Criterion Gemini API and Google AI Studio OpenRouter
CategoryLLM APIs & Model PlatformsLLM APIs & Model Platforms
In one sentenceGoogle's developer API for Gemini models, with a free tier in Google AI Studio and paid tiers for production.One OpenAI-compatible API key for hundreds of models from many providers.
Problem it solvesGetting started with a capable multimodal model cheaply, and scaling to production on the same API.Managing separate accounts, keys and SDKs for every model provider, and coping with provider outages.
Free planYesYes
Developer APIYes — docsYes — docs
Open sourceNoNo
PlatformsWeb (Google AI Studio), REST APIWeb, REST API
Pricing (summary)Free tier for many Flash and Flash-Lite models with lower rate limits. Paid usage is per 1M tokens: Gemini 4 Argon $2 input / $10 output through Nov 30, 2026 (then $4 / $20); Gemini 3.8 Flash $0.75 / $3.75 through Dec 31, 2026 (then $1.50 / $7.50); Gemini 3.5 Flash-Lite $0.30 / $2.50. Batch is about half price.
Checked 2026-10-19		No subscription: inference is billed at each provider's list price, with a platform fee of 5.5% (Standard) or 8% (Business) on credit purchases. A free plan offers 25+ free models with request caps; Enterprise is contract-based.
Checked 2026-10-19
Strengths
  • Genuine free tier documented by Google
  • Very low Flash-Lite prices
  • Broad set of multimodal and speech models
  • Huge model catalogue
  • Provider list prices passed through
  • Free tier for testing
Limitations
  • Free-tier content is used to improve Google products
  • Free-tier rate limits are not published per model on the docs page
  • Several prices are introductory and scheduled to rise (Argon from Dec 1, 2026; 3.8 Flash from Jan 1, 2027)
  • 5.5% (Standard) or 8% (Business) fee on credit purchases
  • Free model caps are low
  • Another intermediary in the data path