OpenRouter vs Stainless: LLM Gateways Comparison
Compare OpenRouter and Stainless side by side. Both are tools in the LLM Gateways category.
Updated April 29, 2026
The short answer
Choose OpenRouter if largest model catalog in the gateway space — 300+ models.
Choose Stainless if automates SDK dev.
Want to compare OpenRouter and Stainless on your own traffic?
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 250+ models through one gateway. Free tier covers 10K traces per month. Setup in 5 minutes, no credit card.
Quick Comparison
| Category | LLM Gateways | LLM Gateways |
| Pricing | Free tier + pay-as-you-go (passthrough + 5.5% fee) | paid |
| Best For | Developers and teams who want one API for hundreds of LLMs without provider lock-in | AI companies and developers building API clients |
| Website | openrouter.ai | stainlessapi.com |
| Key Features |
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| Use Cases |
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Pros & Cons: OpenRouter vs Stainless
- +Largest model catalog in the gateway space — 300+ models
- +OpenAI-compatible API drops in with zero code change
- +Reasonable platform fee — 5.5% over passthrough rates
- +Per-key spend tracking and isolated rate limits
- +Active free tier viable for prototyping
- −Adds ~25-40ms latency over direct provider calls
- −Credits expire after 365 days
- −5.5% fee + $0.80 minimum charge stings on small purchases
- −Free models can be flaky — timeouts and required cooldowns
- +Automates SDK dev
- +Type-safe code
- +Multi-language
- −Requires OpenAPI
- −Limited customization
Pricing: OpenRouter vs Stainless
- · Access to 25+ free models
- · 50 requests/day (1,000 with $10+ credits)
- · 20 requests/minute
- · OpenAI-compatible API
- · 300+ models, 60+ providers
- · Passthrough provider rates + 5.5% credit-card fee
- · 5% fee on crypto purchases
- · Per-API-key spend tracking
- · Core features
- · Advanced features
- · Custom
What people are saying
Curated quotes from Hacker News, Reddit, Product Hunt, and review blogs. Dates shown so you can judge whether early criticism still applies.
- +
“OpenRouter adds 5% on top of the model provider's base prices — for a single API across 300+ models that's a fair tax.”
— Reddit user, Reddit / Toksta summary · Feb 2026 - +
“The ability to track cost of each request and separate usages through different API keys is huge for indie devs running side projects.”
— Hacker News commenter, Hacker News · Apr 2026 - ·
“OpenRouter claims ~25ms added latency in ideal conditions, with ~40ms typical — acceptable for most apps but noticeable on streaming.”
— Cost analysis, Costbench · Apr 2026 - −
“Free models are somewhat fragile with timeouts and require sleep between invocations — most users end up moving to paid models.”
— Honest review, Ofox.ai · Mar 2026
When to Choose OpenRouter vs Stainless
- Model-agnostic AI apps that swap providers freely
- Fallback routing when a primary provider is degraded
- Cost optimization across price-equivalent models
About OpenRouter
OpenRouter is a unified LLM gateway that routes requests to the best available provider for each model, with a single API key giving access to 300+ models from OpenAI, Anthropic, Google, Meta, Mistral, Cohere, and dozens of smaller providers. It exposes an OpenAI-compatible API, so any existing OpenAI SDK code works unchanged.
Two pricing tiers: a Free tier (25+ free-of-charge models, 50 requests/day, 20 RPM, raised to 1,000/day after $10+ in credits) and Pay-as-you-go (300+ models, passthrough provider rates, 5.5% platform fee on credit-card purchases / 5% on crypto). OpenRouter adds ~25-40ms latency over direct provider calls in typical conditions.
Major use cases: avoiding vendor lock-in across OpenAI/Anthropic/Google, fallback routing when a provider is down, cost optimization across price-equivalent models, and tracking spend per API key. Free credits expire after 365 days. As of 2026, OpenRouter is the most-used model gateway for AI startups and indie developers building model-agnostic applications.
About Stainless
Stainless automatically generates SDKs from OpenAPI specs. Creates production-quality type-safe SDKs in multiple languages.
What is LLM Gateways?
Unified API platforms and proxies that aggregate multiple LLM providers behind a single endpoint, providing model routing, fallback, caching, rate limiting, cost optimization, and access control.
Browse all LLM Gatewaystools →Other LLM Gateways Tools
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