OpenAI API vs OpenRouter
Frontier models: GPT-5, o-series reasoning, image, audio, embeddings
vs. Unified API for 300+ LLMs across 60+ providers — 1 key, any model
Pricing tiers
OpenAI API
Free Tier (Trial)
$5 free credit for new accounts. Rate-limited.
Free
Pay-as-you-go
No monthly min. Per-token pricing by model.
$0 base (usage-based)
Usage Tiers (1-5)
Automatic tier promotion based on cumulative spend. Higher tiers = higher rate limits + new model access.
$0 base (usage-based)
Enterprise
Custom. Priority access, SLA, dedicated capacity.
Custom
OpenRouter
Free
25+ free models. 50 requests/day rate limit. 1M free requests/month base.
Free
Pay-as-you-go
5.5% platform fee on usage. Access to 300+ models, 60+ providers. High global rate limits.
$0 base (usage-based)
Enterprise
Volume-based pricing, bulk discounts, SSO/SAML, dedicated rate limits. 5M free requests/month.
Custom
Free-tier quotas head-to-head
Comparing free-tier on OpenAI API vs free on OpenRouter.
| Metric | OpenAI API | OpenRouter |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
OpenAI API · 12 features
- Assistants API — Stateful assistants with tools, threads, file search.
- Batch API — 50% discount for async processing within 24h.
- Chat Completions API — Classic /v1/chat/completions endpoint.
- Files API — Upload docs for retrieval, fine-tuning, batch.
- Fine-Tuning — Supervised + DPO fine-tuning for GPT-4o, GPT-4.1, GPT-4o-mini.
- Function Calling — JSON-schema tool calling; parallel calls supported.
- Moderation — Safety classifier API (free).
- Prompt Caching — Auto-cache repeated prefixes; 50% cheaper cached hits.
- Realtime API — WebSocket streaming voice + text with low latency.
- Responses API — Stateful conversational API.
- Structured Outputs — Enforced JSON schema compliance.
- Vision — Image input for GPT models.
OpenRouter · 15 features
- 300+ Models — Claude, GPT, Gemini, Llama, Mistral, Qwen, DeepSeek, Cohere, Grok + open-source.
- 60+ Providers — Anthropic, OpenAI, Google, Together, Fireworks, Groq, DeepInfra, Replicate, etc.
- Auto Fallback — Automatic retry to backup provider on failure.
- Bring Your Own Key — Use your own provider keys → pay providers directly + no platform fee.
- Credit System — Prepay credits via card, crypto, or bank.
- Data Retention Controls — Opt-out of training/retention per provider.
- Free Models Tier — 25+ models available at $0 (limited rate).
- Prompt Caching — Automatic cache for identical prefixes (provider-dependent).
- Provider Preferences — Pin preferred providers per request or default.
- Rankings & Stats — Public leaderboard of most-used models.
- Regional Routing — Route requests to specific geographic regions.
- Streaming — SSE + partial completions.
- Structured Outputs — JSON-mode + JSON schema across supporting models.
- Tool Use / Function Calling — Unified tool calling across providers.
- Unified OpenAI-Compat API — Same endpoint for every model + provider.
Developer interfaces
| Kind | OpenAI API | OpenRouter |
|---|---|---|
| SDK | openai-dotnet, openai-go, openai-node, openai-python | Any OpenAI SDK |
| REST | OpenAI REST API | OpenRouter API (OpenAI-compat) |
| MCP | OpenAI MCP | OpenRouter MCP |
| OTHER | Realtime API (WebSocket) | OpenRouter Dashboard |
Staxly is an independent catalog of developer platforms. Outbound links to OpenAI API and OpenRouter are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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