if… / choose OpenAI API if…
- →accessibility matters most to you (90 vs 82)
- →you want a free tier to start (Free tier on Flash models: ~1,500 req/day, 250k TPM (Pro models paid-only since Apr 2026))
- →your use case matches its focus: multimodal, long-context, gcp-backed
- →documentation & dx matters most to you (95 vs 88)
- →reliability matters most to you (90 vs 89)
- →ecosystem & sdks matters most to you (98 vs 85)
- →you need broad SDK coverage (7 official SDKs vs 6)
- →your use case matches its focus: frontier general-purpose llm platform
Pricing side by side
- Model
- Per token
- Free tier
- Free tier on Flash models: ~1,500 req/day, 250k TPM (Pro models paid-only since Apr 2026)
- Free tier (AI Studio)$0
- Gemini 2.5 Flash-Lite$0.10 / $1.50 in/out per 1M
- Gemini 2.5 Flash$0.30 / $2.50 in/out per 1M
- Gemini 2.5 Pro$1.25 / $10.00 in/out per 1M
- Grounding / tools add-on$35 per 1,000 prompts
- Model
- Per token
- Free tier
- No
- GPT-5.5 (flagship)$5.00 / $30.00 per 1M tokens
- GPT-5.4$2.50 / $15.00 per 1M tokens
- GPT-5.4-mini$0.75 / $4.50 per 1M tokens
- GPT-5.4-nano$0.20 / $1.25 per 1M tokens
- Batch / Flex processingUp to ~50% off standard
- Scale TierCustom / committed throughput
Vendor-published pricing, verified 2026-06-27 (Google Gemini API) and 2026-06-27 (OpenAI API).
SDK and language coverage
Both · 4
Python (google-genai)JavaScript/TypeScript (@google/genai)Go (google.golang.org/genai)Java (com.google.genai)
Only Google Gemini API · 2
REST APIOpenAI-compatibility endpoint
Only OpenAI API · 3
.NET / C# (official, with Microsoft)REST / HTTP APIAgents SDK (Python)
Strengths and weaknesses
- +Up to 1M-token context window, excellent for whole-codebase analysis and long-document RAG
- +Native multimodality (text, image, audio, video, PDF) in a single request
- +Among the lowest frontier prices, Flash-Lite at $0.10/$0.40 and Flash at $0.30/$2.50 per 1M
- –Reliability complaints: elevated 503/overload errors and 'infinite thinking' loops, especially on preview models
- –High time-to-first-token (~21s on 2.5 Pro) for latency-sensitive reasoning use
- –Restrictive quotas/rate limits on free and lower paid tiers cause friction
- +Access to the highest-intelligence models available, GPT-5.5 leads the Artificial Analysis Intelligence Index at 55
- +Extremely fast onboarding: self-serve key generation in under a minute and clean REST endpoints
- +First-party SDKs in Python, JS/TS, .NET, Java and Go plus an Agents SDK
- –Expensive output tokens on flagship models ($30/1M on GPT-5.5) make high-volume generation costly
- –Flagship reasoning models are slow, ~62 tok/s and ~28s TTFT on GPT-5.5 high
- –Standard pay-as-you-go tier has no uptime SLA; guarantees require Scale Tier or Azure
Google Gemini API vs OpenAI API: questions
- Which has better documentation, Google Gemini API or OpenAI API?
- OpenAI API scores higher on documentation and developer experience: 95 vs 88 out of 100.
- Which is more reliable, Google Gemini API or OpenAI API?
- OpenAI API scores higher on reliability: 90 vs 89 out of 100.
- Do Google Gemini API and OpenAI API have a free tier?
- Google Gemini API: yes (Free tier on Flash models: ~1,500 req/day, 250k TPM (Pro models paid-only since Apr 2026)). OpenAI API: no free tier.
- How are Google Gemini API and OpenAI API priced?
- Google Gemini API: Per token. OpenAI API: Per token.
- Which has more official SDKs?
- OpenAI API lists 7 official SDKs, Google Gemini API lists 6.